Series 20

No. 26

Perinatal Mortality in the

United States: 1985–91

August 1995

Vital and

Health Statistics

From the CENTERS FOR DISEASE CONTROL AND PREVENTION / 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
Copyright information

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

reproduced or copied without permission; citation as to source, however, is

appreciated.

Suggested citation

Hoyert DL. Perinatal mortality in the United Sates, 1985–91. National Center for

Health Statistics. Vital Health Stat 20(26). 1995.

Library of Congress Cataloging-in-Publication Data

Perinatal mortality in the United States.

p. cm. — (Vital and health statistics. Series 20, Data from the national vital

statistics system ; no. 26) (DHHS publication ; no. (PHS) 95-1854)

‘‘August 1995’’.

ISBN 0-8406-0508-0

1. Perinatal death—United States—Statistics. 2. Perinatal death—United

States—States—Statistics. 3. United States—Statistics, Medical. I. National

Center for Health Statistics (U.S.) II. Series. III. Series: DHHS publication ; no.

(PHS) 95-1854.

HB1335.A18 no. 26

[RG632.U6]

304.6’4’097302 s—dc20 95-30868

[304.6’4] CIP
Perinatal Mortality

in the United States:

1985–91

Series 20:

Data From the National Vital

Statistics System

No. 26

This report presents recent trend data on perinatal mortality. Deaths and

mortality rates are shown by race and State. In addition, the rank of the

United States’ perinatal mortality rate relative to other countries is presented.

Hyattsville, Maryland

August 1995

DHHS Publication No. (PHS) 95-1854

Vital and

Health Statistics

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

Centers for Disease Control and Prevention

National Center for Health Statistics
National Center for Health Statistics

Jack R. Anderson, Acting Director

Jennifer H. Madans, Ph.D., Acting 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 Vital and Health

Statistics Systems

(Vacant), 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

Division of Vital Statistics

Mary Anne Freedman, Director

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

Harry M. Rosenberg, Ph.D., Chief, Mortality Statistics

Branch

Robert J. Armstrong, Acting Chief, Statistical Resources

Branch

Joseph D. Farrell, Chief, Systems and Programming Branch
Contents

Highlights .............................................................................................. 1

Introduction............................................................................................. 2

Development of perinatal mortality measures ............................................................... 2

Components of fetal and infant mortality................................................................... 3

Trends and differentials in perinatal mortality ................................................................. 5

Race and ethnic differentials ............................................................................. 5

Geographic differentials................................................................................. 6

International comparisons, 1950–90 ....................................................................... 6

References.............................................................................................. 9

List of detailed tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Appendix

Technical notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Text table

A. Number and percent distribution of components of fetal and infant deaths combined: United States, 1950, 1960, 1970,

1980, and 1985–91 ................................................................................... 4

Figures

1. Percent distribution of fetal and infant deaths combined: United States, 1991.................................... 3

2. Perinatal mortality by race: United States, 1950–91 ........................................................ 5

3. Perinatal mortality rates for all races by State, 1989–91 ..................................................... 6

4. Perinatal mortality rates for the white population by State, 1989–91 ........................................... 7

5. Perinatal mortality rates for the black population by State, 1989–91 ........................................... 7

6. International perinatal rates: United States and world’s lowest rate, 1950–90 .................................... 8

Symbols

- - - Data not available

. . . Category not applicable

– Quantity zero

* Figure does not meet standard of

reliability or precision (estimate is based

on fewer than 20 deaths in numerator or

denominator)

iii
Perinatal Mortality in the

United States: 1985–91

by Donna L. Hoyert, Ph.D., Division of Vital Statistics

Highlights

In 1991 a total of 35,926 perinatal deaths occurred in the

United States; this includes fetal deaths occurring at 28 weeks

of gestation or later and infant deaths occurring under 7 days

of age. The perinatal mortality rate was at a record low of 8.7

perinatal deaths per 1,000 live births and fetal deaths, 19 percent lower than the rate in 1985.

Perinatal mortality rates differ by race. In 1991 the rates

for the white and black populations were 7.4 and 15.7

perinatal deaths per 1,000 live births and fetal deaths, respectively. The rate for the Hispanic population was 7.9 compared

with a rate of 7.1 for the non-Hispanic white population of an

area comprised of 36 States and the District of Columbia. This

area includes those States that reported Hispanic origin and

whose reporting completeness was considered adequate for

analysis.

Variation in perinatal mortality rates is evident within the

United States. States with the lowest rates typically are located

west of the Mississippi River and States with the highest rates,

east of the Mississippi. Geographic patterns differ by race, but

a few States have either high or low rates for the black and

white populations. Likewise, perinatal mortality rates differ

between the United States and other industrialized countries.

In terms of international ranking of perinatal rates, the substantial decline in the rate in the United States has been less

than that of other industrialized countries. Consequently, the

U.S. rank has deteriorated over the past 40 years relative to

other industrialized countries.

The trends observed for perinatal mortality are similar to

the trends for infant and fetal mortality. Rates for all three

decreased between 1985 and 1991 but the average annual

decrease is greatest for perinatal mortality.

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

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

Branch. This report closely follows the format of two previous reports on

perinatal mortality prepared by Eve Powell-Griner, Ph.D., formerly of the

National Center for Health Statistics staff. Marian F. MacDorman, Ph.D.,

Mortality Statistics Branch, and Robert B. Hartford, Ph.D., Office of International Statistics, peer-reviewed this report. Betty L. Smith of the Statistical

Resources Branch provided content review. Charles E. Royer of the Systems

and Programming Branch provided programming support. Staff of the Registration Methods Branch and the Technical Services Branch provided consultation to State vital statistics offices regarding collection of the vital statistics

data on which this report is based. This report was edited by Patricia

Keaton-Williams and typeset by Annette F. Facemire of the Publications

Branch, Division of Data Services.

1
Introduction

This report describes recent levels of perinatal mortality

in the United States for 1985–91. Two previous reports

described trends in perinatal mortality for the periods 1950–81

(1) and 1981–85 (2). Perinatal deaths include spontaneous

fetal deaths of a specified gestational age and neonatal deaths.

National Center for Health Statistics (NCHS) has developed

three definitions of perinatal mortality derived from data on

three types of vital events—fetal deaths, infant deaths, and live

births. These perinatal mortality measures supplement other

statistics on fetal and infant mortality published by NCHS in

Vital Statistics of the United States, Volume II, Mortality,

Part A.

