All material appearing in thii report is in the public domain and may be 

reproduced or copled wlthout pemdssh; cltatiori as to sourc-3, however, is 

appreciated. 

Prager K. Infant mortalky by birthweight and other characteristics: United 

States, 1885 birth cohort. National Center for Health Statistii. Vtal Health Stat 

20(24). 1994. 

Ubnry of Congress Cataloging-in-Publkation Dsts 

Prager, Kate. 

Infant mortalky by birthweight and other characteristics: United States. 

1985 birth control I Kate Prager. 

p. cm. - (Vii1 and health statistics. Series 28, Data from the Natiinal 

VQI Statistics System: no, 24) (DHHS publkxtion; no. (PHS) 84-1852) 

“U.S. infant mortalii is analyzed for the lg85 birth cohort by birthweight, 

mother’s age. prenatal care, and other characteristics. Ths effsct of cohort and 

period on race-specific infant mortaiii rates is analyzed. The report also 

discusses the history of linked birth and infant death files in the Public Health 

Service and provides a detailed description of the methodology for creating 

linked files at the National Center for Health Statistii.” 

“Jufy lgg4.” 

Includes biblicgraphiil references. 

ISBN M408-fM88-8 

1. Infants-United States-Mortalii-Statistics. 2. United 

States-Statistics, Medical. I. We. II. Series. Ill. Series: DHHS publication: no. 

(PHS) 94-1852. 

HBI 885.A18 no. 24 

(FtJ6o.U5] 

304 6’4’0973021 s-d@0 

[30&3’4’0832] 94-10819 

CIP 

For safe by the U.S. Government Printing Oflics 

Superintendent of Documents 

Mail Stop: SSOP 

Washington, DC 28402-8828 
Vital and 

Health Statistics 

Infant Mortality by 

Birthweight and Other 

Characteristics: United 

States, 1985 Birth Cohort 

Series 20: 

Data From the National Vital Statistics System 

Nom 24 

US. infant mortality is analyzed for the 1985 birth cohort by birthweight, mother’s 

age, prenatal care, and other characteristics. The effect of cohort and period 

on race-specific infant mortality rates is analyzed. The report also discusses the 

history of linked birth and infant death files in the Public Health Service and 

provides a detailed description of the methodology for creating linked files at 

the National Center for Health Statistics. 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Public Health Service 

Centers for Disease Control and Prevention 

National Center for Health Statistics 

Hyattsville, Man/land 

Juv 1994 

DHHS Publication No. (PHS) 94-1852 
National Center for Health Statistics 

Manning Feinleib, M.D., Dr.P.H., Director 

Jack R. Anderson, Deputy Director 

Jacob J. Feldman, Ph.D., Associate Director for Analysis, 

Epidemiology, and Health Promotion 

Gail F. Fisher, Ph.D., Associate Director for Planning and 

Extramural Programs 

Peter L. Hurley, Associate Director for l&al and Health 

Statistics Systems 

Robert A. Israel, Associate Director for International 

Statistics 

Stephen E. Nieberding, Associate Director for 

Management 

Charles J. Rothwell, Associate Director for Data 

Processing and Services 

Monroe G. Sirken, Ph.D., Associate Director for Research 

and Methodology 

Office of Vital and Health Statistics Systems 

Peter L. Hurley, Associate Director 

Division of Vital Statistics 

Lester R. Curtin, Ph.D., Acting Director 

James A. Weed, Ph.D., Deputy Director 

Harry M. Rosenberg, Ph.D., ChieJ MortaZity Statistics 

Branch 

Robert L. Heuser, MA., Chief; Natalit): Marriage and 

Divorce Statistics Branch 

Mabel G. Smith, Chief; Statistical Resources Branch 

Joseph D. Farrell, Chief; Systems and Programming Branch 

Ronald Chamblee, Chiej Technica Services Branch 

George A. Gay, Chief; Registration Methods Branch 
Contents 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Highiights ............................................................................................ 

History of national linked fries in the Public Health Service ................................................... 

Methods .............................................................................................. 

Initial iinked fiie ...................................................................................... 

Followuptolinlrunlinkedrecords ........................................................................ 

Foiiowup to review accuracy of iinking ................................................................... 

Final linked file ....................................................................................... 

Birth cohort .......................................................................................... 

Residence ........................................................................................... 

File completeness ..................................................................................... 

Uniinked infant death records ........................................................................... 

Infantmortaiityrates.. ................................................................................ 

Results ............................................................................................... 

Birthweight .......................................................................................... 

Birthweight-speciik infant mortality ...................................................................... 

Gestational age ....................................................................................... 

sex ................................................................................................. 

Maternal age ......................................................................................... 

Live-birth order ...................................................................................... 

Mother’s marital status ................................................................................. 

Educational attainment of mother ........................................................................ 

Trimester prenatal care began ........................................................................... 

Detailed race ......................................................................................... 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

List of detailed tables ................................................................................... 

Appendix 

Technical notes ........................................................................................ 

Text figures 

1. Percent distribution of live births and infant deaths by birthweight and race: United States, 1985 birth cohort ........ 

2. Percent distribution of infant deaths by birthweight and age at death: United States, 1985 birth cohort. ............. 

3. Infant mortality rates by birthweight and race of child: United States, 1985 birth cohort. ......................... 

4. Infant mortality rates by gestational age and race of child: United States, 1985 birth cohort ...................... 

5. Infant mortality rates by mother’s age and race of chiid: United States, 1985 birth cohort ........................ 

6. Infant mortality rates by live-birth order and mother’s age: United States, 1985 birth cohort ...................... 

7. Infant mortality rates by race of child and mother’s marital status: United States, 1985 birth cohort ................ 

8. Infant mortality rates by race of child and mother’s education: United States, 1985 birth cohort ................... 

9. Infant mortality rates by age at death, race of child, and trimester prenatal care began: United States, 1985 birthcohort ..... 

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iii 
Text tables 

A. 

B. 

C. 

D. 

E. 

F. 

G. 

H. 

J. 

K 

Live births and infant deaths to the birth cohort and infant death records linked and not linked, by race and age at death: 

United States, 1983-85 birth cohorts . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to birthweight; 

and mortality race ratios by birthweight: United States, 1985 birth cohort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to gestational 

age; and mortality race ratios by gestational age: United States, 1985 birth cohort . . . . . . . . . . . . . . . . . . . . . . . . . . . ..I 

Sex ratios for live births and infant deaths by race and age at death, infant mortality rates by race and sex, and sex ratios 

of infant mortality rates by race: United States, 1985 birth cohort . . . ..I..................................... 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to mother’s age; 

and mortality race ratios by mother’s age: United States, 1985 birth cohort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to mother’s age 

and live-birth order; and mortality race ratios by mother’s age and live-birth order: United States, 1985 birth cohort . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to mother”s 

marital status; and mortality race ratios by mother’s marital status: United States, 1985 birth cohort . . . . . . . . . . . . . . . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to educational 

attainment for mothers 20 years of age and over; and mortality race ratios by mother’s education: United States, 1985 

birth cohort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to trimester 

prenatal care began; and mortality race ratios by trimester prenatal care began: United States, 1985 birth cohort . . . . . 

Live births and infant deaths and mortality rates according to source of race information, and ratio of infant mortality 

rates by source of race information for detailed race groups: United States, 1983-85 birth cohorts . . . . . . ..I....... 

6 

8 

12 

13 

13 

14 

15 

16 

17 

18 

Symbols 

_ _ - Data not available 

. . . Category not applicable 

- Quantity zero 

0.0 Quantity more than zero but less than 

0.05 

* Figure does not meet standard of 

reliability or precision 
Infant Mortality by 

Birthweight and Other 

Characteristics: United 

States, 1985 Birth Cohort 

by Kate Prager, Sc.D. 

Introduction 

This report presents information from the national linked 

birth and infant death data set for the birth cohort of 1985, a 

new National Center for Health Statistics (NCHS) resource for 

studying infant mortality. In the linked tile, birth ccrtifkates 

for infants born in 1985 who died before their first birthday are 

linked to death certikates for the same infants, thereby 

making available for analysis of infant mortality a large 

number of variables from the birth certificate that are relevant 

to the infant’s death. Previous national linked files were 

developed by the Division of Reproductive Health, Center for 

Chronic Disease Prevention and Health Promotion (CCDPHP), 

Centers for Disease Control and Prevention (CDC!) for the 

1980 birth cohort (l), and by NCHS for the 1960 birth 

cohort (2). 

This report is in four parts: 

The Grst part includes a brief history of linked birth and 

infant death record projects in the Public Health Service 

(PHS) and a description of the methodology by which 

linked files were created in the present project. 

The second part presents a descriptive analysis of infant 

mortality for selected variables by race for the 1985 birth 

cohort. 

The third part examines infant mortality rates for detailed 

race groups, comparing cohort and period rates. 

The final section provides detailed tables of live births and 

infant deaths and mortality rates for selected variables by 

race of child and age at death. 

NOTE: This report was prepared in the Division of Vital Statistics, under the 

general direction of Hany M. Rosenberg, Ph.D., Chief, Mortality Statistics 

Branch. The author gratefolly acknowledges the assistance of the following 

people: The linked birth and infant death data system was designed and 

programmed by David R Johnson of the Systems and Programming Branch. 

The detailed tables were programmed by David R Johnson and Gail Parr. 

Consultation to State vital statistical offices regarding collection of linked 

birth and infant death data on which this report is based was provided by 

Wilma Latta of the Technical Services Branch. Content review was provided 

by Thomas D. Dunn of the Statistical Resources Branch. The report was 

edited by Gail K Johnson and typeset by Annette F. Facemire of the 

Publications Branch, Division of Data Services. Appreciation is expressed to 

John E. Patterson, former Director of the Division of Vital Statistics, for hi 

support of the Linked Bii and Infant Death project and for his helpful 

suggestions on the report. 

In this report, detailed tables present data for the birth 

cohort of 1985 for selected infant and maternal characteristics 

by race of child and age at death for singleton and multiple 

births combined. The following major demographic and health 

variables are included: birthweight; gestational age; sex; maternal age; live-birth order; marital status; educational attainment; prenatal care; and detailed race groups, such as American 

Indian and Alaskan native, Chinese, Japanese, Hawaiian, and 

Filipino, in addition to white and black. Cause-of-death information from the linked file is not included. The analysis is 

based on data from the 1985 birth cohort except for the 

analysis of detailed races, which is based on 3 years of data for 

the 1983-85 birth cohorts, to achieve more stability among 

rates for smaller minority race groups. Data are analyzed using 

percent distributions, birth cohort infant mortality rates, and 

mortality race ratios. 

The analysis of infant mortality using birth cohort data in 

this report represents a departure from the more commonly 

used approach to analyzing infant mortality, which is usually 

in terms of period data. In period infant mortality rates, the 

numerator of the rate (deaths of infants under 1 year of age) 

and the denominator (live births) represent events that occur in 

the same period, or calendar year. In contrast, in birth cohort 

infant mortality rates, the numerator is comprised of deaths in 

the first year of life that occur in the year of birth or the 

following year to infants born in a spetied calendar year; and 

the denominator is comprised of all live born infants in the 

speci8ed year. Thus, the denominators for both the 1985 

period and 1985 birth cohort rates are the same, all infants 

born alive in 1985. However the numerator for the period rate 

is comprised of infant deaths that occurred in 1985; whereas, 

the numerator for the birth cohort rate is comprised of infant 

deaths that occurred in 1985 and 1986 to infants who were 

born in 1985. 

Birth cohort data in which the death record for the infant 

that died is linked to the birth record for the same infant 

present a special opportunity to measure race differentials in 

infant mortality more accurately than is possible with period 

data. The advantage of linked data for race-specific infant 

mortality rates derives in part from the consistent source of 

race information, the birth certificate, for both the numerator 

and denominator of the rate. The race variable for infant 

deaths in the numerator comes from the birth certificate that is 

linked to the infant’s death certificate and is therefore consistent with the source of the race variable for live births in the 

denominator. In contrast, for period rates, race information for 

1 
the denominator comes from the birth certificate, whereas race 

information for the numerator comes from a different source 

document-the infant’s death certificate. Especially for smaller 

minority races, some inconsistencies in reporting race on the 

birth and death certificates may lead to understated period 

infant mortality rates for these groups. 

Furthermore, the reporting of race information on the 

birth certificate is more accurate than on the death certificate 

(3). Accuracy of race reporting is better because on the birth 

certificate, race of each parent is usually reported by the 

mother at the time of delivery, whereas on the death certificate, race of the deceased infant is reported by the funeral 

director based on information provided by an informant or on 

observation. 

The linked record data sets for the 198385 birth cohorts 

resulted from a joint endeavor of NCHS, the States, and the 

Association of Vital Records and Health Statistics (AVRHS). 

Their development was supported with evaluation funds provided by the Assistant Secretary for Planning and Evaluation 

(ASPE), U.S. Department of Health and Human Services 

@J=w* 
Highlights 

This report presents statistical results from the national 

linked birth and infant death data set for the birth cohort of 

1985, a new NCHS resource for studying infant mortality. The 

report reviews the history and background of linked ties in the 

PHS and describes the methodology by which linked files 

were created at NCHS. The linked tile is comprised of birth 

certificates for the cohort of infants born in 1985 who died 

before their first birthday linked to death certificates for the 

same infants. An advantage of using the linked file to analyze 

infant mortality is the availability of a large number of 

variables from the birth certil%ate that are relevant to the 

infant’s death. In addition, race-specific infant mortality rates 

based on the linked file are more accurate, especially for 

smaller race groups, than period infant mortality rates published in vital Statistics of the United States, Volume LI, 

Mortality. 

For infants born in 1985, the cohort infant mortality rate 

was 10.4 deaths per 1,000 live births. Mortality before the end 

of the first year of life was strongly and inversely associated 

with the infant’s weight at birth, that is, infants of low 

birthweight were at much higher risk of death than heavier 

babies. Except at lower birthweights, black infants had higher 

mortality than white infants. Infant mortality also decreased 

markedly with increasing gestational age, with mortality higher 

for black than white infants, except among preterm births. 

Male infants had higher mortality than female infants. 

Maternal age was associated with infant mortality. The 

youngest and oldest mothers had higher infant mortality rates 

than mothers of intermediate ages. Infant mortality was lowest 

for lirst- and second-order births and increased for higherorder births. Out-of-wedlock childbearing was associated with 

elevated risk of infant death with a more pronounced effect 

among white than black mothers. 

Educational attainment of mother was inversely correlated 

with infant mortality. Rates for college graduates were less 

than half those for women who completed fewer than 8 years 

of school. While the absence of prenatal care was associated 

with high neonatal and postneonatal mortality, only postneonatal mortality was directly related to trimester prenatal care 

began. 

Race-specilic cohort infant mortality rates based on the 

national linked data set are more precise than period rates 

based on routinely available vital statistics data, especially for 

smaller race groups, because race information for both the 

numerator (infant deaths) and denominator (live births) of 

cohort rates is from the same source document, the birth 

certi&ate; and race is more accurately reported on the birth 

than death certificate. In contrast, race information for period 

rates is from two different source documents, the death 

certi8cate for the numerator and the birth certificate for the 

denominator. Based on linked file data for the birth cohorts of 

1983-85 combined, cohort infant mortality rates for the white 

population were about 3 percent lower and for the black 

population 2 percent higher than period rates. Cohort infant 

mortality rates for other minority races ranged from 19 to 

80 percent higher than period rates. 
History of national linked 

files in the Public Health 

Service 

NCHS undertook its first major effort to create a national 

file of linked birth and infant death records for the birth cohort 

of 1960 (2). The file was constructed by collecting actual 

copies of linked birth and death certificates from each of the 

50 States and preparing punched cards for each pair of 

certificates. Of the nearly 110,000 infant deaths to the 1960 

birth cohort, certificates for 97.4 percent were matched to the 

corresponding live birth certificates. The infant mortality rate 

based on the 1960 birth cohort linked file was 25.1 per 1,000 

live births. 

The next national file was created for the birth cohort of 

1980 by the Division of Reproductive Health, CCDPHP, CDC, 

in a project called National Infant Mortality Surveillance 

(NIMS) (1). NIMS provided not only valuable data but also 

the occasion for an important forum, the NIMS Conference, 

held on May 1, 1986, in Atlanta, Georgia. This conference 

brought together for the first time representatives from State 

maternal and child health programs and State vital statistics 

offices to exchange information on data needed to monitor the 

effectiveness and efficiency of maternal and child health 

programs. 