Development of perinatal mortality

measures

Perinatal mortality is comprised of fetal and infant deaths.

A fetal death refers to the death of a product of human

conception before complete extraction or expulsion from its

mother, irrespective of the duration of pregnancy (3). In this

report, fetal deaths refer only to deaths of fetuses of at least 20

weeks of gestation. (For further details, see Technical notes.)

Fetal deaths can be further characterized as ‘‘early’’ (20–27

weeks of gestation) and ‘‘late’’ (28 weeks of gestation or

more). An infant death refers to the death of a liveborn infant

under 1 year of age. Typically, infant deaths are described in

terms of neonatal (under 28 days of age) and postneonatal

(aged 28 days–11 months) deaths. Neonatal deaths can be

further divided into ‘‘early’’ (under 7 days of age) and ‘‘late’’

(aged 7–27 days) components. Perinatal deaths refer to a

combination of fetal deaths of at least 20 weeks of gestation

and neonatal deaths; definitions of perinatal death used by

NCHS vary depending on whether deaths in the ‘‘early’’ or

‘‘late’’ fetal or neonatal periods are included (1).

The concept of a perinatal period emerged in the late

1940’s as physicians and other researchers became increasingly aware of the relatively large number of deaths occurring

in the period immediately before and after delivery. This

concept reflected the belief that circumstances responsible for

the majority of neonatal deaths arose from conditions established before delivery or from the stresses introduced by the

birth process. Because many of these same circumstances

were responsible for fetal deaths at 20 weeks of gestation or

more, a concept that combined fetal deaths of at least 20

weeks of gestation with infant deaths under 28 days of age

seemed particularly useful in studying reproductive loss (4).

Another factor contributing to the interest in developing a new

mortality measure was the awareness that some infant deaths

occurring shortly after birth were reported as fetal deaths and

that fetal deaths were sometimes reported as infant deaths (1).

The term ‘‘perinatal mortality’’ was first proposed by

Sigismund Peller in 1948 (5) to denote deaths of fetuses

during pregnancy and labor and deaths of infants in the early

days of life. In 1954 the World Health Organization (WHO)

supported the concept of perinatal mortality but did not

specify the range of the perinatal period (6). The 1956 Public

Health Conference on Records and Statistics (PHCRS) in the

United States recommended that for general use in analysis of

vital record data within this country the perinatal mortality rate

include fetal deaths at 20 weeks of gestation or more and

infant deaths under 7 days of age. However, PHCRS acknowledged the usefulness of perinatal mortality rates based on fetal

deaths at 20 weeks of gestation or more and infant deaths

under 28 days of age, particularly for evaluation of maternal

and child health programs (7). In 1965 the WHO recommended that the definition of the perinatal period include fetal

deaths from the 28th completed week of pregnancy and

neonatal deaths of under 7 days of age. At that time, the WHO

also encouraged countries not already doing so to extend

requirements for reporting of perinatal data down to the 20th

completed week of gestation and up to the 28th day of life (8).

The recommendations of the WHO and PHCRS are the

basis for the three perinatal mortality measures generally used

in the United States. Perinatal Definition I, the most restrictive

definition, refers only to fetal deaths at 28 weeks of gestation

or more and infant deaths under 7 days of age. The most

inclusive measure, Perinatal Definition II, refers to fetal deaths

at 20 weeks of gestation or more and infant deaths under 28

days of age. Perinatal Definition III includes fetal deaths at 20

weeks of gestation or more and infant deaths under 7 days of age.

Effective with data for 1979, NCHS began publishing

statistics for all three perinatal measures; however, this report,

like the two previous reports (1,2), focuses on Perinatal

Definition I for the following reasons:

+ Definition I limits the infant death group to those under 7

days of age; during this early infant period, prenatal

conditions and circumstances surrounding the delivery

have more effect on mortality than do postnatal factors (4).

+ Definition I limits fetal deaths to those at 28 weeks of

gestation or more; such deaths appear to be better reported

than those occurring before 28 weeks of gestation (9).

2
+ More than two-thirds of all perinatal deaths by the broadest definition (II) occurred within the period encompassed

by Definition I in 1991.

+ Definition I is generally used for international comparisons.

Although the text of this report emphasizes Perinatal

Definition I, the detailed tables show values for all three

perinatal definitions. Additional information on WHO recommendations and presentation of perinatal mortality is provided

in the Technical notes.

Measures of perinatal mortality estimate the risk of death

in the perinatal period and can be expressed as either a rate or

a ratio. The perinatal rate is defined as the number of perinatal

deaths per 1,000 live births and fetal deaths. The perinatal

ratio is the number of perinatal deaths per 1,000 live births.

The perinatal mortality rate is the preferred measure because

for any data year, the denominator more closely approximates

the population at risk. However, actual numerical differences

between perinatal mortality rates and ratios in the United

States are small, and the relative difference between the two

measures decreases as perinatal mortality decreases (2).

In recent years, other perinatal mortality measures have

been introduced. One of these, the feto-infant mortality rate

developed by the International Collaborative Effort on Perinatal and Infant Mortality, broadens perinatal mortality to include

the entire infant period (10). Like other perinatal mortality

measures, the feto-infant mortality rate avoids problems in the

distinction between a fetal death and live birth, which complicates, in particular, international comparisons. In comparison

to the traditional perinatal mortality rate, the feto-infant mortality rate provides more encompassing information on pregnancy performance through the first year of life. The perinatal

mortality measures presented in this report and the feto-infant

mortality rate ignore fetal losses early in pregnancy; although

these losses are an important component of pregnancy performance, they are poorly reported even in the industrialized

countries.

Components of fetal and infant mortality

The distribution of fetal deaths and infant deaths by age at

death for 1991 is shown in figure 1. The largest proportion of

these events is accounted for by early neonatal deaths (28.3 percent), followed by late fetal deaths (25.4 percent). Postneonatal deaths accounted for 20.6 percent of fetal deaths and infant

deaths combined. Fetal deaths at 20–27 weeks of gestation

(19.6 percent) and late neonatal deaths (6.1 percent) contributed least to reported fetal and infant mortality. Perinatal

deaths, according to Perinatal Definition I, included over

one-half (53.7 percent) of the infant deaths and fetal deaths at

20 weeks of gestation or more.