In 1985, NCHS initiated a two-stage evaluation project to 

determine the feasibility of creating linked birth and infant 

death files on a routine, annual basis as part of the Vital 

Statistics Cooperative Program (VSCP) of NCHS and the 

States. In stage 1, a linked file was produced with a match rate 

of 96.7 percent for the 1982 birth cohort of infant deaths that 

occurred in a nine-State area (4). Stage 1 demonstrated both 

the feasibility of using a new methodology for creating the 

linked file on a routine basis, as well as the importance of 

followup to link birth and death certificates that were not 

linked initially. Follownp linking not only increased the overall match rate but also reduced geographic and demographic 

biases in the linked file before followup. 

In stage 2 of the evaluation project, State and national 

linked files for each of the birth cohorts of 1983-136 were 

formally evaluated at two evaluation meetings. In March 

1988, at the first evaluation meeting in San Diego, California, 

quality and completeness of the 1983 birth cohort national 

linked file were evaluated, and a variety of technical and 

methodological issues were considered. In addition, State 

linking and registration procedures that contributed to more 

complete and high quality State and national linked filles were 

identified. In November 1989, at the second evaluation meeting in Houston, Texas, trends in quality and completeness of 

linked files were evaluated (5). The meeting also focused on 

use and interpretation of linked data at the State and national 

levels. 
Methods 

The national file of linked birth and infant death records 

was created in two stages. First, State vital statistics offices 

provided NCHS with certificate numbers from State linked 

files that identified linked birth and death records for deceased 

infants. With these identifying certilicate numbers, NCHS 

created an initial fle by accessing records identified by the 

State-provided certificate numbers in the NCHS natality and 

mortality statistical files. Second, a Gral file was processed in 

which additional records linked during followup added to the 

initial file. 

Thus, the national linked birth and infant death file was 

created by taking advantage of two existing data sources that 

will be described in detail. 

1. State linked ties that provide certificate numbers to identify linked birth and death certificates for deceased infants; 

2. NCHS natality and mortality statistical files that provide 

coded information from birth and death certificates. 

Vially all States routinely link death certificates for 

infants to birth certikates corresponding to the same infants 

for legal and statistical purposes. Most States, therefore, can 

fairly readily generate files of linked birth and death events for 

infants, particularly when both the birth and infant death occur 

in the same State. When the birth and death of an infant occur 

in different States, linking the two certificates that are filed in 

different jurisdictions requires State vital statistics offices to 

cooperate in the exchange of vital records. In accordance with 

the terms of the “Association for Vital Records and Health 

Statistics Agreement for Administering the Vital Records 

Exchange System,” copies of vital records are exchanged by 

the State of death and State of birth to effect a link. In 

addition, if a third State is identified as the State of residence 

at the time of birth or death, that State is also sent a copy of 

the appropriate certificate by the State where the birth or death 

occurred. These existing State linked tiles greatly facilitated 

the development of national linked files. 

The NCHS statistical Gles include data from birth and 

death certificates provided to NCHS by States under the 

VSCR The data have been coded according to uniform coding 

specifications, have met NCHS quality control standards, have 

been edited and reviewed, and are the basis for official U.S. 

natal@ and mortality statistics (6). The NCHS statistical files 

are the source of live birth and infant death computer records 

from which the national linked file is created. For the 1985 

birth cohort linked file, statistical records of live births that 

occurred in 1985 in the United States were linked to statistical 

records of deaths to these same infants who died in 1985 or 

1986 before their first birthday. 

Initial linked file 

To create the initial tie, NCHS obtained linked ties on 

magnetic tape from those States that had them and extracted 

only birth and death certikate numbers for linked records and 

State and year of occurrence. Five States without computerized linked Rles-Alaska, Arizona, Delaware, Indiana, and 

Nevada-posted certificate numbers for linking birth certificates on a computer-generated list of infant death certificate 

numbers that was produced by NCHS. Using certificate numbers provided by the States, NCHS selected and linked birth 

and death records from NCHS natality and mortality statistical 

ties and created a single statistical record containing coded 

information from two previously separate records. These new 

statistical records comprised the initial national file of linked 

birth and infant death records. 

Followup to link unlinked records 

NCHS then followed up with State vital statistics offices 

to link infant death certikates not linked in the initial tile; and 

to review linked records with inconsistent data. To link 

unlinked death certificates, NCHS returned copies or computer 

lists of unlinked infant death certificates to States of death. If 

the birth occurred in a State different from the State of death, 

the State of birth identified on the death certificate was 

contacted to obtain the linked birth certificate. Some records in 

State linked files were not linked in the NCHS initial file 

because the birth record had been renumbered or had been 

tiled in the State after NCHS closed its statistical files. If the 

linked birth certificate from another State had been renumbered, the State of death requested the original certificate 

number from the State of birth. If the linked birth certilicate 

had been filed after NCHS closed its statistical llles, the State 

provided NCHS with a copy of the late-filed birth certificate 

so it could be added to the linked file data set. 

Followup to review accuracy of linking 

Lied records with inconsistent data were reviewed to 

ensure that the birth and death records were linked correctly. 

Accuracy of linking was determined by measuring consistency 

between the following four statistical items common to both 

5 
the birth and death records: date of birth, sex, State of birth, Residence is determined by the mother’s usual place of 

and race. A list of linked records failing the consistency check residence at the time of the infant’s birth. Excluded from the 

as well as unlinked death records were returned to States for linked file are deaths that occurred outside the United States to 

review. In the 1985 initial file, of the 707 records that failed infants born in the United States, deaths that occurred in the 

the consistency check, 91 were found to be mismatched and United States to foreign-born infants, and births and. deaths 

were corrected. that occurred outside the United States to U.S. residents. 

Final linked file 

Upon the completion of followup, NCHS processed the 

linked file by correcting linked records that were mismatched 

in the initial lile and by adding late-filed birth certificates to 

the linked file data set. Certificates that were added to the data 

set were coded, keyed, and processed before they were added 

to the denominator or birth cohort file. Then they were linked 

to infant death records and added to the numerator or linked 

file. The addition of late-filed birth records to the linked file 

data set results in a denominator file that is not identical to the 

NCHS natality statistical file. 

Birth cohort 

A birth cohort of infant deaths is comprised of deaths 

under 1 year of age that occur in the year of birth or the 

following year to infants born in a specified calendar year. The 

1985 birth cohort national linked birth and infant death data 

set includes all infants born in 1985 in the United States who 

died in 1985 or 1986 (also in the United States) before their 

first birthday. 

Residence 

While the national linked file includes linked statistical 

records for births and deaths that occurred in the United States 

to U.S. residents and nonresidents, with one exception, only 

data for U.S. residents are analyzed and presented in this 

report. The one exception is the analysis of file completeness, 

which is based on all infant death occurrences, as shown in 

table A. 

Table A. Live births and infant deaths to the birth cohort and 

infant death records linked and not linked, by race and age at 

death: United States, 1983-85 birth cohorts 

Linked status of 

infant death records 1983 

Birth cohort 

1984 1985 

Number 

Live births. . . . . . . . . . . . . _ . . 3,643,001 3.673.693 3,765,336 

Infant deaths . . . . . . . . . . . . _ . . 40,349 39,167 39,943 

Linked.................. 39,704 38,314 39,170 

Not linked. . . . . _ . . . . . . . 645 853 773 

Percent 

!-inked . . 96.4 97.6 96.1 

White. . . 90.5 98.0 98.2 

Black. . . . 98.0 97.5 97.8 

Neonatal. . 98.2 97.9 98.1 

Postneonatal 90.6 97.7 98.0 

Not linked . 1.6 2.2 1.9 

NOTE: Includes Iw births and infant deaths tit occurred in the United States, regardless of 

residence. 

File completeness 

File completeness is based on the percent of records for 

infant deaths to the birth cohort that were linked to birth 

records for the same infants. The percent is based on all infant 

deaths to the birth cohort that occurred in the United States, 

regardless of residence at birth, because birth residence is 

unknown for unlinked infant death records. Deaths to infants 

known to be born outside the United States are not included in 

the calculation of percent linked. 

The percent of infant death records linked with their 

corresponding birth records was 98.1 percent for th.e 1985 

birth cohort (table A). A slightly larger percent was linked for 

white than black infants, 98.2 and 97.8 percent, respectively. 

The difference in percent linked for neonatal and postneonatal 

deaths was very small, 98.1 and 98.0 percent, respectively. 

Because the analysis is based on linked infant death records 

and does not include unlinked records for infant deaths, rates 

are understated by 1.9 percent, on the average. 

Unlinked infant death records 

In the 1985 birth cohort, 773 records for infant deaths 

were not linked (table A). Deaths to foreign-born infants were 

not counted among the not linked, regardless of mother’s 

country of residence. An analysis of the characteristics of 

unlinked records revealed that distributions by race and age at 

death were similar to those of linked records; but that a larger 

proportion of the unlinked compared with the linked records 

represented events in which the birth and death occurred in 

different States. 

Infant mortality rates 

Infant mortality rates in this report are calculated by 

dividing the number of infant deaths to the birth cohort by the 

number of live births in that cohort. Such measures are called 

“cohort” infant mortality rates. 

In contrast, “period” rates published annually lin Wtal 

Statistics of the United States, Volume IZ, Mortality are calculated by relating the aggregate number of infant deaths in a 

calendar year to the number of live births in the same year. 

Period rates approximate the risk of infant death in populations in which the number of births is not changing rapidly 

from year to year (7,8). Because period mortality rates are 

based on natality and mortality data from a single calendar 

year, they can be produced on a more timely basis than cohort 

rates. 
Cohort rates more accurately measure infant mortality information for both the numerator and denominator comes 

risk than period rates because the denominator includes the from the same source record, the birth certificate; and race is 

total population of infants at risk; every child whose death is better reported on the birth than death certi&ate. Thus, cohort 

counted in the numerator is also included in the denominator. rates are not subject to inconsistencies between the numerator 

Cohort rates are also more accurate than period rates because and denominator that can affect period rates. 
Results 

A total of 3,760,833 U.S. resident infants were born in weight (weighing at least 2,500 grams or 5 pounds 8 ounces at 

1985. (NOTE: NCHS previously published a total of 3,760,561 birth) (table B). In contrast, low birthweight babies (weighing 

infants born in 1985 in the United States (9). In creating the less than 2,500 grams at birth) comprised only 6.8 percent of 

national birth cohort linked data set, birth records were added all live births but 61.1 percent of all infant deaths. Thus, the 

for infants registered after the NCHS natality statistics file was majority of infant deaths occurred to a very small proportion 

closed--see Methods section.) Of the infants born in 1985, of all live births, those weighing less than 2,500 grams at 

39,145 died before their first birthday, resulting in an infant birth. While comprising only 1.2 percent of all live births, 

mortality rate for the 1985 birth cohort of 10.4 infant deaths infants of very low birthweight (weighing less than 1,500 

per 1,000 live births. This was the same rate as for the 1984 grams or 3 pounds 4 ounces at birth) accounted for almost 

birth cohort and 5 percent below the rate of 10.9 for the 1983 one-half, 45.8 percent, of the infant deaths. Among white 

birth cohort. For white infants born in 1985, the rate was 8.9 infants, low birthweight characterized 5.6 percent of the births 

compared with a rate of 18.3 for black infants. For the birth and 57.9 percent of the deaths; and among black infants, low 

cohorts of 1983 and 1984, rates for white infants were 9.3 and birthweight characterized 12.4 percent of the births and 69.4 per8.9, and for black infants, 18.9 and 17.9, respectively. cent of the deaths. 

The 1985 birth cohort infant mortality rate of 10.4 deaths 

per 1,000 live births compares with a period infant mortality 

rate of 10.6 in 1985, reflecting infant deaths and live births 

occurring in the same calendar year. The cohort rate is 

1.9 percent less than the period rate, corresponding to 1.9 percent of the infant deaths to the cohort that were not linked. 

Birthweight 

The percent distribution of all live births by birthweight is 

unimodal, with a peak at 3,000-3,499 grams or 6 pounds 10 

ounces-7 pounds 11 ounces for all races combined as well as 

for the two major race groups, white and black (figure 1). For 

black infants the birthweight distribution is shifted toward 

lower birthweights than the corresponding distribmtion for 

white infants, illustrating the higher percent of low birthweight 

births among the black than white population. 

For the 1985 birth cohort, 93.2 percent of all live births 

and 38.9 percent of all infant deaths were of normal birthIn contrast, the distribution of infant deaths by birthweight is bimodal, with a primary peak at birthweights of 

Table q . Percent distribution of live births and infant deaths and Infant mortality rates by race of child, according to birthweight; and 

mortality race ratios by birthweight: United States, 1999 birth cohort 

Birthweight 

Live births Infant deaths Infant mortality 

Race ratio 

All races White Black All races white Black All races White Black black:white 

Percent distribution Rate per 1,000 live births 

All birthweights . . . . . . . . 100.0 100.0 100.0 100.0 100.0 100.0 10.4 8.9 18.3 2.06 

Less than 2,500 grams . . . . 6.0 5.6 12.4 61 .l 57.9 69.4 94.5 91.5 102.7 1.12 

Less than 500 grams. . . . 0.1 0.1 0.3 11.4 9.5 16.2 896.9 900.3 890.7 0.99 

500-999 grams . . . . . . . 0.5 0.4 1.1 25.0 23.6 31 .a 561.5 582.7 526.7 0.90 

l,WO-1,499 grams _ . . . . 0.6 0.5 1.2 8.6 9.1 7.5 145.5 162.1 110.0 0.68 

1,500-1,999 grams.. . . . 1.3 1.1 2.4 6.7 7.0 6.0 53.9 57.8 45.3 0.78 

2,OOO-2,499 grams . . . . . 4.2 3.6 7.4 8.5 8.8 7.8 20.8 21.4 19.3 0.90 

2,500 grams or more . . . . . 93.2 94.4 87.6 38.9 42.1 30.6 4.3 3.9 6.3 1.62 

2.500-2,999 grams.. . . . 15.9 14.1 23.6 12.0 12.2 11.4 7.8 7.6 6.7 1.14 

3,000-3,499 grams. . . . . 36.7 36.1 38.3 15.1 16.2 12.0 4.2 3.9 5.6 1.44 

3,500-3,999 grams. . . . . 29.6 31.7 20.3 8.4 9.6 5.2 2.9 2.7 4.6 1.70 

4,000-4,499 grams . . . . . 9.2 10.3 4.5 2.5 3.0 1.3 2.8 2.6 5.4 2.08 

4,500+999 grams . . . 1.7 1.9 0.7 0.6 0.7 0.3 3.8 3.4 8.1 2.38 

5,000 grams or more. . . 0.2 0.2 0.1 0.3 0.3 0.3 14.8 11.5 56.5 4.91 

NOTE: Figures may not add to total due to rounding. 

8 
35 

25 

20 

15 

10 

5 

0 

Live births 

H AII races 

+-*White 

* - - * Black 

Infant deaths 

ii% 

500 

% - l,ooO- 1,999 1,500-,999 2,000-499 2,500-999 3,000-499 

Birthweight in grams 

3,500-999 4,000-499 4,500-999 or 5,000 more 

rlgure 1. Percent distribution of live births and infant deaths by birthwelght and race: United States, 1985 birth cohort 

500-999 grams or 1 pound 2 ounces-2 pounds 3 ounces and a 

secondary peak at 3,000-3,499 grams, the latter peak corresponding to the peak in the live birth distribution (figure 1). A 

larger proportion of black deaths than white deaths were to 

infants weighing less than 1,500 grams, 55.5 and 42.2 percent, 

respectively. 

As age at death increases, the birthweight distribution of 

the deaths shifts from the lower peak at 50&999 grams to the 

higher peak at 3,00&3,499 grams (figure 2). Deaths in the 

early neonatal period, O-6 days, are concentrated in the lower 

peak; deaths in the postneonatal period, 28 days-11 months, 

are concentrated in the higher peak; and late neonatal deaths in 

the intermediate period, 7-27 days, are distributed between 

both peaks. 