Trends in numbers of fetal and infant deaths and their

relative distribution are shown in table A. The sum of the

number of fetal deaths at 20 weeks of gestation or more and

infant deaths continued a long-standing pattern of decline,

decreasing from 69,691 in 1985 to 66,926 in 1991. The

percentage of fetal and infant deaths encompassed by Perinatal

Definition I deaths also continued to decrease, dropping from

58.2 percent in 1985 to 53.7 percent in 1991. The relative

proportion of the components changed, but ranking of the

components remained unchanged: Deaths of fetuses at 28

weeks of gestation or more and of early neonatal deaths were

greater than the numbers of deaths of any other component

group; late neonatal deaths contributed the fewest deaths of

any of the components. Between 1985 and 1991, the early

fetal death component increased from 15.7 to 19.6 percent of

all fetal and infant deaths, continuing an earlier trend that may

reflect improvements in reporting early fetal deaths.

20 27 weeks of

gestation (19.6)

28 days 11 months

of age (20.6)

7 27 days

of age (6.1)

28 weeks of

gestation or

more (25.4)

Under 7 days

of age (28.3)

Fetal deaths

Neonatal

Postneonatal

NOTES: Perinatal Definition I comprises 53.7 percent of infant and fetal deaths

combined, Perinatal Definition II comprises 79.4 percent of infant and fetal

deaths combined, and Perinatal Definition III comprises 73.3 percent of infant

and fetal deaths combined.

Infant deaths

Figure 1. Percent distribution of fetal and infant deaths

combined: United States, 1991

3
Table A. Number and percent distribution of components of fetal and infant deaths combined: United States, 1950, 1960, 1970, 1980, and

1985–91

Infant deaths

Fetal deaths Neonatal deaths

Year

Fetal and

infant

deaths

Early

(20–27

weeks of

gestation)1

Late

(28 weeks

of gestation

or more)1

Early

(Under 7 days

of age)

Late

(7–27 days

of age)

Postneonatal

deaths (28

days–11 months

of age)

Perinatal

Definition I 2

Number

1991 ......................... 66,926 13,150 17,010 18,916 4,062 13,788 35,926

1990 ......................... 69,737 13,427 17,959 20,020 4,289 14,042 37,979

1989 ......................... 70,124 12,405 18,064 20,796 4,372 14,487 38,860

1988 ......................... 68,352 11,855 17,587 20,471 4,219 14,220 38,058

1987 ......................... 67,757 11,683 17,666 20,471 4,156 13,781 38,137

1986 ......................... 67,863 11,115 17,857 21,053 4,159 13,679 38,910

1985 ......................... 69,691 10,958 18,703 21,865 4,314 13,851 40,568

1980 ......................... 78,879 10,754 22,599 25,492 5,126 14,908 48,091

1970 ......................... 127,528 17,170 35,791 50,821 5,458 18,288 86,612

1960 ......................... 179,353 16,496 51,984 71,125 8,608 31,140 123,109

1950 ......................... 172,087 14,522 53,740 63,417 9,438 30,970 117,157

Percent distribution

1991 ......................... 100.0 19.6 25.4 28.3 6.1 20.6 53.7

1990 ......................... 100.0 19.3 25.8 28.7 6.2 20.1 54.5

1989 ......................... 100.0 17.7 25.8 29.7 6.2 20.7 55.4

1988 ......................... 100.0 17.3 25.7 29.9 6.2 20.8 55.7

1987 ......................... 100.0 17.2 26.1 30.2 6.1 20.3 56.3

1986 ......................... 100.0 16.4 26.3 31.0 6.1 20.2 57.3

1985 ......................... 100.0 15.7 26.8 31.4 6.2 19.9 58.2

1980 ......................... 100.0 13.6 28.7 32.3 6.5 18.9 61.0

1970 ......................... 100.0 13.5 28.1 39.9 4.3 14.3 67.9

1960 ......................... 100.0 9.2 29.0 39.7 4.8 17.4 68.6

1950 ......................... 100.0 8.4 31.2 36.9 5.5 18.0 68.1

1Figures for gestational age not stated are distributed; see Technical notes.

2Perinatal Definition I refers to infant deaths under 7 days of age (early neonatal) and fetal deaths with stated or presumed gestation of 28 weeks or more (late fetal). Figures for gestational age

not stated are distributed for fetal deaths. The numbers for Definition I differ from those published in Vital Statistics of the United States, Volume II; see Technical notes.

4
Trends and differentials in

perinatal mortality

In 1991 a total of 35,926 perinatal deaths occurred in the

United States, a decrease of 4,623 (11 percent) from the

number in 1985 (table A). The perinatal mortality rate of 8.7

perinatal deaths per 1,000 live births and fetal deaths (Perinatal Definition I) is the lowest perinatal rate yet recorded in the

United States; it represents a decrease of 19 percent since

1985, continuing the generally downward trend since 1950

(figure 2 and table 1).

The average annual decline in the perinatal mortality rate

between 1985 and 1991 (3.4 percent) was somewhat less than

the decline in the rate between 1980 and 1985 (4.1 percent)

because of a slowing in the rate of decline for neonatal and

late fetal mortality. The average annual decline in the early

neonatal mortality rate slowed from 4.0 percent during 1980 to

1985 to 3.8 percent between 1985 and 1991. Likewise, the

decline in the late fetal mortality rate decelerated from 4.6 percent to 2.9 percent annually during these two periods,

respectively.

However, perinatal mortality declined more rapidly than

either infant mortality (all deaths of infants under 1 year of

age) or fetal mortality (gestations of 20 weeks or more) during

1985 through 1991. The 1991 infant mortality rate of 8.9

infant deaths per 1,000 live births is the lowest rate ever

recorded in the United States. Likewise, the fetal mortality rate

of 7.3 fetal deaths per 1,000 live births and fetal deaths is the

lowest rate yet recorded in the United States. The average

annual decrease in infant and fetal mortality rates (2.9 and

1.1 percent, respectively) was less than that for the perinatal

mortality rate (Perinatal Definition I) between 1985 and 1991

(3.4 percent). This reflects that perinatal mortality is comprised of two subcomponents of fetal and infant mortality, a

late fetal and an early neonatal period component, for which

rates decreased more than for the total fetal and infant rates,

respectively.