Birthweight-specific infant mortality 

Infant mortality rates are inversely related to birthweight, 

that is, rates decrease as birthweight increases, up to 4,500 

grams or 9 pounds 14 ounces for infants of all races combined 

(figure 3 and table B). At birthweights greater than 4,500 

grams, rates increase somewhat. For the 1985 birth cohort for 

all races combined, the mortality rate for infants of low 

birthweight (less than 2,500 grams or 5 pounds 8 ounces) was 

94.5 deaths per 1,000 live births, 22 times the rate of 4.3 for 

normal weight infants (2,500 grams or more). The rate for 

infants of very low birthweight (less than 1,500 grams or 3 

pounds 4 ounces) was 390.0 per 1,000 (rate computed from 

data in table l), 90 times the rate for normal weight infants. 

The lowest infant mortality rate for all races combined was 2.8 

deaths per 1,000 infants weighing 4,000-4,499 grams or 8 

pounds 14 ounces-9 pounds 14 ounces at birth. 

Mortality among black infants, 18.3 deaths per 1,000 live 

births, was more than two times that of white infants, 8.9, as 

indicated by a mortality race ratio (ratio of black to white 

infant mortality rates) of 2.06 (table B). However, at birthweights below 2,500 grams where the risk of death is greater, 

mortality race ratios of less than 1.00 indicate that black 

infants have a mortality advantage relative to white infants. 

For example, at birthweights of l,OOO-1,499 grams, mortality 

for black infants (110.2 infant deaths per 1,000 live births) was 

32 percent lower than that for white infants (162.1). The 

9 
40 

38 

36 

34 

32 

30 

26 

26 

24 

22 

20 

18 

16 

14 

12 

10 

8 

6 

4 

2 

0 

- Early neonatal 

l - Post neonatal 

I’ 

I ’ 

I ’ 

, 

\ 

I \ 

I \ 

I \ 

\ 

Less 

than 

500 

500- 

999 

1 ,ooo1,499 1,500- 

1,999 

2,000- 

2,499 

2,500 - 3,000- 3,500 - 4,000- 4,500- 5,000 

2,999 3,499 3,999 4,499 4,999 or more 

Birthweight in grams 

Figure 2. Percent distribution of infant deaths by blrthweight and age at death: United States, 1995 birth cohort 

mortality differential by race narrowed from 0.68 to 0.90 as 

the corresponding birthweights increased from l,OOO-1,499 to 

2,000-2,499 grams, respectively. 

At birthweights of 2,500 grams and over where the risk of 

death is lower, mortality race ratios of greater than 1.00 

indicate that black infants had a mortality disadvantage relative to white infants that steadily increased as birthweight 

increased (table B). A mortality race ratio of 1.14 for infants 

weighing 2,500-2,999 grams or 5 pounds 9 ounces-6 pounds 

9 ounces indicates that mortality was 14 percent greater among 

black than white infants. The mortality race ratio increases to 

a maximum of 4.91 for infants weighing 5,000 grams or 11 

pounds 1 ounce or more. 

The foregoing analysis of birthweight-specific infant mortality does not take into account that live births to the white 

population and live births to the black population have unique 

birthweight distributions and mean birthweights specific for 

the race (see figure 1 and table B). In another type of analysis 

pioneered by Wilcox and Russell (lo), the population mean 

birthweight is assumed to be an important parameter when 

comparing infant mortality between races. In the Wilcox and 

10 

Russell model, infant mortality for the black race and white 

race is compared for babies whose weight at birth deviates 

from the population mean birthweight by standard amounts 

called standard deviations from the mean. In contrast, in the 

previous analysis, birthweight-specific infant mortality rates 

were compared for black infants and white infants of the same 

absolute birthweight and showed a relative survival advantage 

for black infants weighing less than 2,500 grams at birth. 

According to Wilcox and Russell, when birthweight distributions are standardized, the relative survival advantage of lower 

birthweight black infants disappears. 

Gestational age 

In the 1985 birth cohort, 90.2 percent of all live births and 

42.3 percent of all infant deaths were full term, that is, born at 

37 or more completed weeks of gestation (table C). In contrast, preterm babies (born before 37 weeks of gestation) 

comprised only 9.8 percent of all live births but 57.7 percent 

of all infant deaths. Thus, the majority of infant deaths 

occurred to a small proportion of all live births, namely, those 

born preterm. 
10 - 

L 

6 - 

5 - 

4- 

3 - 

Black 

All races 

White 

Lessthan 

500 

500- 

999 

1 ,ooo1,499 1,500- 

1,999 

2,000- 2,500- 3,000- 

2,499 2,999 4499 

Birthweight in grams 

3,500- 

3,999 

4,000- 

4,499 

4,500- 5,000 

4,999 or more 

Figure 3. Infant mortality rates by birthweight and race of child: Unlted States, W85 birth cohort 

The proportion of preterm live births and infant deaths where the risk of death was higher, black infants had a 

differed for the two major race groups. More than twice the mortality advantage relative to white infants. For example, at 

proportion of black births (17.6 percent) as white births (8.2 per- gestational ages of 28-31 weeks, the mortality race ratio of 

cent) was pretenn. The proportion preterm among infant 0.72 indicates that mortality for black infants (75.0 deaths per 

deaths was also larger for the black than the white population, 1,000 live births) was nearly 30percent less than the corre66.2 percent compared with 54.6 percent, respectively. sponding rate for white infants (104.2). 

Preterm birth was associated with a higher risk of death 

than full-term birth. Infant mortality rates were inversely 

related to gestational age, that is, rates decreased as gestational 

age increased, up to 40 weeks gestation for infants of all races 

combined (table C and figure 4). For infants of gestations 

longer than 41 weeks, mortality increased somewhat. For the 

1985 birth cohort for all races combined, mortality decreased 

steadily from 435.4 infant deaths per 1,000 preterm births of 

less than 28 weeks to 4.1 for infants of 40 and 41 weeks 

gestation. 

At gestations of at least 36 completed weeks where the 

risk of death was lower, mortality race ratios greater than 1.00 

indicate that black infants have a mortality disadvantage 

relative to white infants. For example, a mortality race ratio of 

1.97 for infants born after 40 completed weeks of gestation 

indicates that mortality for black infants (7.1 deaths per 1,000 

live births) was nearly twice that for white infants (3.6). 

Sex 

Although mortality among black infants was more than 

twice that among white infants for babies born prior to 36 

completed weeks of gestation, mortality rates for black infants 

were lower than for white infants as indicated by mortality 

race ratios of less than 1.00 (table C). Thus, at short gestations 

In the 1985 birth cohort, the sex ratio was 1,052 males per 

1,000 females, 1,056 for the white population and 1,030 for 

the black population (table D). The sex ratio for infant deaths 

of all races combined was considerably higher than that for 

live births, 1,347; the ratio was 1,394 and 1,237 for the white 

11 
Table C. Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to gestatlonal age; and 

mortality race ratios by gestational age: United States, 1985 birth cohort 

Gestational age 

Live births Infant deaths Infant mortality 

Race ratio 

All races White Black All m33-s whit.9 Black All races White Black blackcwhite 

All births ............. 

Less than 28 weeks. .... 

28-31 weeks ......... 

32-35 weeks ......... 

36 weeks. ........... 

37-39 weeks ......... 

40 weeks. ........... 

41 weeks. ........... 

42 weeks and over. ..... 

100.0 100.0 

Percent distribution 

100.0 100.0 100.0 100.0 

Rate per 1,000 live births 

10.4 8.9 18.3 

0.8 0.6 2.0 33.8 30.0 43.8 435.4 455.4 408.2 0.90 

1.1 0.9 2.4 10.1 10.2 9.9 93.5 104.2 75.0 0.72 

4.7 3.9 8.4 10.1 10.5 9.0 22.6 24.0 19.7 0.82 

3.2 2.9 4.8 3.7 3.8 3.5 11.9 11.6 13.1 1.13 

38.7 37.9 41.4 20.1 21.2 17.1 5.4 5.0 7.5 1.50 

22.1 22.9 17.9 8.6 9.2 7.0 4.1 3.6 7.1 1.97 

15.2 16.2 11.0 6.0 6.7 4.3 4.1 3.7 7.1 1.92 

14.2 14.7 12.1 7.5 8.3 5.5 5.5 5.0 8.4 1.68 

2.08 

NOTE Figures may not add to total due to rounding. 

20 

2 

1 I I I I I I I I 

I;izrT 28-31 32-35 36 37- 39 40 41 420r 

n-me 

28 

Weeks of gestation 

Figure 4. Infant mortality rates by gestational age and race of child: Unlted States, 1985 birth cohort 

and black populations, respectively. Infant mortality rates were combined, rates for males (11.7 infant deaths per 1,000 live 

consistently higher for males than females, as indicated by births) were 29 percent higher than rates for females (9.1). For 

mortality sex ratios greater than 1.00 (table D). For all races the white and black populations, infant mortality rates for 

12 
Table D. Sex ratios for live births and infant deaths by race and 

age at death, infant mortality rates by race and sex, and sex 

ratios of infant mortality rates by race: United States, 1995 birth 

cohort 

Age and sex 

Live births. . . . . . . . . . . _ . . . 

Infant deaths . . . . . . . . . . . . . 

Neonatal. . . . . . . . . . . . . . . 

Postneonatal . . . . . . . . . . . . 

Both sexes. . . . . . . . . . . . . . . 

Male . . . . . . . . . . . . . . . . . 

Female . . . . . . . . . . . . . . . 

Malezfemale . . . . . . . . . . . . . . 

All reces White Black 

Males per 1,000 females 

1,052 1,056 1,030 

1,347 1,394 1,237 

1,331 1,369 1,242 

1,377 1,443 1229 

Deaths per 1,000 live births 

10.4 8.9 18.3 

11.7 10.1 20.0 

9.1 7.6 16.6 

Ratio of infant mortality rates 

1.29 1.33 1.20 

males exceeded those for females by 33 and 20 percent, 

respectively. 

Maternal age 

In the 1985 birth cohort, the distributions of live births 

and infant deaths by maternal age were similar. However, 

mothers whose babies died in the 8rst year of life tended to be 

younger than all mothers giving birth in 1985 (table E). While 

over one-half (51.3 percent) of the infant deaths were to 

mothers under 25 years of age, only 43.0 percent of all births 

were to mothers of that age. 

The youngest and oldest mothers showed the highest risk 

of infant mortality while mothers in the age groups 25-29 and 

30-34 years showed the lowest risk. Infant mortality rates for 

the birth cohort of 1985 for all races combined decreased as 

mother’s age increased to 30-34 years. Rates increased for 

infants of mothers age 35 years and over (table E and figure5). For mothers under 15 years, the rate was 22.0 deaths 

per 1,000 live births, decreasing to a low of 8.6 for mothers 

30-34 years and increasing for older mothers to a high of 23.2 

for mothers 45-49 years. 

The same U-shaped pattern of infant mortality by maternal age applied to both white and black mothers. But black 

mothers were more likely than white mothers to experience 

infant death as indicated by mortality race ratios that exceeded 

1.00 at every age (table E and figure 5). The differential in 

infant mortality by race was greatest for the low risk maternal 

age groups of 25-29 and 30-34 years, as indicated by 

mortality race ratios of 2.31 and 2.29, respectively. 

Live-birth order 

In the 1985 birth cohort, the distributions of live births 

and infant deaths by live-birth order were similar. Threefourths (74.8 percent) of all live births and 71.1 percent of all 

infant deaths were first- or second-order births (table F). Infant 

mortality experienced by mothers of all ages and races combined was lowest for first- and second-order births, 10.0 and 

9.8 deaths per 1,000 live births, respectively, and increased to 

10.9 and 13.6 for third- and fourth- and higher-order births, 

respectively (table F and figure 6). 

Mortality patterns by live-birth order differed substantially for mothers of different ages. At younger ages, risks 

increased with birth order while at older ages, risks showed a 

U-shaped pattern of association with live-birth order. For 

example, among the youngest mothers, those under 20 years 

of age, mortality increased steeply with increasing live-birth 

order. Mortality among fourth- and higher-order births (33.0 

infant deaths per 1,000 live births) was 2.5 times that among 

Grst-order births (13.2). Among mothers in the prime childbearing ages of 20-34 years, mortality for first-order births 

(8.9 deaths per 1,ooO) did not differ substantially from mortality for second-order births (9.0). Mortality increased to 14.0 

infant deaths per 1,000 live births for fourth- and higher-order 

births (table F and figure 6). Among older mothers 35-49 

years, mortality for first-order births (11.4 infant deaths per 

1,000 live births) was elevated relative to second- and thirdorder births (8.9 and 9.5, respectively) and similar to that for 

fourth- and higher-order births (11.5). 

At every live-birth order, infant mortality for black mothers was twice that for white mothers (table F). For high risk 

Table E. Percent distribution of live births and Infant deaths and infant mortality rates by race of child, according to mother’s age: and 

mortality race ratios by mother’s age: United States, 1995 birth cohort 

Live births Infant deaths Infantmortaii@ 

Race ratio 

Mother’s age All races white Black All races W77lte Black All rac8s White Black blackwhite 

Percent distribution Rate per 1,000 live births 

All ages ............. loo.0 100.0 loo.0 100.0 100.0 100.0 10.4 8.9 18.3 2.06 

Under 20 years. ........ 12.7 10.8 23.0 18.5 16.0 25.1 15.1 13.1 19.9 1.52 

Under 15 years ....... 0.3 0.1 1.0 0.6 0.3 1.2 22.0 20.7 23.7 1.14 

15-19 years ......... 12.4 10.7 22.1 17.9 15.6 23.6 15.0 13.0 19.7 1.52 

20-24 years. .......... 30.3 29.9 34.1 32.8 32.5 34.1 11.3 9.6 18.3 1.91 

25-29 years. .......... 31.9 33.3 25.0 27.0 28.4 23.7 8.8 7.5 17.3 2.31 

30-34 years. .......... 18.5 19.4 12.8 15.3 16.5 12.0 8.6 7.5 17.2 2.29 

35-39 years. .......... 5.7 5.8 4.3 5.4 5.7 4.3 9.9 8.8 18.4 2.09 

40-44 years. .......... 0.8 0.7 0.6 0.9 0.9 0.7 12.4 10.8 19.8 1.83 

45-49 years. .......... 0.0 0.0 0.0 0.1 * * 23.2 * * * 

NOTE: Figures may not add to total due to rounding. 

13 
All races 

Under 15 15-19 20- 24 25-29 30-34 35-39 40-44 45-49 

Age in years 

Table F. Percent distribution of live blrths and infant deaths and infant mortality rates by race of child, according to mother’s age aind 

live-birth order; and mortality race ratios by mother’s age and live-birth order: United States, 1999 birth cohort 

Mother’s age and 

live-birth order 

Live births Infant deaths Infant mortalky 

Race ratio 

All races White Black All races white Black All races White Black blackwhite 

All mothers ........... 

First child ........... 

Second child ......... 

Third child. .......... 

Fourth child and over. ... 

Mothers under 20 years ... 

First child ........... 

Second child ......... 

Third child. .......... 

Fourth child and over. ... 

Mothers 20-34 years ..... 

First child ........... 

Second child ......... 

Third child. .......... 

Fourth child and over. ... 

Mothers 3H9 years ..... 

First child ........... 

Second child ......... 

Third child. .......... 

Fourth child and over. ... 

100.0 100.0 

41.6 42.1 

33.2 34.0 

15.6 15.4 

9.5 6.5 

100.0 100.0 

77.6 60.1 

16.4 17.1 

3.3 2.5 

0.5 0.3 

100.0 100.0 

37.6 39.0 

36.0 36.7 

17.0 16.4 

9.1 7.8 

100.0 100.0 

17.9 18.6 

27.1 27.8 

22.9 23.2 

32.1 30.4 

Percent distribution 

100.0 100.0 

39.4 39.9 

29.6 31.2 

17.0 16.4 

13.6 12.4 

100.0 100.0 

72.7 68.0 

21.3 25.0 

5.0 5.9 

1.0 1.1 

100.0 100.0 

30.6 34.7 

33.1 33.4 

20.4 16.6 

15.9 13.2 

100.0 100.0 

12.9 19.8 

21.5 23.4 

21.8 21.1 

43.7 35.7 

100.0 100.0 

41.1 37.6 

32.7 28.1 

15.6 17.7 

10.5 16.6 

100.0 100.0 

71.3 63.5 

23.9 26.3 

4.3 6.1 

0.5 2.1 

100.0 100.0 

36.7 29.6 

35.0 29.5 

17.6 21 .o 

10.8 19.9 

100.0 100.0 

20.2 18.7 

25.4 17.6 

21.5 20.4 

32.9 43.3 

Rate per 1,000 live births 

10.4 8.9 18.3 

10.0 6.7 17.5 

9.6 6.5 17.3 

10.9 9.1 19.1 

13.6 10.9 22.0 

15.1 13.1 19.9 

13.2 11.7 17.4 

20.5 16.3 24.5 

27.2 22.6 32.1 

33.0 22.5 42.1 

9.7 6.3 17.6 

6.9 7.6 17.2 

9.0 7.9 15.9 

10.6 6.9 16.2 

14.0 11.2 22.2 

10.3 9.0 18.t 

11.4 9.8 27.0 

8.9 8.3 15.2 

9.5 8.4 17.5 

11.5 9.8 16.5 

2.06 

2.01 

2.04 

2.10 

2.02 

1.52 

1.49 

1.34 

1.42 

1.07 

2.14 

2.21 

2.01 

2.64 

1.98 

2.68 

2.76 

1.33 

2.08 

1.39 

NOTE: Figures may not add to total due to rounding. 

14 
35 - Mother’s age 

~ ,a Under2Oyears 

30 - **- 

/ 

25 - 

E . 

l 

s 

?J 20 - 

z 

Q 

?= 

,/= * 

85 15 - 

5 - 

0 I 

1 

. I I 

2 3 4 or more 

Live-birth order 

Figure 6. Infant mortality rates by live-birth order and mother’s age: United states, 1985 birth cohort 

mothers under 20 years of age, mortality race ratios were 

generally smaller at every birth order than for older mothers. 

deaths per 1,000 live births, respectively. For the black 

population, the corresponding rates for unmarried and married 

mothers were 20.5 and 15.1, respectively. The mortality race 

Mother’s marital status 

For the 1985 birth cohort, 22.0 percent of all live births 

and 35.3 percent of all infant deaths were to unmarried 

mothers (table G). The distributions of live births and infant 

deaths by marital status differed substantially between the two 

major race groups. For the black population, 60.1 percent of 

live births and 67.1 percent of the infant deaths were to 

unmarried mothers compared with only 14.5 percent live 

births and 22.4 percent infant deaths for the white population. 

Births to unmarried women were associated with elevated 

risk of infant death. For all races combined, the infant 

mortality rate for unmarried mothers (16.7 deaths per 1,008 

live births) was nearly twice that for married mothers (8.6) 

(table G and figure 7). For the white population, infant mortality for unmarried and married mothers was 13.7 and 8.0 infant 

ratio for lower risk married mothers (1.89) was larger than that 

for higher risk unmarried mothers (1.50) (table G). 

Educational attainment of mother 

In the 1985 birth cohort among mothers 20 years of age 

and over, 14.6 percent of the live births and 21.6 percent of the 

infant deaths were to mothers who had not 8nished high 

school (table H). Infant mortality rates were inversely related 

to years of schooling completed (table H and figure 8). For all 

races combined, mortality was 12.8 infant deaths per 1,000 

live births for mothers who completed 8 or less years of 

education, 10.2 for high school graduates, and 7.0 for college 

graduates. 

The pattern of declining infant mortality with increasing 

educational attainment characterized both major race groups. 

Table G. Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to mother’s marltal 

status; and mortality race ratios by mother’s marital status: United states, 1985 birth cohort 

Live births lnfsnt deaths Infant mortalify 

Race ratio 

Msritsl status All races White Black All races White Black All lxe.s White Black blackwhite 

Percent distribution Rate per 1,000 live births 

All mothers . . . . . . . . . . . 100.0 100.0 100.0 100.0 100.0 loo.0 10.4 8.9 18.3 2.06 

Married. . . . . . . . . . . . . . 78.0 85.5 39.9 64.7 77.6 32.9 8.6 8.0 15.1 1.83 

Not married . . . . . . . . . . . 22.0 14.5 60.1 35.3 22.4 67.1 16.7 13.7 20.5 1.50 

15 
25 

I 

Married Not Married Not Married Not 

married married married 

All races White Black 

Marital status 

Figure 7. Infant mortality rates by race of child and mother’s 

marital status: United States, 1999 birth cohort 

For the white population, mortality declined from 12.2 infant 

deaths per 1,000 live births to 6.3 as years of education 

increased from 8 or less to 16 or more (table II). For the black 

population, the corresponding decline in mortality was from 

17.5 to 14.6. While mortality decreased with increasing educational attainment, the race differential in mortality increased. 

The mortality race ratio increased horn 1.43 to 2.32 with 

increasing educational attainment of mothers. 

Trimester prenatal care began 

Compared with all live births, infants who died were 

somewhat less likely to have received prenatal care in the first 

trimester and somewhat more likely to have received late or 

no prenatal care. In the 1985 birth cohort, mothers initiated 

prenatal care during the first trimester for 76.3 percent of the 

live births and 69.2 percent of the infant deaths (table J). In 

contrast, mothers received no prenatal care or initiated care 

- 

0 

O-8 9-11 12 13-15 16 or 

more 

Years of education 

Figure 6. infant mortality rates by race of child and mother’s 

education: United States, 1965 birth cohort 

during the third trimester for 5.8 percent of the live births and 

11.3 percent of the infant deaths. 

Although only 1.7 percent of all mothers giving birth in 

1985 received no prenatal care, the infant mortality rate for 

those mothers (43.9 deaths per 1,000 live births) was 4.6 times 

the rate of 9.5 for other mothers who received care at any time 

during their pregnancy (table J, figure 9, and computed from 

data in table 8). There was little variation in infant mortality 

by trimester prenatal care began. 

The absence of association between trimester care began 

and infant mortality masks opposite patterns of association for 

neonatal and postneonatal mortality. For deaths in the neonatal 

period, there was a weak inverse relationship between neonatal mortality and trimester prenatal care began. Neonatal 

mortality decreased from 6.6 to 6.5 to 4.3 deaths per 1,000 live 

births as initiation of care was delayed from first to second to 

third trimester. Those infants who received no care experienced a substantially higher neonatal mortality rate of 32.8 per 

1,000 live births. 

For deaths in the postneonatal period, mortality was 

directly related to trimester prenatal care began. Postneonatal 

mortality increased from 3.0 to 5.0 to 6.0 deaths per 1,000 live 

births as initiation of care was delayed from first to second to 

Table H. Percent distribution of live births and Infant deaths and infant mortality rates by race of child, according to educational 

attainment for mothers 20 years of age and over; and mortality race ratios by mother’s education: United States, 1966 birth cohort 

Educational attainment 

Live births Infant deaths infant morta/ity 

Race ratio 

All races White Black All races White Black All races white Black black:white 

Percent distribution Rate per 1,000 live births 

All mothers 20 years of age 

and over . . . . . . . . . . . . lw.o 100.0 loo.0 lw.o 100.0 loo.0 9.9 8.4 18.3 2.16 

0-8y&XS.. . . . . . . . . . 2.8 2.5 2.9 3.6 3.7 2.8 12.8 12.2 17.5 1.43 

9-11 years . . . . . . . . 11.8 10.2 19.5 16.0 15.4 24.0 15.2 12.6 22.5 1.78 

12 years. . . . . . . . . . . . 43.8 43.5 46.5 45.2 45.2 45.9 10.2 8.7 18.0 2.07 

13-15 years . . . . . . . . . 22.6 22.8 21.8 19.8 19.9 19.8 8.7 7.3 16.6 2.27 

16 years and over. . . . . . 19.1 20.9 9.3 13.4 15.6 7.4 7.0 6.3 14.6 2.32 

NOTE Figures may not add to total due to rounding. 

16 
Table J. Percent distribution of live births and infant deaths and infant mortality rates by race of child, according to trimester prenatal 

care began; and mortality race ratios by trimester prenatal care began: United States, 1985 birth cohort 

Tdmester prenatal 

care began 

All mothers ............ 

First trimester. .......... 

Second trimester. ........ 

Third trimester and no care . . 

Third trimester. ........ 

No care ............. 

Live births Infant ds&h.s Infant moItaii?y 

Race ratio 

All rams White Black All races White Black All twes White Black black:tiite 

100.0 100.0 

76.3 79.8 

17.9 15.5 

5.8 4.7 

4.1 3.4 

1.7 1.3 

Percent distribution 

100.0 100.0 

61.2 69.2 

28.5 19.5 

10.3 11.3 

6.8 3.9 

3.5 7.4 

100.0 100.0 

74.4 58.0 

16.9 24.8 

8.7 17.1 

3.5 4.6 

5.1 12.6 

Rate per 1,000 Iii births 

10.4 8.9 18.3 

9.5 8.3 17.3 

11.3 9.6 16.2 

20.0 16.1 30.8 

10.1 9.2 12.6 

43.9 33.9 65.9 

2.06 

2.08 

1.69 

1.90 

1.37 

1.94 

NOTE Rgures may not add to total due to rounding. 

Infant ? 

Black 

65- 

, 

I 

60- I 

. 

, 

55 - I 

I 

. 50- . Neonatal l Black 

. . 

. I 

46- , 

E . . 

E 

i2 

40- . 

. z 

i% , 

9 35- . 

g 

H 

30.. 

25 - 

70 - 

20 - 

15 - 

10 - 

5 - 

0 I I I I I I I I I I I I 

1st 2d 3d No 1st 2d 3d No 1st 2d 3d No 

care care care 

Trimester prenatal care began 

Figure 9. Infant mortality rates by age at death, race of child, and trimester prenatal care began: United States, 1999 birth cohort 

third trimester. Postneonatal mortality was highest for infants nate measure, the Kessner index, defines care as “adequate,” 

who received no prenatal care (11.1). “intermediate,” and “inadequate” based on when prenatal 

The timing of the initiation of prenatal care is one care begins, the number of prenatal visits, and the gestational 

measure of the adequacy of prenatal care received. An alter- age of the infant (11). An analysis of birth outcomes in relation 

17 
to the Kessner index using the 1983 birth cohort national 

linked file found infant mortality rates for mothers receiving 

inadequate care to be 2.6 times that for mothers receiving 

adequate care (12). 

Detailed race 

The availability of national linked birth and infant death 

data offers an opportunity to evaluate race-specific period 

infant mortality rates published in vital Statistics @the United 

States, Volume II, MortuZity (VSUS) (13). Routinely published 

period rates for smaller minority race groups are generally 

understated because minority races are sometimes misreported 

as white on the death certificate (3). 

Inconsistencies in race identification at the time of an 

infant’s birth and death occur because of differences in 

reporting and processing race information from the birth and 

death c&tic&es. For the birth certificate, race of each parent 

is usually reported by the mother at the time of delivery and, 

for births described in this report, race of infant was coded 

according to rules that take account of the race of both parents 

(see Technical notes). For the death certificate, race of the 

deceased infant is reported by the funeral director based on 

information supplied by an informant, such as a parent, or 

based on observation; and race is coded directly as it was 

reported on the death certikate. 

Race-specik cohort infant mortality rates based on the 

national linked data set are more accurate than period rates, 

especially for minority race groups, because race information 

for both the numerator (infant deaths) and denominator (live 

births) is from the same source document, the birth certificate; 

and race is more accurately reported on the birth than death 

certificate. In contrast, race information for period rates is 

derived from two different source documents, the death certificate for the numerator and the birth certificate for the 

denominator. 

Differences between race-specific cohort and period rates 

come from three sources: 

the different reference periods of the numerators comprising the two rates (NOTE: The different reference periods 

of the numerators account for a difference of 3,117 events 

between the numerators of the cohort and period rates in 

the analysis that follows. Thus, a total of 117,120 infant 

deaths occurred to the combined birth cohorts of 1983-85; 

whereas, 120,237 infant deaths occurred to U.S. residents 

during the calendar years 1983-85.) (See Methods section.) 

the percent of infant deaths to the birth cohort that are 

linked in the linked file (See Methods section and table A.) 

the differences in reporting race on the birth and death 

certificates as described previously. 

Whereas the effect of the first two sources on cohort and 

period race-specific rates is obvious, the effect of the third 

source--differences in race-reporting between birth and death 

certificates-is more subtle and introduces systematic bias in 

period rates. The linked file is useful for evaluating the 

contriiution of race-reporting differences to this bias because 

it includes information from both the birth and death certificates. 

The evaluation was carried out using linked file data for 

the combined three birth cohorts of 1983-85 to improve 

stability of rates for smaller race groups. Race-specific (cohort 

rates in which the race variable for the numerator is based on 

the birth certificate (the cohort rates used throughout this 

report) are compared with “special” rates constructed fior this 

evaluation in which the race variable for the numerator is 

based on the death certikate (table K, columns 4 and 5). The 

difference between the race-spectic cohort and special rates is 

due specifically to differences in reporting race at the time of 

birth and death. Percent differences between race-specific 

cohort and special rates are estimates of the bias in Iperiod 

rates by detailed race that are published in the VSUS. Because 

Table K. Live births and infant deaths and mortality rates according to source of race Informatlon, and ratio of infant mortality rates by 

source of race information for detailed race groups: United States, 1983-85 birth cohorts 

infant deaths based on 

source of race information 

Infant mortality rates 

based on source of race 

information for infant death 

Live births Birth 1 Death * Birth 1 Death * 

Ratio of infant mortality 

rates by source 

of race iniormatiow 

Race birth:death certikate 

All races . . . . . . . . . . . . . . . . . . . . . . . 11,069,214 

Number 

117,120 117,120 

Rate per 1,000 live births 

10.6 10.6 1.00 

whlite ......................... 

Black ......................... 

American Indian or Alaskan native ....... 

Chinese ....................... 

Japanese ...................... 

Hawaiian. ...................... 

Filipino ........................ 

Other Asian or Pachic Islander ......... 

Other ......................... 

8,819,529 79,778 81,770 9.0 9.3 0.97 

1,787,X4 32,857 32,239 18.4 18.0 1.02 

126,682 1,649 1,183 13.1 9.4 1.39 

‘mm 347 284 7.2 5.5 1.31 

27,815 183 112 8.6 4.0 1.65 

21,767 236 198 10.8 9.1 1.19 

58,995 487 269 8.3 4.6 1.80 

173,239 1,505 1,050 8.7 6.1 1.43 

6,599 78 35 11.8 5.3 2.23 

‘FWX of child at birth bssed on ram of both parents as recorded on linked birth CS+WNXW 

*Race ofchild as recorded on tie death oortifioate. 

18 
special rates in this evaluation represent period rates, they are 

referred to as “period” rates in the discussion that follows. 

For the 1983-85 birth cohorts, the cohort infant mortality 

rate for the white population was 9.0 deaths per 1,000 live 

births, 3 percent lower than the period rate of 9.3 (table K). 

Period infant mortality rates for the white population slightly 

overstate mortality because infants of minority races tend to be 

reported as white on the death certticate. 

Cohort infant mortality rates for each of the minority 

races were higher than period rates by 2 percent for the black 

population to more than double for other races (table K). For 

the black population, the cohort rate was 18.4 infant deaths per 

1,000 live births, 2 percent higher than the period rate of 18.0. 

For other minority races, cohort rates were much higher than 

period rates. For example, for the Hawaiian population, the 

cohort rate of 10.8 infant deaths per 1,000 live births was 

19 percent higher; for Chinese, the cohort rate of 7.2 was 

31 percent higher; for the American Indian population, the 

cohort rate of 13.1 was 39 percent higher; for other Asian or 

Pacific Islanders, the cohort rate of 8.7 was 43 percent higher; 

for Japanese, the cohort rate of 6.6 was 65 percent higher; for 

the Filipino population, the cohort rate of 8.3 was 80 percent 

higher; and for other races, the cohort rate of 11.8 was 

123 percent higher. 

Compared with an infant mortality rate for the 1983-85 

birth cohorts of 9.0 deaths per 1,000 live births for the white 

population, mortality was lower for infants of the Japanese, 

Chinese, Filipino, and other Asian or PaciiIc Islander populations; whereas, mortality was higher for infants of the Hawaiian, other nonwhite, American Indian, and black populations 

(table K). 

19 
References 

1. Hogue CJR, Buehler JW, Strauss LT, Smith JC. Overview of the 

National Infant Mortality Surveillance (NIMS) project--design, 

methods, results. Public Health Rep 102(2):126-38. 1987. 

2. Chase HC. A study of infant mortality from linked records: 

Method of study and registration aspects. National Center for 

Health Statistics. Vital Health Stat 200. 1970. 