Race and ethnic differentials

The perinatal mortality rate for the black population in

1991 (15.7) was 2.1 times that of the white population (7.4)

(table 1), considerably higher than the ratio of the rates in

1985 (1.9). The widening gap in perinatal mortality between

the two major race groups results from a much greater slowing

in the rate of decline in perinatal mortality for the black

population compared with the white population. For the white

population, the average annual decline in the perinatal mortality rate between 1985 and 1991 was 4.1 percent compared to

4.2 between 1980 and 1985. For the black population, the

declines were 2.2 percent and 3.4 percent, respectively. (For

details on tabulation of race in perinatal mortality, see Technical notes.)

Changes in both major components of perinatal mortality

contributed to the increase in the race differential in perinatal

mortality during 1985 through 1991. The decline in the late

fetal mortality rate (fetal deaths at 28 weeks of gestation or

more) was much greater for white fetuses (17.8 percent) than

for black fetuses (12.5 percent). Similarly, the decline in the

early neonatal mortality rate (infant deaths under 7 days of

age) was substantially greater for the white population (26.0 percent) than for the black population (13.0 percent).

In 1991 the perinatal mortality rate for the Hispanic

population (7.9) was 11 percent higher than that of the nonHispanic white population (7.1) for an area comprised of 36

States and the District of Columbia (table 2). States included

were those with an Hispanic-origin item and at least 90 percent completion of the item on a place-of-occurrence basis. In

the 1990 Census 83 percent of the Hispanic population living

in the United States lived in this area.

1

3

5

7

10

30

50

70

100

Rate per 1,000 births and fetal deaths

1950 1955 1960 1965 1970 1975 1980 1985 1990

Year

NOTES: Rates for all other, white, and black are by race of child for 1950 69

and by race of mother for 1970 91. See Technical notes for details on change

in tabulation by race.

All

races

Black All White

other

Figure 2. Perinatal mortality by race: United States, 1950–91

5
Race and ethnic differentials in perinatal mortality like

those for infant mortality may reflect differences in socioeconomic status, access to medical care, and the prevalence of

specific risks (11). Likewise, race and ethnic differentials in

perinatal mortality are associated with differentials in the

birthweight distribution of these groups. Vital statistics data

available for 1988 (not shown in this report) indicate that more

than three-quarters of all perinatal deaths were of low birthweight although fewer than one-tenth of the deliveries were of

low birthweight (12).

Geographic differentials

Perinatal mortality rates (Perinatal Definition I) are shown by

State and race in this report for the combined period of 1989–91

to increase the reliability and stability of the rates (table 3).

Perinatal mortality rates varied greatly by State, with a range of

6.1 to 21.2 perinatal deaths per 1,000 live births and fetal deaths.

Perinatal mortality generally is less than the national rate

for States west of the Mississippi River and in New England

and greater than the national rate for States with borders on the

Gulf of Mexico and the Atlantic Ocean (e.g., Georgia, Louisiana, New York, North Carolina) (figure 3). Rates are also

greater than the national rate in Illinois and Indiana. Data

limitations that affect geographic comparability are discussed

in the Technical notes.

Geographic patterns of perinatal mortality differ by race;

however, there are some similarities. For the white population

(figure 4), more States with lower rates than the national rate

are located west of the Mississippi River and all States with

higher rates are east of the Mississippi. Two groups of

adjoining States with high rates are evident: (a) Illinois,

Indiana, Ohio, West Virginia, Pennsylvania, and New York,

and (b) Alabama, Georgia, South Carolina, and North Carolina.

For the black population (figure 5), States in the West

South Central region (i.e., Arkansas, Louisiana, Oklahoma,

and Texas) have lower perinatal rates than the national rate.

The States with higher rates than the U.S. perinatal mortality

rate are located within or near the previously noted high States

for the white population. High States common to both race

groups are Georgia, Illinois, New York, and Pennsylvania, and

low States in common are Alaska and Massachusetts.

International comparisons, 1950–90

Although perinatal mortality has declined in the United

States by more than 70 percent between 1950 and 1990, the

United States’ ranking (table 4) relative to countries with at

least 1 million population and complete demographic counts

has deteriorated over the same period from 3rd lowest to 19th

lowest perinatal mortality rate (13). Data limitations that affect

international comparability of perinatal statistics are discussed

in the Technical notes.

NOTE: Includes rates for Perinatal Definition I only.

Rate significantly higher than U.S.:

Rate significantly lower than U.S.:

Other than 10 highest rates

10 lowest rates

10 highest rates

Other than 10 lowest rates

Rate not significantly different than U.S.

D.C.

Figure 3. Perinatal mortality rates for all races by State, 1989–91

6
NOTE: Includes rates for Perinatal Definition I only.

Rate significantly higher than U.S.:

Rate significantly lower than U.S.:

Other than 10 highest rates

10 lowest rates

10 highest rates

Other than 10 lowest rates

Rate not significantly different than U.S.

D.C.

Figure 4. Perinatal mortality rates for the white population by State, 1989–91

NOTE: Includes rates for Perinatal Definition I only.

Rate significantly higher than U.S.:

Rate significantly lower than U.S.:

Other than 10 highest rates

10 lowest rates

10 highest rates

Other than 10 lowest rates

Rate not significantly different than U.S.

D.C.

Figure 5. Perinatal mortality rates for the black population by State, 1989–91

7
The list of countries for which perinatal mortality rates

have been ranked between 1950 and 1990 has changed.

During this period, countries such as Chile, Costa Rica, Cuba,

the German Democratic Republic, and Greece have been

added to those considered in ranking perinatal rates. However,

the only country with a lower rate than the United States in

1990 that was not in the list in 1950 is Northern Ireland.

Consequently, the change in the U.S. rank does not result from

changes in the list of countries that are ranked.

Instead, over this 40-year period, the ranking of the

United States’ perinatal mortality rate deteriorated because the

decline in the rate in the United States has not kept pace with

the decline in other countries (figure 6). The perinatal rate for

the United States in the 1950’s was roughly 20 percent greater

than that for the country with the best rate; by the 1980’s, the

U.S. rate was close to 60 percent greater than that for the

country with the lowest rate. As the differential between the

United States and the country with the lowest perinatal rate

widened, rates for 14 countries that had higher perinatal rates

than the United States in 1950 improved to the point where

their rates were better than that of the United States in 1990.

These countries include Australia, Austria, Canada, Denmark,

England and Wales, Finland, Federal Republic of Germany,

Hong Kong, Japan, New Zealand, Scotland, Singapore, Sweden, and Switzerland.