3. Frost F, Shy KK. Racial differences between linked birth and 

infant death records in Washington State. Am J Public Health 

70(9):974-6. 1980. 

4. Prager K, Flinchum GA, Johnson DP. The NCHS pilot project to 

link birth and infant death records: Stage 1. Public Health Rep 

102(2):21&23. 1987. 

5. Prager K. Evaluation of 1983-85 State and national linked files. 

In: Proceedings of the second evaluation meeting of the NCHS 

Linked Birth and Infant Death Record Project, IVl-22. Houston, Texas. 1989. 

6. National Center for Health Statistics. Vital statistics of the 

United States, 1985, vol I, natality, and vol II, mortality, part A. 

Technical appendix. Washington: Public Health Service. 1988. 

7. Moriyama IW, Greville TNE. Effect of changing birth rates upon 

infant mortality rates. Vital Statistics-Special Reports 19(21):401- 

12.1944. 

8. Guralnick L, Winter ED. A note on cohort infant mortality rates. 

Public Health Rep 80(8):692-4. 1965. 

9. National Center for Health Statistics. Advance report of final 

natality statistics, 1985. Monthly vital statistics report; ~0136 no 

4, suppl. Hyattsville, Maryland. Public Health Service. 1987. 

10. Wilcox A, Russell I. Why small black infants have a lower 

mortality rate than small white infants: The case for populationspec%c standards for birthweight. J Pediatr 116:7-10. 1990. 

11. Kessner DM, Singer J, Kalk CD, Schlesinger ER. Contrasts in 

health status, vol. 1. Infant death: An analysis by maternal risk 

and health care. Washington: Institute of Medicine, National 

Academy of Sciences. 1973. 

12. Offutt KB, Kochanek KD, MacDonnan MF, Prager K. The 

effect of prenatal care on birth outcomes: Birthweight and infant 

mortality. Presented at the annual meeting of the American 

Public Health Association. Chicago. 1989. 

13. National Center for Health Statistics. Vital statistics of the 

United States, 1985, vol II, mortality, part A, tables 2-4. 

Washington: Public Health Service. 1988. 

14. Berkov B. An evaluation of California’s inferred birth statistics 

for unmarried women. National Center for Health Statistics. 

Vital Health Stat 2(97). 1985. 

20 
List of detailed tables 

1. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, and birthweight: United States, 1985 

birthcohort................................... 

2. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, and gestational age: United States, 

1985birth cohort............................... 

3. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, and sex: United States, 1985 birth 

cohort....................................... 

4. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, and maternal age: United States, 

1985 birth cohort............................... 

5. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, maternal age, and live-birth order: 

United States, 1985 birth cohort. . . . . . . . . . . . . . . . . . . . 

6. Live births, infant deaths, and infant mortality rates, by age 

at death, race of child, and mother’s marital status: United 

22 States, 1985 birth cohort . . . . _ . . . . . . . . . . . . . . . . . . . . 29 

7. Live births, infant deaths, and infant mortality’rates, by age 

at death, race of child, mother’s age, and educational 

24 attainment: 47 States and the District of Columbia, 1985 

birthcohort................................... 30 

8. Live births, infant deaths, and infant mortality rates, by age 

25 at death, race of child, and month of pregnancy prenatal 

care began: United States, 1985 birth cohort. . . . . . . . . . . 32 

9. Live births, infant deaths, and infant mortality rates, by 

26 detailed race of child: United States, 1983,1984, and 1985 

birth cohorts.. . . . . . . . . . . . . _ _ . . . . . . . . . . . . . . . . . . 33 

27 

21 
k3 Table 1. Live births, infant deaths, and infant mortality rates, by age at death, race of child, and birthweight: United States, 1995 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; eady 

neonatal, 9-6 days: late neonatal, 7-27 days; and postneonatal, 28 days-ii months. Not stated birthweioht orooortionallv distributed for calculation of rates. Rates are per 1,000 live births.] 

Race and birthweight 

Live 

births 

Infant 

deaths 

Total 

neonatal 

Early 

neonatal 

Late 

neonatal 

Postneonatal 

Infant 

deaths 

Total 

neonatal 

Early 

neonatal 

Late 

neonatal 

Postneonatal 

All races’ ................. 

Less than 2,500 grams. ........ 

Lessthan 500 grams. ........ 

500-749grams ............ 

750-999grams ............ 

1,000-1,249grams .......... 

1,250-1,499grams. ......... 

1.500-1.999grams .......... 

2.000-2.499grams .......... 

2,500 grams or more .......... 

2.509-2.999gram.s. ......... 

3.0093,499grams .......... 

3.50&3,999gram.s .......... 

4,009-4,499 grams .......... 

4.50&4.999grams .......... 

5,000 grams or more. ........ 

Notstated. ................ 

White .................... 

Lessthan 2,500 grams. ........ 

Less than 500 grams. ........ 

50&749grams ............ 

750-999grams ............ 

1,009-1.249grams .......... 

1,2591,499 grams .......... 

1,500-1,999 grams .......... 

2.000-2,499grams .......... 

2,500 grams or more .......... 

2,500-2.999grams .......... 

3.000-3,499gram.s .......... 

3,500-3.999grams .......... 

4,000-4.499grams .......... 

4,50&4,999grams .......... 

5,OOOgrams or more. ........ 

Notstated ................. 

Black .................... 

Less than 2,500 grams. ........ 

Lessthan 500 grams. ........ 

500-749grams ............ 

750-999grams ............ 

l,OOO-1,249 grams. ......... 

1,2591,499grams .......... 

1,500-1,999grams .......... 

2,000-2,499 grams. ......... 

Number Rate 

3,760,833 39,146 25,573 21,317 4,256 13,572 10.4 6.8 5.7 1.1 3.6 

253,711 23,210 18,804 16,390 2,414 4,406 

4,860 4,341 4,311 4,258 53 30 

8,291 6,137 5655 5,175 480 482 

9,452 3,661 w35 5354 511 696 

10,578 1,964 1,489 1,148 343 475 

12,540 1,316 835 735 200 381 

48,402 2,544 1,656 1,277 379 888 

159,588 3,247 1,793 I.345 448 1,454 

3,502,342 14,807 5,720 3,934 1,786 9,087 

595,548 4,553 1,870 1,286 586 2,683 

1,378,114 5,734 2,079 1,399 680 3,655 

1,110,700 3,203 1,155 778 377 2,048 

345,358 958 382 267 115 576 

64,293 240 138 117 21 102 

8,329 119 96 88 8 23 

4,780 1,128 1,049 993 58 79 

94.5 77.1 67.5 9.6 17.4 

896.9 891.0 880.4 10.6 5.9 

747.6 691.0 634.2 56.7 56.6 

395.3 322.3 268.3 54.0 73.0 

190.2 145.4 112.7 32.6 44.9 

107.7 77.3 61.2 16.1 30.4 

53.9 35.5 27.6 7.9 18.4 

20.8 11.7 8.8 2.8 9.2 

4.3 1.7 1.2 0.5 2.6 

7.8 3.3 2.3 1.0 4.5 

4.2 1.6 1.1 0.5 2.7 

2.9 1.1 0.7 0.3 1.9 

2.8 1.1 0.8 0.3 1.7 

3.8 2.2 1.9 0.3 1.8 

14.8 12.0 11.1 * 2.8 

. . . . . . . . . . . 

2,991,521 26,526 17,381 14,323 3,058 9,145 8.9 5.8 4.8 1.0 3.1 

168,478 14,959 12,368 10,699 1,669 2,591 

2,747 2,485 2,447 2,414 33 18 

4,863 3,683 3,458 3,177 279 227 

5,734 2,402 2,036 1,681 355 386 

6,755 1,390 1,118 873 245 272 

8,026 948 710 550 160 238 

32,057 1,807 1,257 978 279 550 

108,296 2,284 1,344 1,026 318 920 

2,819,384 10,857 4,356 3,012 1,344 8,501 

421,418 3,145 1,371 958 413 1,774 

1,079,510 4,171 1,583 1,079 504 2,588 

945,835 2,487 918 616 302 1,569 

307,164 779 315 216 99 464 

58,046 193 104 86 18 89 

7,391 82 65 57 8 17 

3,679 710 657 612 45 53 

91.5 76.1 66.1 10.0 15.4 

900.3 894.0 882.3 11.7 t 

763.7 718.2 661.7 56.5 45.5 

426.7 383.5 301.6 81.9 63.2 

210.7 170.5 134.0 38.5 40.2 

121.1 91.4 71.3 20.1 29.7 

57.8 40.8 31.8 8.8 17.2 

21.4 12.9 9.9 3.0 8.5 

3.9 1.6 1.1 0.5 2.3 

7.8 3.4 2.4 1.0 4.2 

3.9 1.5 1.0 0.5 2.4 

2.7 1.0 0.7 0.3 1.7 

2.8 1.1 0.7 0.3 1.5 

3.4 1.9 1.5 * 1.5 

11.5 9.1 8.0 * * 

. . . . . . . . * . . . . . 

808,309 11,140 7,339 6,294 1,045 3,801 18.3 12.1 10.3 1.7 6.2 

75,482 7,476 5,832 5,172 680 1,644 102.7 80.9 72.1 8.8 21.8 

1,972 1,747 1,735 1,718 17 12 890.7 884.9 876.6 l * 

3,197 2,282 2,039 1,856 183 243 722.7 648.9 593.2 55.7 73.8 

3,444 1,146 842 898 144 304 340.7 253.1 211.8 41.6 87.6 

3,464 491 308 221 87 183 145.2 92.3 67.2 25.2 52.9 

4,099 320 190 156 34 130 80.2 48.5 40.1 8.3 31.8 

14,598 845 341 255 86 304 46.3 24.4 18.4 5.9 20.9 

44,??0 845 377 268 189 468 19.3 8.8 6.3 2.5 10.5 
2.5OOgramsormore .......... 

2,500-2,999 grams .......... 

3,000-3,498 grams. ......... 

3,500-3,999 grams. ......... 

4,000-4,498 grams. ......... 

4,500-4,999 grams. ......... 

5,000 grams or more ......... 

Not stated ................. 

531,968 3,291 1,155 778 

143,378 1,225 433 286 

232,934 1,293 414 260 

123,198 580 185 129 

27,436 144 62 50 

4,374 34 26 23 

648 3s 30 30 

859 373 352 344 

377 

152 

154 

56 

12 

3 

8 

2,136 

787 

879 

375 

82 

8 

5 

21 

6.3 2.3 1.5 

8.7 3.2 2.1 

5.6 1.8 1.2 

4.6 1.6 1.1 

5.4 2.4 1.9 

8.1 6.2 5.6 

56.5 48.8 48.8 

. . . . . . . . . 

0.7 

1.1 

0.7 

0.5 

* 

* 

* 

. . . 

4.0 

5.5 

3.8 

3.1 

3.0 

* 

l 

. . . 

‘Includes races other than white snd black 
P Table 2. Live births, infant deaths, and infant mortality rates, by age at death, race of child, and gestational age: United States, 1985 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, 96 days; late neonatal, 7-27 days; and postneonatal. 28 days11 months. Not stated gestational age proportionally distributed for calculation of rates. Rates are per 1,000 live births.] 

Race and gestational age 

Lb 

births 

Infant 

deaths 

Total 

neonatal 

Ear/y 

neonatal 

Late 

neonatal 

Postneonatal 

Want 

deaths 

Total 

neonatal 

Early 

neonatal 

Late 

neonatal 

Postneonatal 

All races’ . . . . . 

Less than 28 weeks. 

28-31 weeks . . . . . 

32-35 weeks . . . . . 

36 weeks. . . . . 

3739 weeks . . . 

40 weeks. . . . . . . . 

41 weeks. . . . . . . . 

42 weeks or more . . 

Not stated . . . . . . . 

White . . . . . . . . . . 

Less than 28 weeks. 

28-31 weeks . . . . . 

32-35 weeks . . . . . 

36 weeks. . . 

3739 weeks . . 

40 weeks. . . . . . . 

41 weeks. . . . . . . . 

42 weeks or more . . 

Not stated . . . . . . . 

Black . . . . . . . . . . 

Less than 28 weeks. 

28-31 weeks . . . . . 

32-35 weeks . . . . . 

36 weeks. . . . . . . . 

3739 weeks . . . 

40 weeks. . . . . . . 

41 weeks. . . . . . . . 

42 weeks or more . . 

Not stated . . . . 

. . . . . . 

. . . . . . 

. . . . . . 

. ..*.* 

. . . . . . 

. . . . . . 

. . . . . . 

. . . . . . 

. . 

. . 

. . 

. . 

. * 

. . . . . . 

. . 

. . 

. 

. . . . . . 

. . . . . 

. . . . . . 

3,760,833 39,145 25,573 21,317 

27,658 11,672 10,686 9,832 

40,373 3,581 2,646 2,078 

168,271 3,574 2,257 1,899 

116,806 1,313 706 539 

1,409,196 7,227 2,986 2,055 

797,930 3,085 1,223 850 

651,067 2,162 997 638 

513,233 2,897 1,181 881 

145,389 3,854 2,981 2,657 

2,991,521 28,526 17,381 14,323 

15,997 7,095 @A590 6,039 

24,808 2,446 1,891 1,477 

111,827 2,525 1,726 1,393 

83.444 916 529 415 

I.092654 5,166 2,232 1,567 

661,215 2,247 895 614 

467,404 1,645 708 496 

423,786 2,034 908 648 

110,386 2,452 1,902 1,674 

698,309 11,140 7,339 6,294 

10,835 4,247 3,793 3,519 

14,056 985 661 527 

48,707 901 454 362 

28,094 348 149 102 

241,498 1,727 633 411 

104,336 702 276 197 

64,105 431 173 119 

70,648 556 235 188 

26,030 1,243 965 881 

4,256 13,572 

854 986 

568 915 

448 1,317 

167 607 

931 4,241 

373 1,882 

271 1,255 

320 1,516 

324 873 

3,058 9,145 

551 505 

414 555 

333 799 

114 387 

665 2,934 

281 1,352 

212 937 

260 1,126 

228 550 

1,045 3,801 

274 454 

134 324 

102 447 

47 199 

222 1,094 

79 426 

54 258 

49 321 

84 278 

10.4 8.8 5.7 1.1 3.6 

435.4 400.7 370.2 30.4 34.8 

93.5 70.4 55.9 14.5 23.1 

22.6 14.5 11.8 2.8 8.0 

11.9 6.5 5.1 1.5 5.3 

5.4 2.3 1.6 0.7 3.1 

4.1 1.7 1.2 0.5 2.4 

4.1 1.8 1.3 0.5 2.3 

5.5 2.5 1.8 0.6 3.0 

. . . . . . . . . . . . . 

8.9 5.8 4.8 1.0 3.1 

455.4 424.7 390.7 34.0 30.7 

104.2 81.5 64.3 17.2 22.7 

24.0 16.7 13.6 3.1 7.3 

11.6 8.8 5.4 1.4 4.8 

5.0 2.2 1.6 0.6 2.8 

3.6 1.5 1.0 0.4 2.1 

3.7 1.8 1.2 0.5 2.1 

5.0 2.3 1.7 0.6 2.7 

. . . . . . . . . . . 

18.3 12.1 10.3 1.7 8.2 

408.2 367.2 342.3 24.9 41 .o 

75.0 51.3 41.5 9.9 23.6 

19.7 10.2 8.0 2.2 9.5 

13.1 5.8 4.0 1.7 7.3 

7.5 2.9 1.9 1 .o 4.7 

7.1 2.9 2.1 0.8 4.2 

7.1 2.9 2.1 0.9 4.2 

8.4 3.7 2.9 0.7 4.7 

. . . . . . . . . . . . 

flncludes races other than white and black. 
Table 3. Live births, infant deaths, and infant mortalfty rates, by age at death, race of child, and sex: United States, 1995 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race according to race reported on the matching birth cettiicate. infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early neonatal 

O-6 days: late neonatal, 7-27 days: and postneonatal, 28 days-11 months. Rates are per 1,000 live births.] 

Lb8 Infant Total E&v/y ht8 Posf- infmt Total Ear/y ht8 PosfRace and sex births deaths neonatal mwnatai neonatal neonatal deaths neonatal neonatal monatal neonatai 

Number Rate 

All races’ . . . . . . . . . . . . . . . . . 3,760,833 39,145 25,573 21,317 4,256 13,672 10.4 6.8 5.7 1.1 3.6 

Male . . . . . . . . . . . . . . . . ; . . . 1,928,138 22,466 14,604 12,182 2,422 7,862 11.7 7.6 6.3 1.3 4.1 

Female. . . . . . . . . . . . . . . . . . . 1,832,6Q5 16,679 10,969 9,135 1,834 5,710 9.1 6.0 5.0 1.0 3.1 

White.................... 2,991,521 26,526 17,381 14,323 3,056 9,145 8.9 5.8 4.8 1 .o 3.1 

Male . . . . . . . . . . . . . . . . . . . . 1,536,72Q 15,446 10,044 8,261 1,783 5,402 10.1 6.5 5.4 1.2 3.5 

Female................... 1,454,792 11,080 7,337 6,062 1,275 3,743 7.8 5.0 4.2 0.9 2.6 

Black . . . . . . . . . . . . . . . . . . . . 608,309 11,140 7,339 6,294 1,045 3,801 18.3 12.1 10.3 1.7 6.2 

Male . . . . . . . . . . . . . . . . . . . . 308,643 6,161 4,066 3,516 549 2,096 20.0 13.2 11.4 1.8 6.8 

Female................... 299,666 4,979 3,274 2,778 498 1,705 16.6 10.9 9.3 1.7 5.7 

llncludes races other than white and black. 
ti Table 4. Live births, infant deaths, and infant mortality rates, by age at death, race of child, and maternal age: United States, 1985 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certiicate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, 6-6 days; late neonatal, 7-27 days; and postneonatal, 28 days-11 months. Rates are per 1,006 live births.] 

Race and maternal age 

Live infant Total Ear/y kt8 Post- infant Total Ear/y iAt Postbirths deaths neonatal neonatal neonatal neonatal deaths neonatal neonatal neonatal neonatal 

Number Rate 

All races’ ................. 

Under15years .............. 

15-19years ................ 

15-17years.. ............ 

1819years .............. 

20-24years ................ 

25-29years ................ 

3634years ................ 

3539years ................ 

40-44 years. ............... 

45-49yeam ................ 

Whtte .................... 

Under15years .............. 

15-19 years. ............... 

15-17years .............. 

16-IQyears .............. 

20-24years ................ 

25-29years ................ 

30-34 years. ............... 

35-39years ................ 

4644years ................ 

45-49years ................ 

Black .................... 

Under15years .............. 

15-19years ................ 

1517years .............. 

18-19years .............. 

26-24years ................ 

25-29years ................ 

30-34years ................ 

35-39years ................ 

46-44years ................ 

45-49years ................ 

3.760833 39,145 25,573 21,317 

10,223 225 151 122 

467,519 6,999 4,218 3,540 

167,808 2,777 1,703 1,448 

299,711 4,222 2,515 2,092 

1,141,386 12,841 7,846 6,496 

1,201,452 10,578 7,265 6,103 

696,408 5,991 4,326 3,589 

214,348 2,132 1,521 1,261 

28,335 352 229 193 

1,162 27 17 13 

2,991,521 26,526 17,381 14,323 

4,102 8-5 56 46 

318,738 4,150 2,507 2,067 

106,049 1,516 942 788 

212,689 2,634 1,565 1,279 

894,231 8,610 5,187 4,253 

997,284 7,528 5,195 4,313 

580,433 4,376 3,172 2.@33 

173,692 1,520 1,099 962 

22,265 240 153 127 

776 17 12 9 

608,309 11,140 7,339 6,294 

5,862 139 95 76 

134,290 2,652 1,605 1,389 

56,821 1,180 715 625 

77,469 1,472 696 764 

207,359 3,800 2,443 2,866 

152,352 2,642 1,810 1,574 

78,147 1,341 992 653 

26,217 483 337 288 

3,888 77 53 45 

194 6 4 3 

4,256 13,572 10.4 6.8 5.7 1.1 3.6 

29 74 22.0 14.8 11.9 2.8 7.2 

678 2,781 15.0 9.0 7.6 1.5 5.9 

255 1,074 16.5 10.1 8.6 1.5 6.4 

423 1,707 14.1 8.4 7.0 1.4 5.7 

1,356 4,995 11.3 6.9 5.7 1.2 4.4 

1,162 3,313 8.8 6.0 5.1 1.0 2.8 

737 1,665 8.6 6.2 5.2 1.1 2.4 

260 611 9.9 7.1 5.9 1.2 2.9 

36 123 12.4 8.1 6.8 1.3 4.3 

4 10 23.2 t l * * 

3,058 9,145 8.9 5.8 4.8 1.0 3.1 

10 29 20.7 13.7 11.2 2.4 7.1 

440 1,643 13.0 7.9 6.5 1.4 5.2 

154 574 14.3 8.9 7.4 1.5 5.4 

286 1,069 12.4 7.4 6.0 1.3 5.0 

934 3,423 9.6 5.8 4.8 1.0 3.8 

882 2,333 7.5 5.2 4.3 0.9 2.3 

566 1,204 7.5 5.5 4.5 1.0 2.1 

197 421 8.8 6.3 5.2 1.1 2.4 

26 87 10.8 6.9 5.7 1.2 3.9 

3 5 * * * * l 

1,045 3,801 18.3 12.1 10.3 1.7 6.2 

19 44 23.7 16.2 13.0 * 7.5 

216 1,047 19.7 12.0 10.3 1.6 7.8 

90 465 20.8 12.6 11.0 1.6 8.2 

126 582 19.0 11.5 9.9 1.6 7.5 

377 1,357 18.3 11.8 10.0 1.8 6.5 

236 632 17.3 11.9 10.3 1.5 5.5 

139 349 17.2 12.7 10.9 1.8 4.5 

49 146 18.4 12.9 11.0 1.9 5.6 

8 24 19.8 13.6 11.6 * 6.2 

1 2 * * * * t 

'Includes races otherthanwhiieand black. 
Table 5. Live births, infant deaths, and infant mortality rates, by age at death, race of child, maternal age and live-birth order: United States, 1955 birth cohort 

wve births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certikate. Infant deaths are under 1 year of age. Neonatal deaths are under28 days; early 

neonatal, O-6 days; late neonatat,7-27 days; and postneonatal, 28 days-11 months. Not stated live birth order proportionally distributed for calculation of rates. Rates are per 1,000 live births.] 

Race, matemai age, Live infant Total Earth Late Posf- infant Total Earlv tblt8 postand live-birth onfef births deaths neonatal neonatai neonatal neonatai deaths neonatal neonatal neonatal neonatal 

All races’ Number Rate 

Mothers ofail ages ........... 

First child ................ 

Secondchild .............. 

Third child ................ 

Fourthchildand over. ........ 

Notstated ................ 

Mothers under20 years of age .... 

First child ................ 

Secondchild .............. 

Thirdchild. ............... 

Fourthchildandover. ........ 

Not stated ................ 

Mothers 20-34 years of age. ..... 

First child ................ 

Secondchild .............. 

Thirdchild ................ 

Fourthchildandover ......... 

Notstated ................ 

Mothers 35-49years of age. ..... 

First child ................ 

Secondchild .............. 

Thirdchild ................ 

Fourthchildandover ......... 

Notstated ................ 

White 

Mothersofall ages ........... 

First child ................ 

Second child .............. 

Thirdchild. ............... 

Fourthchitdandover. ........ 

Notstated ................ 

Mothers under20 years of age .... 

First child ................ 

Secondchild .............. 

Thirdchild. ............... 

Fourthchildandover. ........ 

Notstated ................ 

Mothers 26-34yearsofage. .. 

First child ............. 

Secondchild ........... 

Third child. ............ 

Fourthchildandover ...... 

Notstated ............. 

3.760633 39,145 25,573 21,317 4,256 13,572 

1554,676 15,393 10,736 9,010 1,726 4,657 

1,242,205 12,047 7,534 6,216 1,318 4,513 

584,541 6,332 3,942 3,300 642 2,390 

356,562 4,798 2,885 2,346 539 1,913 

22,649 575 476 445 31 99 

477,742 7,224 4,369 3,662 707 2,855 

369,145 4,852 3,096 2,590 506 1,756 

87,560 1,784 947 794 153 837 

15,527 421 209 167 42 212 

2434 80 46 43 3 34 

3,076 87 71 68 3 16 

3,039,246 29,410 19,437 16,188 3,249 9,973 

1,142,376 10,054 7,277 6,114 1,163 2,777 

1,089,014 9,685 6,181 5,089 1,092 3,504 

513,591 5,392 3,374 z830 544 2,018 

276,377 3,837 z238 1,815 423 1,599 

17,888 442 367 340 27 75 

243,845 2,511 1,767 1,467 300 744 

a= 487 363 306 57 124 

65,631 578 406 333 73 172 

55,423 519 359 308 58 160 

77,751 881 601 486 113 260 

1,685 46 38 37 1 8 

2,9Q1,521 26,526 17,361 14,323 3,058 9,145 

1,252,OQ6 10,739 7,432 6,197 1,285 3,257 

1,011,369 f3,53C’ 5,315 4,336 979 3,215 

457,220 4,115 2,582 2,131 451 1,533 

251,975 2,731 1,673 1,= 318 1,056 

18,861 411 329 804 25 62 

322,840 4,235 z333 2,113 460 1,672 

256,654 2,973 1,886 1,553 333 1,087 

54,924 999 527 484 93 472 

7,913 178 87 66 21 91 

941 21 12 11 1 9 

2,208 64 51 49 2 13 

2,471,948 20,514 13,554 11,172 2,382 6,960 

958,998 7,415 5,330 4,422 908 2,065 

902,122 7,066 4,470 3,646 824 2,618 

403,976 3,562 2,238 1,855 383 1,324 

191,607 2,136 1,266 1,021 245 870 

15,245 313 250 228 22 63 

10.4 

10.0 

9.8 

10.9 

13.6 

. . . 

15.1 

13.2 

20.5 

27.2 

33.0 

. . . 

9.7 

8.9 

9.0 

10.6 

14.0 

. . . 

10.3 

11.4 

8.9 

9.5 

11.5 

. . . 

6.8 5.7 

7.0 5.9 

6.1 5.1 

6.6 5.7 

8.2 6.7 

*.. . . . 

9.1 7.7 

8.5 7.1 

10.9 9.2 

13.6 10.9 

19.1 17.8 

. . . . . . 

6.4 5.3 

8.5 5.4 

5.8 4.7 

6.7 5.6 

8.2 6.7 

. . . . . . 

7.2 6.0 

8.5 7.2 

6.3 5.2 

6.6 5.6 

7.8 6.4 

. . . . . . 

8.9 5.8 

6.7 6.1 

8.5 5.3 

9.1 5.7 

10.9 6.7 

. . . . . . 

13.1 7.9 

11.7 7.4 

18.3 9.7 

22.6 11.1 

22.5 * 

. . . . . . 

8.3 5.5 

7.8 5.6 

7.9 5.0 

8.9 5.6 

11.2 6.7 

. . . . . . 

4.6 

5.0 

4.4 

4.7 

5.5 

. . . 

6.5 

6.1 

8.0 

8.5 

* 

. . . 

4.5 

4.7 

4.1 

4.7 

5.4 

. . . 

1.1 

1.1 

1.1 

1.1 

1.5 

. . . 

1.5 

1.4 

1.7 

2.7 

* 

. . . 

1.1 

1.0 

1.0 

1.1 

1.5 

. . . 

1.2 

1.3 

1.1 

1.0 

1.4 

. . . 

3.6 

3.0 

3.6 

4.1 

5.4 

. . . 

6.0 

4.8 

9.6 

13.6 

13.9 

. . . 

3.3 

2.4 

3.2 

3.9 

5.8 

. . . 

3.1 

2.9 

2.6 

2.9 

3.6 

. . . 

1.0 3.1 

1.0 2.6 

1.0 3.2 

1.0 3.4 

1.3 4.2 

. . . . . . 

1.4 5.2 

1.3 4.2 

1.7 8.6 

2.6 11.5 

* * 

. . . 

1.0 

0.9 

0.9 

1.0 

1.3 

. . . 

* . . 

2.8 

2.2 

2.9 

3.3 

4.6 

. . . 
ti Table 5. Live births, infant deaths, and infant mortality rates, by age at death, race of child, maternal age and live-birth order: United States, 1955 birth cohort-Con. 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under28 days; early 

neonatal, O-6 days; late neonatal, 7-27 days; and postneonatal, 28 days-11 months. Not stated live birth order proportionally distributed for calculation of rates. Rates are per 1,000 live births.] 

Race, maternal age, Lhf8 infant Total Eariy .kt8 Post- infent Total Ear/y kIt8 Postand iive-birth order births deaths neonatal neonatal neonatal neonatal deaths neonatal neonatal neonatal neonatal 

White-Con. Number Rate 

Mothers 35-49 yearsofage. ..... 

Firstchild ................ 

Secondchild .............. 

Third child ................ 

Fourthchildandover ......... 

Notstated ................ 

Black 

196,733 1,777 1,264 1,038 226 513 

36,244 351 266 222 44 65 

54,323 443 318 256 62 125 

45,331 375 257 210 47 118 

59,427 574 395 323 72 179 

1,406 34 28 27 1 6 

9.0 6.4 5.3 1.1 2.6 

9.8 7.5 6.2 1.2 2.4 

8.3 5.9 4.8 1.1 2.3 

8.4 5.8 4.7 1.0 2.6 

9.8 6.7 5.5 1.2 3.0 

. . . . . . . . . . * . ..* 

Mothers of all ages ........... 

First child ................ 

Secondchild .............. 

Thirdchild ................ 

Fourthchitdand over. ........ 

Notstated ................ 

Mothers under20 years of age .... 

Fir&child ................ 

Secondchild .............. 

Thirdchild. ............... 

Fourthchitdandover. ........ 

Notstated ................ 

Mothers2634yearsofage ...... 

First child ................ 

Secondchild .............. 

Thirdchild. ............... 

Fourthchildandover ......... 

Not stated. ............... 

Mothers35-49yearsofage ...... 

Firstchild ................ 

Secondchild .............. 

Thirdchild ................ 

Fourthchitdand over. ........ 

Notstated ................ 

608,309 11,140 7,339 6,294 1,045 3,801 

238,712 4,133 2,931 2,547 384 1,202 

180,280 3,090 1,984 1,690 294 1,168 

102,726 1,949 1,215 1,043 172 734 

83,703 1,825 1,082 892 190 743 

2,888 143 127 122 5 16 

140,152 2,791 1,7M) 1,465 235 1,091 

101,279 1,759 1,137 980 157 622 

29,709 728 396 341 55 332 

7,017 225 116 98 20 109 

1,379 58 33 31 2 25 

768 21 18 17 1 3 

437,858 7,783 5,245 4,493 752 2,538 

133,641 2,270 1,718 1,500 218 552 

144,088 2,264 1,521 1,290 231 743 

89,144 1,610 1,019 875 144 591 

69,161 1,525 885 730 156 640 

1,924 114 102 98 4 12 

30,299 566 394 336 

3,892 104 76 67 

6,483 98 67 59 

6,565 114 80 72 

13,163 242 164 131 

196 8 7 7 

58 

9 

8 

8 

38 

172 

28 

31 

34 

78 

1 

18.3 12.1 10.3 1.7 6.2 

17.4 12.4 10.8 1.6 5.0 

17.3 11.2 9.5 1.6 6.1 

19.1 12.0 10.3 1.7 7.1 

22.0 13.1 10.8 2.3 8.9 

* * * . . . . . . . . . . . 

19.9 12.1 10.5 1.7 7.8 

17.4 11.3 9.7 1.5 6.1 

24.5 13.4 11.5 1.8 11.1 

32.1 16.6 13.8 2.8 15.5 

42.1 24.1 22.6 * 18.1 

. . . . . . . . . . ..* 

17.8 12.0 10.3 1.7 5.8 

17.2 13.1 11.4 1.6 4.1 

15.9 10.7 9.1 1.6 5.2 

18.2 11.6 10.0 1.6 6.6 

22.2 13.0 10.7 2.2 9.3 

. . . . . . . . . . . . . . . 