1

3

5

7

10

30

50

70

100

Rate per 1,000 births and fetal deaths

1950 1955 1960 1965 1970 1975 1980 1985 1990

Year

United States

World’s lowest rate

NOTE: Numerous countries have had the lowest rate over the period 1950 90.

Figure 6. International perinatal rates: United States and world’s

lowest rates, 1950–90

8
References

1. National Center for Health Statistics. Perinatal mortality in the

United States: 1950–81. Monthly vital statistics report; vol 34,

no 12, supp. Hyattsville, MD: Public Health Service. 1986.

2. National Center for Health Statistics. Perinatal mortality in the

United States: 1981–85. Monthly vital statistics report; vol 37,

no 10, supp. Hyattsville, MD: Public Health Service. 1989.

3. National Center for Health Statistics. Model State Vital Statistics Act and Model State Vital Statistics Regulations. Washington: Public Health Service. 1978.

4. Shapiro S, Schlesinger ER, Nesbitt Jr., REL. Infant, perinatal,

maternal, and childhood mortality in the United States. Cambridge: Harvard University Press. 1968.

5. Peller S. Mortality, past and future. Population Studies 1(4):405–

56. 1948.

6. United Nations. Handbook of vital statistics methods. New

York, 1955.

7. Public Health Conference on Records and Statistics. Background statement on a perinatal mortality index. Document No.

398, attachment B, Washington: National Office of Vital Statistics. 1956.

8. World Health Organization. Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death,

based on the recommendations of the Eighth Revision Conference. Geneva: World Health Organization. 1967.

9. Shapiro S, Schlesinger ER, Nesbitt REL. Infant and perinatal

mortality in the United States. National Center for Health

Statistics. Vital and Health Stat 3(4). 1965.

10. Hartford RB. Definitions, standards, data quality, and comparability. In: National Center for Health Statistics. Proceedings of

the international collaborative effort on perinatal and infant

mortality, volume III. Hyattsville, Maryland: Public Health

Service. II-12–6. 1992.

11. Gould JB, Davey B, LeRoy S. Socioeconomic differentials and

neonatal mortality: Racial comparison of California singletons.

Pediatrics 83(2):181–6. 1989.

12. National Center for Health Statistics. Public use data tape

documentation: Linked birth/infant death data set: 1988 birth

cohort. Hyattsville, MD: Public Health Service. 1994.

13. National Center for Health Statistics. International infant mortality data set.

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

United States, 1991, vol I, natality. Washington: Public Health

Service. (In preparation).

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

United States, 1991, vol II, mortality, part A. Washington:

Public Health Service. (In preparation).

16. Hoyert DL. Effect on mortality rates of the 1989 change in

tabulating race. National Center for Health Statistics. Vital

Health Stat 20(25). 1994.

17. United Nations: Demographic yearbook 1991. New York, New

York: United Nations. 1991.

18. Klinger A. Infant mortality in Eastern Europe, 1950–1980.

Budapest: Statistical Publishing House. 1982.

19. Kleinman JC. Underreporting of infant deaths: Then and now.

AJPH 76(4):365–6. 1986.

20. Haenszel W, Loveland DB, Sirken MG. Lung cancer mortality

as related to residence and smoking histories. I. White males.

JNCI 28:947–1001. 1962.

9
List of detailed tables

1. Perinatal mortality rates for perinatal definitions I, II, and

III by race: United States, 1950–91 . . . . . . . . . . . . . . . . 11

2. Perinatal mortality rates by specified Hispanic origin and

race for non-Hispanic origin: Total of 31 States, 1989, and

36 States and the District of Columbia, 1990 and 1991 . . 13

3. Perinatal mortality rates for perinatal definitions I, II, and

III by race: United States, each State, and the District of

Columbia, 1989–91 combined . . . . . . . . . . . . . . . . . . . . 14

4. Trends in the international ranking of perinatal mortality:

1950–90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

10
Table 1. Perinatal mortality rates for perinatal definitions I, II, and III by race: United States, 1950–91

[Perinatal Definition I includes infant deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 28 weeks or more; Perinatal Definition

II includes infant deaths under 28 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more; Perinatal Definition III includes infant

deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more. Rates per 1,000 live births and fetal deaths in specified

group]

Year

Perinatal Definition I1 Perinatal Definition II Perinatal Definition III

All races White Black All races White Black All races White Black

Race of mother and child2

1991 . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 7.4 15.7 12.8 10.7 23.9 11.9 9.9 22.1

1990 . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 7.7 16.4 13.3 11.1 24.7 12.3 10.2 22.9

1989 . . . . . . . . . . . . . . . . . . . . . . . . . 9.6 8.2 16.8 13.7 11.5 24.9 12.6 10.6 23.0

1988 . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 8.3 17.1 13.7 11.6 24.9 12.7 10.7 23.2

1987 ......................... 10.0 8.6 17.5 14.1 12.0 25.2 13.0 11.1 23.4

1986 ......................... 10.3 9.0 17.6 14.3 12.4 24.9 13.2 11.4 23.2

1985 ......................... 10.7 9.5 17.9 14.7 12.9 25.3 13.6 11.9 23.5

1984 . . . . . . . . . . . . . . . . . . . . . . . . . 11.0 9.8 17.9 15.1 13.3 25.1 14.0 12.3 23.4

1983 . . . . . . . . . . . . . . . . . . . . . . . . . 11.5 10.2 18.7 15.6 13.7 26.5 14.5 12.6 24.6

1982 ......................... 12.3 10.9 19.7 16.4 14.5 27.5 15.2 13.4 25.4

1981 ......................... 12.6 11.2 20.0 16.9 14.9 27.8 15.6 13.8 25.6

1980 ......................... 13.2 11.8 21.3 17.5 15.4 29.1 16.1 14.2 26.8

1979 ......................... 13.8 12.4 21.7 18.1 16.0 29.7 16.7 14.7 27.5

1978 ......................... 14.6 12.9 23.3 19.0 16.6 31.6 17.5 15.3 29.3

1977 ......................... 15.4 13.8 24.0 19.6 17.3 32.2 18.1 16.0 29.5

1976 ......................... 16.7 15.0 26.5 21.1 18.7 34.4 19.6 17.3 31.7

1975 ......................... 17.7 15.9 27.6 22.1 19.6 35.6 20.5 18.2 32.9

1974 ......................... 18.9 17.2 28.3 23.5 21.1 36.7 21.9 19.7 34.1

1973 ......................... 20.1 18.2 30.0 24.9 22.3 38.9 23.4 20.9 36.5

1972 ......................... 21.2 19.2 32.1 26.0 23.1 41.1 24.5 21.9 38.5

1971 ......................... 21.7 19.8 32.5 27.3 24.4 43.0 25.9 23.2 40.7

1970 ......................... 23.0 20.9 34.9 28.9 25.8 46.0 27.4 24.6 43.6

Race of child3

1990 . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 7.8 15.7 13.3 11.2 23.7 12.3 10.3 22.0