18.7 13.0 11.1 1.9 5.7 

27.0 19.8 17.5 * 7.2 

15.2 10.5 9.2 * 4.8 

17.5 12.3 11.1 l 5.2 

18.5 12.6 10.1 2.5 5.9 

. . . . . . . . . . . . . . . 

llncludesracesotharthanwhiteand black. 
Table 6. Live births, Infant deaths, and infant mortality rates, by age at death, race of child, and mother’s marital status: United States, 1966 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, O-6 days; late neonatal, 7-27 days; and postneonatal, 28 days-11 months. Rates are per 1,000 live births.] 

infant Total Earfy /St8 Post 

b% 

infant 

Race and marital status deaths 

Total E&Y ht8 postn8onatfzl n8onatai n8onatal n8onafai dsaths neonatal neonatal neonatal neonafal 

Number Rate 

All races’ . . . . . . . * . . . . . . . . . 3,760,633 39,145 25,573 21,317 4,256 13,572 10.4 6.8 5.7 1.1 3.6 

Married. . . . . . . . . . . . . . . . . . . 2,Q32,562 25,321 16,965 14,014 2,951 8,356 8.6 5.8 4.8 1.0 

Unmarried . . . . . . . . . . . . . . . . . 828,271 

2.8 

13,824 W’J3 7,303 1,305 5,216 16.7 10.4 8.8 1.6 6.3 

White . . . . . . . . . . . . . . . . . . . . 2,QQl,521 26,526 17,381 14,323 3,058 9,145 8.9 5.8 4.8 1.0 3.1 

Married. . . . . . . . . . . . . . . . . . . 2,666,522 20,692 13,756 11,284 2,472 6,836 8.0 5.4 4.4 1.0 

Unmarried . . . . . . . . . . . . . . . , . 432,999 

2.7 

5,934 3,625 3,039 586 2,309 13.7 8.4 7.0 1.4 5.3 

Black.................... 6of.wJQ 11,146 7,339 WQ4 1,045 3,801 18.3 12.1 10.3 1.7 6.2 

Married. . . . . . . . . . . . . . . . . . . 242,717 3,663 z5@3 2,208 363 1,094 15.1 10.6 9.1 1.5 

Unmarried . . . . . . . . . . . . . . . . . 365,592 

4.5 

7,477 4,770 4,066 682 2,707 20.5 13.0 11.2 1.9 7.4 

‘Indudes raw other than white and black. 
8 Table 7. Live births, infant deaths, and infant mortality rates, by age at death, race of child, mother’s age, and educational attainment: 47 States and the District of Columbia, 1985 

birth cohort 

[Live births and infant deaths are by State of residence at birth. Race Is according to race reported on the matching birth certiffcate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, O-6 days; late neonatal, 7-27 days; and postneonatal, 28 days-11 months. Not stated education proportionally distributed for calculation of rates. Rates are per 1,000 live births.] 

RaC8, mother’s age, Live infant Total Early Late Post- infant Total Eariy k!t8 Postand educational attainment births deaths neonatal neonatal neonatal neonatal deaths naonatai neonatal neonatal neonatal 

Mothers of all ages Number Rate 

Allraces' ................. 

o-ayears ................. 

9-11 years ................. 

12years .................. 

13-15years ................ 

16yearsormore ............. 

Not stated ................. 

Whtte .................... 

tHyears ................. 

Q-11 years ................. 

12yeaffi .................. 

13-15yeam ................ 

16yearsormore. ............ 

Notstated ................. 

Black .................... 

6-8years ................. 

Q-11 years ................. 

12 years. ................. 

13-15years ................ 

16yearsormore ............. 

Notstated ................. 

Mothers under20years of age 

Alraces' ................. 

0-8years ................. 

Q-11 years ................. 

12years .................. 

X3-15years ................ 

16yearsormore ............. 

Notstated ................. 

White .................... 

0-8years ................. 

9-11 years ................. 

12years .................. 

13-15years ................ 

16yearsormore. ............ 

Notstated ................. 

2.911,422 31,120 20,602 17,282 3,320 10,518 

102,603 1,537 915 724 191 622 

487,902 7,553 4,279 3,528 751 3,274 

1220,686 12,507 8,355 6,997 1,358 4,152 

576,814 4,903 3,463 2,923 560 1,420 

478,870 3,226 2,387 2,ooo 387 a39 

44,547 1,394 1,183 1,110 73 211 

2299,167 20,517 13,613 

73,092 1,002 589 

329,286 4,300 2,452 

967,887 8,366 5,547 

471,504 3,348 2,353 

423,712 2,600 1,913 

33,686 901 759 

11,290 2,323 6,904 

456 133 413 

2,m 452 1,848 

4,598 949 2,819 

1,945 408 995 

1,583 330 687 

708 51 142 

517,097 

22,102 

142,445 

219,401 

89,089 

36,260 

7,820 

9,700 6,477 5,565 912 3,223 

454 276 226 50 178 

3,030 1,723 1,446 277 1,307 

3,833 2,632 2,251 381 1,201 

1,425 1,055 913 142 370 

508 396 351 45 112 

450 395 376 17 55 

10.7 7.1 

15.4 9.3 

15.9 9.2 

10.6 7.2 

a.8 6.3 

7.0 5.2 

. * * * * . 

8.9 5.9 

14.1 a.4 

13.4 7.8 

8.9 8.0 

7.3 5.2 

6.3 4.7 

. . . . . . 

18.8 12.5 

21.1 13.0 

21.8 12.7 

la.1 12.6 

16.6 12.4 

14.6 11.5 

. . 9 . . . 

5.9 1.1 

7.4 1.9 

7.6 1.5 

6.0 1.1 

5.3 1.0 

4.4 0.8 

. . * . . * 

4.9 1.0 

6.6 1.8 

6.4 1.4 

5.0 1.0 

4.3 0.9 

3.9 0.8 

. . . . . 

10.8 1.8 

10.8 2.3 

10.7 2.0 

10.8 1.7 

10.8 1.6 

10.2 1.2 

. . . . . . 

372,196 5,901 3,591 3,019 

33,344 675 389 316 

193,895 3,204 1,822 1,510 

126,259 1,644 1,070 904 

12,590 138 103 90 

102 1 1 1 

6,686 239 266 198 

572 2,310 

73 286 

312 1,382 

166 574 

13 35 

15.9 9.6 8.1 1.5 6.2 

20.7 12.2 10.0 2.2 8.6 

16.9 9.8 8.2 1.6 7.1 

13.4 8.9 7.5 1.3 4.5 

11.3 8.5 7.5 * 2.8 

10.4 * * * l 

240,288 

21,590 

122,081 

84,582 

8,051 

73 

3,911 

3,289 2,~ 1,659 

391 224 179 

1,762 1,010 824 

929 593 497 

69 54 43 

1 1 1 

137 118 115 

a 

341 

45 

186 

96 

11 

- 

3 

33 

1,289 

167 

752 

336 

15 

19 

. . . 

13.7 

18.6 

14.8 

11.3 

a.9 

l 

* . . 

. . . . . . 

8.3 6.9 

10.8 8.8 

8.6 7.1 

7.3 6.2 

7.0 5.6 

* * 

. . . . . . 

. . 

1.4 

2.1 

1.5 

1.1 

* 

* 

. . . 

3.6 

6.1 

6.7 

3.4 

2.5 

1.8 

* . . 

3.0 

5.7 

5.6 

2.9 

2.1 

1.6 

. . . 

6.2 

6.0 

9.2 

5.5 

4.2 

3.1 

. . . 

. . . 

5.4 

7.7 

6.2 

4.0 

* 

* 

. . . 
Black .................... 

0-8yeaffi ................ 

Q-11 years ................ 

12years ................. 

13-15years ............... 

16yearsormore ............ 

Notstated ................ 

Mothersage20yearsandover 

All races' ................. 

0-8years.. ............... 

Q-11 yean ................. 

12years .................. 

13-15yeaffi ................ 

16yearsormore ............. 

Notstated ................. 

Whiie .................... 

0-6years...... 

Q-11 years...... 

12years....... 

13-15years..... 

16 years or more. . 

Not stated . . . . . . 

. . . . . . . . . . 

......... 

......... 

......... 

Black .................... 

Myears ................. 

Q-llyears ................. 

12years .................. 

13-15years ................ 

16yearsormore ............. 

Notstated ................. 

121,517 

10,688 

66,537 

w= 

4,155 

21 

1,751 

2,539,226 25,219 17,011 14,263 2,748 8,208 

69,259 862 526 408 118 336 

294,007 4,349 2,457 2,018 439 1,892 

l,OQ4,427 10,863 7,285 6,093 1,192 3,578 

564,224 4,765 3,380 2,833 547 1,385 

478,768 3,225 2,386 1,999 387 839 

38,541 1,155 977 912 65 178 

2,058,879 17,228 11,613 9,631 

51,502 611 365 277 

207,205 2,538 1,442 1,176 

883,305 7,437 4,954 4,101 

463,453 3,279 2,299 1,902 

423,639 2,599 1,912 1,582 

29,775 764 641 593 

1,982 5,615 

aa 246 

266 1,096 

853 2,483 

397 980 

330 687 

48 123 

395,560 

11,414 

75,908 

tat,036 

64,914 

36,239 

‘3339 

7,228 898 

193 

1,661 

3,150 

1,359 

508 

357 

4,960 4,262 

122 Qa 

945 766 

2,179 1,862 

1,006 868 

396 351 

310 297 

24 

159 

317 

140 

45 

13 

2,268 

71 

716 

971 

351 

112 

47 

2,472 1,517 

261 154 

1,369 778 

683 453 

66 47 

93 a5 

1,303 

128 

660 

389 

45 

- 

81 

214 

26 

ii8 

64 

2 

- 

4 

955 

107 

591 

230 

19 

20.3 12.5 10.7 

25.0 15.0 12.6 

21.0 12.2 10.4 

18.3 12.3 10.7 

16.4 11.9 11.4 

* l l 

8 . . . 

9.9 6.7 5.6 

12.8 7.9 6.2 

15.2 8.7 7.2 

10.2 7.0 5.9 

8.7 6.3 5.3 

7.0 5.2 4.4 

. . . 

8.4 

12.2 

12.6 

8.7 

7.3 

6.3 

. . . 

18.3 

17.5 

22.5 

la.0 

16.6 

14.6 

. . . 

. . . . . . 

. . . . . . 

5.8 4.7 

7.4 5.6 

7.3 6.0 

5.9 4.9 

5.2 4.3 

4.7 3.9 

. . . . . . 

12.5 10.8 

11.2 9.1 

13.1 11.0 

12.6 10.9 

12.5 10.8 

11.5 10.3 

. . . . . . 

1.8 7.9 

2.4 9.9 

1.8 8.8 

1.7 6.0 

* * 

* * 

. . . . . . 

1.1 3.2 

1.7 4.9 

1.5 6.5 

1.1 3.3 

1.0 2.5 

0.8 1.8 

*.. . . . 

1.0 2.7 

1.7 4.8 

1.3 5.3 

1.0 2.8 

0.9 2.1 

0.8 1.6 

. . . . . . 

1.8 5.7 

2.1 6.3 

2.1 9.5 

1.a 5.4 

1.7 4.2 

1.2 3.1 

. . . . . . 

llnchdas races other than tite and black. 

NOTE: Excludes data tom the States of Calfornia, Texas, ard Wasi-hgton. whkh did not report aduce.tional attainment of mother on birth cattiite. 
ki Table 8. Live births, infant deaths, and infant mortality rates, by age at death, race of child, and month of pregnancy prenatal care began: United States, 1985 birth cohort 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, O-6 days; late neonatal, 7-27 days: and postneonatal, 28 days-11 months. Not stated prenatal care proportionally distributed for calculation of rates. Rates are per 1,000 live births.] 

Race and month of Live Infant Total Early Late Post- infant Total Early Late Postpregnancy prenatal care began bilths deaths neonatal neonatal neonatal neonatal deaths neonatal neonatal neonatal neonatal 

Ail races’ ....... 

First month ...... 

Second month .... 

Third month ...... 

Fourth month ..... 

Fifth month ...... 

Sixth month ...... 

Seventh month .... 

Eighth month ..... 

Ninth month. ..... 

No care. ........ 

Not stated ....... 

White .......... 

First month ...... 

Second month .... 

Third month ...... 

Fourth month ..... 

Fifth month ...... 

Sixth month ...... 

Seventh month .... 

Eighth month ..... 

Ninth month. .... 

No care. ........ 

Not stated ....... 

Black .......... 

First month ...... 

Second month .... 

Third month ...... 

Fourth month ..... 

Fiih month ...... 

Sixth month ...... 

Seventh month .... 

Eighth month ..... 

Ninth month. ..... 

No care. ........ 

Not stated ....... 

. . 

. . 

. . 

. 

. . 

. . 

. . 

. 

. 

. . 

608,309 11,140 7,339 6,294 1,045 3,801 18.3 12.1 10.3 1.7 6.2 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

. . 

Number Rate 

3,760,833 39,145 25,573 21,317 4,256 13,572 10.4 6.8 5.7 1.1 3.6 

525,903 5,156 3,716 3,103 613 1,440 

1,449,461 12,477 8,514 7,097 1,417 3,963 

826,634 7,780 4,908 4,067 841 2,852 

347,044 3,603 2,070 1,671 399 1,533 

196,418 2,244 1,273 1,015 258 971 

120,002 1,355 617 474 143 738 

80,613 784 305 206 99 479 

47,328 431 160 112 48 271 

20,683 243 122 90 32 121 

61,481 2,579 1.906 1,712 194 673 

85,268 2,513 1,982 1,770 212 531 

10.3 7.5 6.3 1.2 2.8 

9.0 6.2 5.2 1.0 2.8 

9.8 6.3 5.2 1.0 3.5 

10.8 6.3 5.1 1.2 4.5 

11.9 6.9 5.5 1.3 5.0 

11.7 5.4 4.2 1.2 6.2 

10.0 4.0 2.7 1.3 6.0 

9.4 3.8 2.5 1.0 5.8 

12.2 6.2 4.6 1.6 5.9 

43.9 32.8 29.6 3.2 11.1 

. . . . 

2,991,521 26,526 17,381 14,323 3,058 9,145 8.9 5.8 4.8 1.0 3.1 

435,896 3,717 2,720 2,264 456 997 

1,233,840 9,408 6,402 5,290 1,112 3,004 

658,355 5,332 3,327 2,713 614 2,005 

250,752 2,165 1,249 984 265 916 

133,411 1.314 746 583 163 568 

80,251 820 373 290 63 447 

54,473 488 192 133 59 296 

31,838 260 100 71 29 180 

13,991 148 72 55 17 76 

38,823 1,256 910 802 108 346 

59,891 1,820 1,290 1,138 152 330 

8.9 6.6 5.5 1.1 2.3 

8.0 5.5 4.6 0.9 2.5 

8.4 5.3 4.4 1.0 3.1 

9.0 5.3 4.2 1.1 3.7 

10.2 5.9 4.7 1.3 4.3 

10.6 4.9 3.8 1.1 5.7 

9.2 3.7 2.6 1.1 5.5 

8.4 3.3 2.4 0.9 5.1 

11.0 5.4 4.2 l 5.5 

33.9 24.8 22.0 2.9 9.0 

. . . . . . . . . . . . . . . 

68,582 1,229 866 734 132 363 

161,472 2,653 1,839 1,567 252 814 

133,662 2,146 1,433 1,232 201 713 

79,832 1,285 750 628 122 535 

52,834 828 467 364 63 359 

33,045 470 218 166 52 252 

21,509 249 97 62 35 152 

12,429 148 52 36 16 96 

5,331 83 48 32 14 37 

19,886 1,255 954 870 84 301 

19,727 796 617 563 54 179 

18.7 13.3 11.4 

17.2 12.0 10.4 

16.7 11.3 9.8 

16.7 9.9 8.4 

16.2 9.3 7.7 

14.7 6.9 5.3 

Il.9 4.7 3.1 

12.2 4.4 3.1 

16.1 9.1 6.4 

65.9 50.6 46.3 

2.0 

1.6 

1.5 

1.6 

1.6 

I .6 

1.7 

4.3 

5.4 

5.1 

5.4 

6.8 

6.9 

7.7 

7.2 

7.8 

7.0 

15.3 

. . . . . . . . . . 

IIncludes races other than white and black. 
Table 9. Live births, infant deaths, and infant mortality rates, by detailed race of child: United States, 1993,1994, and 1985 birth cohorts 

[Live births and infant deaths are by State of residence at birth. Race is according to race reported on the matching birth certificate. Infant deaths are under 1 year of age. Neonatal deaths are under 28 days; early 

neonatal, O-6 days; late neonatal, 7-27 days; and postneonatal, 28 days-11 months. Rates are per 1,000 live births.] 

Detailed race and L/V8 infant Total Eartv Late Post- Infant Total Early Late postbirth cohort births deaths neonatal neonatal naonatal neonatal deaths neonatal neonatal neonatal naonatal 

1983 birth cohort Number Rate 

All races ..................... 3,639,113 39,663 25,630 21,689 4,141 13,853 10.9 7.1 6.0 

Whiie ...................... 2904,381 27,094 17,786 14,858 2,928 9,305 9.3 6.1 5.1 

Black. ..................... 566,085 11,087 7,202 6,151 1,051 3,885 18.9 12.3 10.5 

American Indian or Alaskan Native ... 41,591 598 293 224 69 305 14.4 7.0 5.4 

Chinese .................... 14,368 127 78 64 14 49 8.8 5.4 4.5 

Japanese ................... 8,667 59 34 30 4 25 6.8 3.9 3.5 

Hawaiian ................... 7,313 78 50 46 4 28 10.7 6.8 6.3 

Filipino. .................... 17,658 144 89 70 19 55 8.2 5.0 4.0 

Other Asian or Pacific Islander. ..... 57,399 473 281 231 50 192 8.2 4.9 4.0 

Other races. * * 

................. 1,661 23 17 15 2 6 13.9 

1984 birth cohort 

All races ..................... 3,689,268 38,292 24,995 20,977 4,018 13,297 10.4 6.8 5.7 

White ...................... 2,923,627 26,168 17,178 14,304 2,874 8,980 8.9 5.9 4.9 

Black. ..................... 592,780 10,630 6,927 5,946 981 3,703 17.9 11.7 10.0 

American Indian or Alaskan Native ... 41,444 520 252 192 60 268 12.5 6.1 4.8 

Chinese .................... 18,185 115 67 59 8 48 7.1 4.1 3.8 

Japanese ................... 9,345 61 33 29 4 28 6.5 3.5 3.1 

Hawaiian ................... 7,260 90 60 52 8 30 12.4 8.3 7.2 

Filipino. .................... 19,855 170 105 92 13 65 8.6 5.3 4.6 

Other Asian or Paciftc Islander. ..... 56,577 520 350 283 67 170 9.2 6.2 5.0 

Other races. ................. 2,215 28 23 20 3 5 12.6 10.4 9.0 

1985 birth cohort 

All races ..................... 3,760,833 39,145 25,573 21,317 4,256 13,572 10.4 6.8 5.7 

White. ..................... 2991,521 26,526 17,381 14,323 3,058 9,145 8.9 5.8 4.8 

Black, ..................... 608,309 11,140 7,339 6294 1,045 3,801 18.3 12.1 10.3 

American Indian or Alaskan Native ... 42,647 531 254 208 46 277 12.5 6.0 4.9 

Chinese .................... 17,881 105 64 52 12 41 5.9 3.6 2.9 

Japanese ................... 9,803 63 39 31 8 24 6.4 4.0 3.2 

Hawaiian ................... 7,194 68 41 35 6 27 9.5 5.7 4.9 

Filipino. .................... 21,482 173 114 66 28 59 8.1 5.3 4.0 

Other Asian or Pacific Islander. ..... 59,263 512 323 274 49 189 8.6 5.5 4.6 

Other races. * l 

................. 2,733 27 18 14 4 9 9.9 

1.1 

1.0 

1.8 

1.7 

* 

* 

* 

* 

0.9 

l 

3.8 

3.2 

6.6 

7.3 

3.4 

2.9 

3.8 

3.1 

3.3 

l 

1.1 3.8 

1.0 3.1 

1.7 6.2 

1.4 6.5 

* 3.0 

* 3.0 

* 4.1 

l 3.3 

1.2 3.0 

* * 

1.1 3.6 

1.0 3.1 

1.7 6.2 

1.1 6.5 

* 2.3 

* 2.4 

* 3.8 

1.3 2.7 

0.8 3.2 

l * 
Appendix 

Contents 

Technicalnotes .......................................................................................... 35 

Nature and sources of data ............................................................................. 35 

Race classification .................................................................................... 

35 

Births by marital status of mother ....................................................................... 35 

Not-stated values and computation of percent distributions and infant mortality rates. ............................. 35 

Random variation .................................................................................... 36 

84 
Appendix 

Technical notes 

Nature and sources of data 

Data in this report for the 1983, 1984, and 1985 birth 

cohorts of live births and infant deaths are from birth certificates and death certificates for infants tied in the 50 States and 

the District of Columbia. Some of the data were coded by the 

National Center for Health Statistics (NCHS) from copies of 

original certi8cates received from the State registration offices 

and the remainder by the States, who provided them to NCHS 

through the Vital Statistics Cooperative Program (VSCP). 

For 1983 and 1984, the VSCP included 46 States, which 

provided data based on 100 percent of their birth certificates. 

Data on births for 1983 and 1984 for Arizona, California, 

Delaware, the District of Columbia, and Georgia were based 

on a 50-percent sample of birth certificates, the evennumbered certiticates fifed in those States and coded by 

NCHS. To the national file of linked birth and irAnt death 

records was added information coded by NCHS for the 

odd-numbered birth certificates for those infants who died. 

Sampling procedures and sampling errors for 1983 and 1984 

births are provided in the annual report, vital Statistics of the 

United States, Volume I, Natal@. For 1985, all States and the 

District of Columbia submitted data based on 100 percent of 

the birth certificates to NCHS through the VSCX? 

For 1983 and 1984, nonmedical mortality data were 

provided by the 46 States in the VSCP on computer tape to 

NCHS. For Arizona, California, Delaware, Georgia, and the 

District of Columbia, which were not participants in the 

VSCP, NCHS coded all the nonmedical data. For 1985 and 

1986, all States and the District of Columbia participated in 

the VSCP and submitted preceded nomuedical data for all 

deaths on computer tape to NCHS. 

Statistics on births and deaths for the United States refer 

to events occurring within the United States to U.S. residents. 

Residence in this report is based on the usual place of 

residence of the mother at the time of the infant’s birth. 

Race classification 

The racial designation used in this report is that of the 

child, which is determined from the race of the parents as 

entered on the birth certificate. When the parents are of 

diiferent races and one parent is white, the child is assigned to 

the other parent’s race. When the parents are of different races 

and neither parent is white, the child is assigned to the father’s 

race with one exception: If the mother is Hawaiian or part 

Hawaiian, the child is considered Hawaiian. When the race of 

one parent is missing on the certiticate, the child is assigned 

the race of the other parent. When race is not reported for 

either parent, the child is assigned the race of the child on the 

immediately preceding record. 

Births by marital status of mother 

Beginning with 1980 data, marital status of mother is 

derived from two sources. For 41 States and the District of 

Columbia, marital status is reported directly on the birth 

certificate; for the remaining 9 States, which lack such an 

item, marital status is inferred from a comparison of the 

child’s and parents’ surnames. This method represents an 

attempt to use related information on the bii certificate to 

improve the quality of national data on this topic as well as to 

provide data for the individual nonreporting States. The method 

is based on a comparison of the child’s surname, the mother’s 

present and maiden surnames, and the father’s surname. An 

evaluation of the new method and its continuing validity for 

California (the largest nonreporting State) was recently published (14). 

Because of the substantial increase in all measures of 

nomnarital childbearing in 1985, an intensive evaluation of the 

national data was made. There has been contimring concern 

that the new method, incorporating data based on a comparison of surnames, might overstate the number of births to 

unmarried women, particularly among those women who have 

retained their maiden surname as their legal surname after 

marriage. The evaluation included comparisons of trends in all 

measures of births to unmarried mothers between 1980, when 

the new method was first put into use, and 1985. Trends in 

States with a marital status item on the birth certificate were 

compared with trends in those States providing inferential data 

based on a comparison of surnames. The comparisons were 

made for white and black births separately and by age of 

mother. The results were remarkably similar for both data sets. 

Nomnarital births increased at virtually the same rate in both 

sets of States. The 8ndings were similar for white and black 

women and for the various age-of-mother groups. 

Not-stated values and computation of 

percent distributions and infant mortality 

rates 

Vital records with not-stated values for variables in the 

source document are handled in two different ways during the 

35 
processing of data. Not-stated values for race of decedent, sex, 

mother’s age, and marital status are imputed based on other 

information on the record or on the previous record. Notstated values for the following variables are retained during 

processing: Mother’s educational attainment, month of pregnancy prenatal care began, live-birth order, birthweight, and 

date of last normal menstrual period (from which gestational 

age is derived). In this report, not-stated values for these 

variables are distributed in proportion to stated values for 

calculating percent distributions and variable-specik infant 

mortality rates. The proportional distribution of not-stated 

values for the denominator (live births) incorporates the 

distribution of not-stated values for the numerator, a subgroup 

of the denominator. 

Birth cohort infant mortality rates shown throughout this 

report are based on deaths under 1 year of age that occur in the 

year of birth or the following year to all infants born in a 

calendar year, the birth cohort. Birth cohort infant mortality 

rates differ from the more commonly used measure of infant 

mortality, which is based on the number of live births and 

infant deaths that occur in the same calendar year period. 

Period infant mortality rates are published by NCHS in W&E 

Statistics of the United States, Volume ZJ Mortality, section 2. 

Birth cohort infant mortality rates are calculated by 

dividing the number of infant deaths to the birth cohort by the 

number of live births in the cohort and are presented as rates 

per 1,000 live births in the cohort. In contrast, period infant 

mortality rates based on annual data are calculated by dividing 

the number of infant deaths in a calendar year by the number 

of live births registered for the same period and are also 

presented as rates per 1,000 live births. In this report, only 

birth cohort infant mortality rates are presented. 

Random variation 

Although the mortality data in this report are not subject 

to sampling error, they may be affected by random variation in 

the number of deaths involved. When the number of events is 

small (perhaps less than 100) and the probability of such an 

event is small, considerable caution must be observed in 

interpreting the data. Such infrequent events may be assumed 

to follow a Poisson probability distribution. For this distribution, a simple approximation may be used to estimate the 

cotidence interval, as follows: 

If N is the number of registered deaths in the population 

and R is the corresponding rate, the chances are 19 in 20 

(95-percent confidence interval) that 

N-247 and N-i=2 fl 

covers the “true” number of events; and 

(R-2)$ and (R+2) $ 

covers the “true” rate. 

If the rate R corresponding to N events is compared with 

the rate S corresponding to M events, the difference ‘between 

the two rates may be regarded as statistically significant if it 

exceeds 

2 

Additional information on random variation may be found in 

the Technical appendix of Vital Statistics of the United States, 

1988, Volume D, Mortality, Part A. 

36 ‘U.S. Government Pdntlng Oflice: lBQ4 - 301-019100009 
Vital and Health Statistics 

series descriptions 

SERIES 1. 

SERIES 2. 

SERIES 3. 

SERIES 4. 

SERIES 5. 

SERIES 6. 

SERIES 10. 

SERIES Il. 

SERIES 12. 

SERIES 13. 

Programs and Collection Procedures-These reports 

describe the data collection programs of tha National Center 

for Health Statistics. They Include descriptions of the 

methods used to collect and process the data, definitions, 

and other material necessary for understanding the data. 

Data Evaluation and Methods Research-These reports 

are studies of new statistical methods and include analytical 

techniques, objective evaluations of reliablllty of collected 

data, and contributions to statistical theory. These studies 

also include experimental tests of nevl survey methods and 

comparisons of U.S. methodology x!ith those of other 

countries. 

Analytical and Epidemiological Studies-These reports 

present analytical or interpretive studies based on vital and 

health statistics. These reports carry the analyses further than 

the expository types of reports in the other series. 

Documents and Committee Reports -These are final 

reports of major committees concerned with vital and health 

statistics and documents such as recommended model vital 

registration laws and revised birth and death certificates. 

International Vital and Health Statistics Reports-These 

reports are analytical or descriptive reports that compare U.S. 

vital and health statistics with those of other countries or 

present other international data of raievance to the health 

statistics system of the United States. 

Cognitlon and SurJey Measurement-These reports are 

from the National Laboratory for Collaboratrve Research in 

Cognition and Survey Measurement. They use methods of 

cognitive scmnce to design, evaluate, and test survey 

instruments. 

Data From the National Health IntervIew Survey-These 

reports contain statistics on Illness, unintentional injuries; 

disabGy; use of hospital, medrcal, and other health serxcss; 

and a v:ide range of special current health topics covenng 

many aspects of health behawors. health status, and health 

care utilization. They are based on data collected in a 

continuing national household interJie*:: survey. 

Data From the National Health Exmlnstion Survey, the 

National Health and Nutrition Exminatlon Surve;~, and 

the Hispanic Wealth and Nutrftlon Exomlnotion Survey - 

Data from direct exsminatlon, testing. and measurement on 

representative samples of the cw1i13fl nOnlnStltutiOnaliZPd 

population provide the basks for (1) medically defined tots1 

prevalence of specific diseases or ccnditlons II-T the United 

States and the distributions of the population with respect to 

physical, physiological, and psychologxal charactenshcs. 

and (2) analyses of trends and rolatlonshlps among various 

measurements and betxeen survey penods. 

Data From the lnstitutionailzed Population SurveysDiscontinued in 1975. Reports from these surveys are 

included in Series 13. 

Data From the National Health Care Survey-These 

reports contain statistics on health resources and the public’s 

use of health care resources includmg ambulatory, hospital. 

and long-term care services based on data collected directly 

from health care providers and prouder records. 

SERIES 14. 

SERIES 15. 

SERIES 16. 

SERIES 20. 

SERIES 21. 

SERIES 22. 

SERIES 23. 

SERIES 24. 

Data on Health Resources: Manpower and FaciiitiesDiscontinued in 1990. Reports on the numbers, geographic 

distribution, and characteristics of health resources are now 

included in Serres 13. 

Data From Special Surveys-These reports contain 

statistics on health and health-related topics collected in 

special surveys that are not part of the continuing data 

systems of the National Center for Health Statistics. 

Compilations of Advance Data From Vital and Health 

Statistics-Advance Data Reports provide early release of 

information from the National Center for Health Statistics’ 

health and demographic surveys. They are compiled in the 

order in *which they are published. Some of these releases 

may be followed by detailed reports in Series 10-13. 

Data on Mortality-These reports contain statistics on 

mortaliti{ that are not included in regular, annual, or monthly 

reports. Special analyses by cause of death, age, other 

demographic variables, and geographic and trend analyses 

are included. 

Data on Natality, Marriage, and Divorce-These reports 

contain statistics on natality, marriage, and divorce that are 

not included in regular, annual, or monthly reports. Special 

analyses by health and demographic variables and 

geographic and trend analyses are included. 

Data From the National Mortality and Natality SurveysDiscontinued in 1975. Reports from these sample surveys, 

based on vital records, are no:v published in Series 20 or 2:. 

Data From the NatIonal Survey of Family Growth -These 

reports contain statistics on factors that affect birth rates, 

including contraception, infertility, cohabitation, marriage, 

divorce, and remarriage; adoption; use of medical care for 

family planning and infertrlity; and related maternal and infant 

health topics. These statistics are based on national survays 

of childbearing age. 

Compltations of Data on Natality, Mortality, Marriage, 

Divorce, ond Induced Terminations of PregnancyThese include advancu reports of births, deaths, marriages, 

and divorces based on final data from the National Vital 

Statistics System that v:era published as supplements to the 

Xonthiy K&t Sk~tCtfcs Re,cott (MVSR). These repoti provide 

highlights and summaries of detailed data subsequently 

published in Vital State&s of the United States. Other 

supplements to the MVSR published here provide selected 

findings based on final data from the National Vital Statistics 

System and may be folloxd by detailed repons in Series 20 

or21. 

For ans?;ers to questions about this report or for a list of reports published 

in these series, contact: 

Data Dissemination Branch 

National Center for Health Statistics 

Centers for Disease Control and Prevention 

Public Health Service 

6525 Belcrest Road, Room 1064 

Hyattsville, t.lD 20762 

(301) 43543500 
Public Health Service 

Centers for Disease Control and Prevention 

National Center for Health Statistics 

6525 Belcrest Road 

Hyattsville, Maryland 20782 

0FFlClk.L BUSINESS 

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