1989 . . . . . . . . . . . . . . . . . . . . . . . . . 9.6 8.3 16.2 13.7 11.6 24.0 12.6 10.7 22.3

1988 . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 8.4 16.5 13.7 11.7 24.1 12.7 10.8 22.4

1987 ......................... 10.0 8.7 16.9 14.1 12.1 24.4 13.0 11.1 22.7

1986 ......................... 10.3 9.1 17.0 14.3 12.5 24.1 13.2 11.5 22.5

1985 ......................... 10.7 9.6 17.4 14.7 13.0 24.5 13.6 12.0 22.7

1984 . . . . . . . . . . . . . . . . . . . . . . . . . 11.0 9.9 17.4 15.1 13.4 24.4 14.0 12.4 22.8

1983 . . . . . . . . . . . . . . . . . . . . . . . . . 11.5 10.3 18.2 15.6 13.8 25.7 14.5 12.7 24.0

1982 ......................... 12.3 11.0 19.1 16.4 14.6 26.7 15.2 13.5 24.7

1981 ......................... 12.6 11.3 19.4 16.9 15.0 27.1 15.6 13.8 25.0

1980 ......................... 13.2 11.9 20.7 17.5 15.6 28.3 16.1 14.3 26.1

1979 ......................... 13.8 12.5 21.1 18.1 16.1 28.9 16.7 14.8 26.8

1978 ......................... 14.6 13.0 22.7 19.0 16.7 30.8 17.5 15.4 28.6

1977 ......................... 15.4 13.9 23.5 19.6 17.4 31.5 18.1 16.1 28.9

1976 ......................... 16.7 15.1 25.8 21.1 18.8 33.6 19.6 17.4 31.0

1975 ......................... 17.7 16.0 26.9 22.1 19.7 34.8 20.5 18.3 32.2

1974 ......................... 18.9 17.3 27.8 23.5 21.2 36.0 21.9 19.8 33.5

1973 ......................... 20.1 18.3 29.5 24.9 22.4 38.3 23.4 21.0 35.9

1972 ......................... 21.2 19.3 31.5 26.0 23.3 40.4 24.5 22.0 37.9

1971 ......................... 21.7 19.8 32.0 27.3 24.5 42.4 25.9 23.3 40.2

1970 ......................... 23.0 21.0 34.5 28.9 25.9 45.4 27.4 24.6 43.0

1969 ......................... 23.9 21.8 - - - 29.3 26.2 - - - 27.8 25.0 - - -

1968 ......................... 25.8 23.5 - - - 31.4 28.1 - - - 30.0 26.9 - - -

1967 ......................... 26.2 23.7 - - - 31.6 28.2 - - - 30.1 26.8 - - -

1966 ......................... 26.9 24.3 - - - 32.4 28.8 - - - 30.8 27.5 - - -

1965 ......................... 27.6 25.0 - - - 33.3 29.6 - - - 31.5 28.1 - - -

1964 ......................... 28.0 25.2 - - - 33.7 29.8 - - - 31.9 28.4 - - -

19634 ........................ 27.9 25.3 - - - 33.5 29.9 - - - 31.7 28.4 - - -

19624 ........................ 28.1 25.7 - - - 33.7 30.4 - - - 31.9 28.9 - - -

1961 ......................... 28.3 25.9 - - - 34.0 30.6 - - - 32.1 29.0 - - -

1960 ......................... 28.6 26.2 - - - 34.3 30.9 - - - 32.3 29.3 - - -

1959 ......................... 28.8 26.3 - - - 34.6 31.2 - - - 32.5 29.5 - - -

1958 ......................... 29.3 26.7 - - - 35.4 31.9 - - - 33.1 30.0 - - -

1957 ......................... 28.8 26.5 - - - 34.8 31.6 - - - 32.5 29.7 - - -

1956 ......................... 28.9 26.6 - - - 34.8 31.6 - - - 32.6 29.8 - - -

1955 ......................... 29.7 27.4 - - - 35.6 32.4 - - - 33.5 30.6 - - -

1954 ......................... 29.8 27.5 - - - 35.9 32.8 - - - 33.6 30.9 - - -

1953 ......................... 30.6 28.3 - - - 36.7 33.6 - - - 34.3 31.6 - - -

See footnotes at end of table.

11
Table 1. Perinatal mortality rates for perinatal definitions I, II, and III by race: United States, 1950–91—Con.

[Perinatal Definition I includes infant deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 28 weeks or more; Perinatal Definition

II includes infant deaths under 28 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more; Perinatal Definition III includes infant

deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more. Rates per 1,000 live births and fetal deaths in specified

group]

Year

Perinatal Definition I1 Perinatal Definition II Perinatal Definition III

All races White Black All races White Black All races White Black

Race of child3—Con.

1952 ......................... 31.1 28.7 - - - 37.4 34.1 - - - 34.9 32.0 - - -

1951 ......................... 31.8 29.4 - - - 38.1 35.0 - - - 35.6 32.8 - - -

1950 ......................... 32.5 30.1 - - - 39.0 35.8 - - - 36.4 33.6 - - -

1Figures for gestational age not stated are distributed for fetal deaths; see Technical notes.

2Fetal deaths and live births, by race of mother; infant deaths by race of child.

3Fetal deaths by race of fetus; live births and infant deaths, by race of child.

4Figures by race exclude data for residents of New Jersey; see Technical notes.

12
Table 2. Perinatal mortality rates by specified Hispanic origin and race for non-Hispanic origin: Total of 31 States, 1989, and 36 States

and the District of Columbia, 1990 and 1991

[Perinatal Definition I includes infant deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 28 weeks or more; Perinatal Definition

II includes infant deaths under 28 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more; Perinatal Definition III includes infant

deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more; see Technical notes. Fetal deaths and live births based

on race and Hispanic origin of mother; infant deaths based on race and Hispanic origin of child; see Technical notes. Rates per 1,000 live births and specified fetal

deaths]

Year

All

origins1

Hispanic Non-Hispanic

Total Mexican

Puerto

Rican Cuban

Other

Hispanic2 Total3 White Black

Perinatal Definition I

1991 . . . . . . . . . . . . . . . . . . . . 8.7 7.9 7.8 8.2 7.7 8.4 8.7 7.1 15.6

1990 . . . . . . . . . . . . . . . . . . . . 9.1 8.5 8.4 9.5 8.4 8.7 9.0 7.5 15.9

1989 . . . . . . . . . . . . . . . . . . . . 9.5 9.0 8.5 10.1 10.1 10.5 9.3 7.9 16.0

Perinatal Definition II

1991 .................... 12.7 11.0 10.7 12.2 11.5 12.1 12.7 10.3 23.4

1990 .................... 13.1 11.5 11.2 13.3 12.8 12.4 13.1 10.8 23.7

1989 .................... 13.4 12.1 11.3 13.9 14.0 14.5 13.3 11.1 23.4

Perinatal Definition III

1991 . . . . . . . . . . . . . . . . . . . . 11.7 10.2 9.8 11.3 10.6 11.5 11.7 9.5 21.6

1990 .................... 12.1 10.7 10.3 12.4 11.7 11.6 12.1 9.9 22.0

1989 .................... 12.3 11.2 10.5 13.1 13.2 13.4 12.2 10.1 21.6

1Figures for origin not stated included in ‘‘all origins’’ but not distributed among origins.

2Includes Central and South American and other and unknown Hispanic.

3Includes races other than white and black.

13
Table 3. Perinatal mortality rates for perinatal definitions I, II, and III by race: United States, each State, and the District of Columbia,

1989–91 combined

[Perinatal Definition I includes infant deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 28 weeks or more; Perinatal Definition

II includes infant deaths under 28 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more; Perinatal Definition III includes infant

deaths under 7 days of age and fetal deaths with stated or presumed period of gestation of 20 weeks or more. Rates per 1,000 live births and fetal deaths in specified

group]

Area and race

Perinatal Definition I1 Perinatal Definition II Perinatal Definition III

All

races White Black

All

races White Black

All

races White Black

Rates2

United States . . . . . . . . . . . . . . . . . . . . 9.1 7.8 16.3 13.3 11.1 24.5 12.2 10.2 22.7

Alabama . . . . . . . . . . . . . . . . . . . . . . . 11.5 8.9 16.4 17.3 13.1 25.4 16.0 12.1 23.4

Alaska . . . . . . . . . . . . . . . . . . . . . . . . 6.1 6.0 * 9.5 8.5 13.1 8.4 7.8 12.5

Arizona . . . . . . . . . . . . . . . . . . . . . . . 7.8 7.4 16.8 11.0 10.5 23.1 9.9 9.5 20.8

Arkansas . . . . . . . . . . . . . . . . . . . . . . 8.9 7.4 13.7 12.8 10.6 20.0 11.6 9.5 18.2

California . . . . . . . . . . . . . . . . . . . . . . 8.2 7.7 15.3 11.3 10.6 22.2 10.4 9.8 20.3

Colorado . . . . . . . . . . . . . . . . . . . . . . 8.2 7.8 15.8 11.9 11.2 23.7 11.0 10.4 21.3

Connecticut . . . . . . . . . . . . . . . . . . . . . 8.9 7.7 16.9 12.9 11.1 25.0 12.3 10.6 23.7

Delaware . . . . . . . . . . . . . . . . . . . . . . 11.4 9.2 17.9 14.7 12.1 23.1 13.7 11.1 21.8

District of Columbia ................ 21.2 10.4 25.2 28.6 13.5 34.2 26.9 11.9 32.2

Florida . . . . . . . . . . . . . . . . . . . . . . . . 9.9 7.8 16.8 14.3 11.2 24.3 13.2 10.4 22.6

Georgia . . . . . . . . . . . . . . . . . . . . . . . 11.8 8.4 17.8 19.5 13.6 30.2 18.2 12.5 28.3

Hawaii . . . . . . . . . . . . . . . . . . . . . . . . 6.9 6.6 10.1 11.5 11.6 20.6 10.6 11.0 19.1

Idaho . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 8.4 * 12.1 11.9 * 11.3 11.1 *

Illinois ........................ 10.5 8.2 18.6 14.6 11.5 25.8 13.3 10.5 23.6

Indiana . . . . . . . . . . . . . . . . . . . . . . . 9.7 8.9 17.0 13.2 11.9 24.0 12.2 11.0 22.4

Iowa . . . . . . . . . . . . . . . . . . . . . . . . . 7.9 7.5 19.1 11.2 10.7 26.3 10.3 9.8 23.9

Kansas . . . . . . . . . . . . . . . . . . . . . . . 7.5 7.1 13.0 10.6 9.8 20.1 9.7 9.0 17.9

Kentucky . . . . . . . . . . . . . . . . . . . . . . 8.5 8.0 13.2 12.5 11.6 21.4 11.5 10.6 19.5

Louisiana ...................... 10.6 7.9 14.6 15.0 11.0 20.7 13.7 10.1 19.1

Maine . . . . . . . . . . . . . . . . . . . . . . . . 7.2 7.2 * 9.9 9.9 * 9.2 9.2 *

Maryland . . . . . . . . . . . . . . . . . . . . . . 9.4 6.8 15.4 14.1 10.1 23.3 13.0 9.2 21.8

Massachusetts . . . . . . . . . . . . . . . . . . . 7.5 6.9 13.5 10.7 9.8 20.4 9.8 9.0 18.9

Michigan . . . . . . . . . . . . . . . . . . . . . . 8.9 7.0 16.2 12.3 9.6 22.4 11.2 8.8 20.2

Minnesota . . . . . . . . . . . . . . . . . . . . . . 7.5 7.1 16.7 10.4 9.8 24.6 9.7 9.2 21.8

Mississippi . . . . . . . . . . . . . . . . . . . . . 11.7 8.1 15.7 17.7 11.2 24.7 16.6 10.3 23.3

Missouri . . . . . . . . . . . . . . . . . . . . . . . 8.9 7.8 14.5 12.5 10.6 21.9 11.4 9.6 20.0

Montana . . . . . . . . . . . . . . . . . . . . . . . 8.1 7.3 * 11.8 11.0 * 10.9 10.2 *

Nebraska . . . . . . . . . . . . . . . . . . . . . . 7.6 7.0 15.3 11.0 10.3 21.3 10.0 9.4 19.1

Nevada . . . . . . . . . . . . . . . . . . . . . . . 7.8 7.3 13.8 12.1 11.0 23.4 11.1 10.2 19.9

New Hampshire . . . . . . . . . . . . . . . . . . 7.6 7.6 * 10.4 10.3 * 9.8 9.7 *

New Jersey . . . . . . . . . . . . . . . . . . . . . 9.4 7.5 17.3 13.9 11.0 26.1 13.0 10.2 24.6

New Mexico . . . . . . . . . . . . . . . . . . . . 6.9 6.8 13.4 9.4 9.2 18.8 8.2 8.0 15.2

New York . . . . . . . . . . . . . . . . . . . . . . 10.4 8.7 17.5 16.6 13.6 28.5 15.5 12.7 26.7

North Carolina ................... 10.9 8.3 17.0 15.7 11.7 25.1 14.6 10.8 23.5

North Dakota . . . . . . . . . . . . . . . . . . . . 8.1 8.0 * 11.5 11.2 * 10.5 10.2 *

Ohio . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 8.2 15.7 13.1 11.4 22.3 12.1 10.5 20.8

Oklahoma . . . . . . . . . . . . . . . . . . . . . . 8.7 8.3 12.8 12.7 11.8 20.3 11.5 10.7 18.7

Oregon . . . . . . . . . . . . . . . . . . . . . . . 6.9 6.9 13.6 10.2 10.1 21.3 9.4 9.3 19.5

Pennsylvania . . . . . . . . . . . . . . . . . . . . 9.8 8.5 17.6 15.2 13.0 27.7 14.2 12.2 25.7

Rhode Island . . . . . . . . . . . . . . . . . . . . 8.8 8.6 14.9 12.8 12.5 21.0 11.8 11.5 19.5

South Carolina . . . . . . . . . . . . . . . . . . . 11.9 8.6 17.3 17.8 12.5 26.2 16.5 11.5 24.3

South Dakota . . . . . . . . . . . . . . . . . . . 8.9 8.0 * 11.5 10.1 * 10.6 9.3 *

Tennessee . . . . . . . . . . . . . . . . . . . . . 9.5 7.7 15.2 12.2 9.7 20.3 10.9 8.8 17.9

Texas . . . . . . . . . . . . . . . . . . . . . . . . 8.1 7.2 13.8 11.5 10.2 19.8 10.5 9.3 18.3

Utah . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 6.0 * 9.2 9.2 * 8.4 8.3 *

Vermont . . . . . . . . . . . . . . . . . . . . . . . 6.4 6.4 * 9.7 9.6 * 9.0 8.9 *

Virginia . . . . . . . . . . . . . . . . . . . . . . . 9.8 7.5 17.0 15.5 11.9 27.0 14.4 11.1 25.1

Washington . . . . . . . . . . . . . . . . . . . . . 6.8 6.5 14.9 9.9 9.4 22.1 9.0 8.6 20.4

West Virginia . . . . . . . . . . . . . . . . . . . . 9.5 9.2 16.7 13.8 13.4 25.2 12.6 12.2 23.6

Wisconsin . . . . . . . . . . . . . . . . . . . . . . 8.0 7.4 13.4 11.2 10.2 20.6 10.3 9.3 19.4

Wyoming . . . . . . . . . . . . . . . . . . . . . . 8.9 8.8 * 11.7 11.6 * 11.0 11.0 *

1Figures for gestational age not stated are distributed for fetal deaths; see Technical notes.

2Fetal deaths and live births by race of mother; infant deaths by race of child.

14
Table 4. Trends in the international ranking of perinatal mortality: 1950–90

[Rank is based on Perinatal Definition I rates. Perinatal Definition I includes infant deaths under 7 days of age and fetal deaths with stated or presumed period of

gestation of 28 weeks or more. Rankings are based on the latest data available for countries or geographic areas with at least 1 million population and with ‘‘complete’’

counts of live births and infant deaths as indicated in the United Nations: Demographic Yearbook, 1991. Ratio is the rate for the United States divided by the rate for

the country with the lowest perinatal mortality rate]

Year

All races White Black

Rank Ratio1 Rank Ratio2 Rank Ratio3

1990 . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.60 10 1.37 30 2.75

1989 . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.60 14 1.38 30 2.70

1988 . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.49 11 1.29 35 2.54

1987 . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.47 12 1.28 34 2.49

1986 . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.61 12 1.42 31 2.66

1985 . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.47 10 1.32 32 2.38

1984 . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.51 11 1.36 31 2.38

1983 . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.58 13 1.41 33 2.49

1982 . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.66 13 1.49 32 2.58

1981 . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.64 13 1.47 33 2.52

1980 . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.57 12 1.42 33 2.46

1979 . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.52 12 1.37 30 2.32

1978 . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.57 10 1.40 32 2.44

1977 . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.52 9 1.38 30 2.33

1976 . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.56 11 1.41 31 2.41

1975 . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.57 10 1.42 31 2.38

1974 . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.44 12 1.32 31 2.12

1973 . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.44 12 1.31 31 2.11

1972 . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.48 13 1.35 29 2.20

1971 . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.39 11 1.27 31 2.05

1970 . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.40 12 1.28 32 2.10

1969 . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.48 13 1.35 - - - - - -

1968 . . . . . . . . . . . . . . . . . . . . . . . . . 21 1.41 16 1.28 - - - - - -

1967 . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.39 13 1.26 - - - - - -

1966 . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.43 14 1.29 - - - - - -

1965 . . . . . . . . . . . . . . . . . . . . . . . . . 21 1.52 15 1.37 - - - - - -

1964 . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.48 15 1.33 - - - - - -

1963 . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.47 13 1.33 - - - - - -

1962 . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.43 11 1.31 - - - - - -

1961 . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.42 8 1.30 - - - - - -

1960 . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.38 9 1.27 - - - - - -

1959 . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.40 8 1.28 - - - - - -

1958 . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.39 6 1.27 - - - - - -

1957 . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.27 5 1.17 - - - - - -

1956 . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.30 4 1.19 - - - - - -

1955 . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.21 4 1.12 - - - - - -

1954 ......................... 7 1.23 3 1.13 - - - - - -

1953 ......................... 8 1.21 4 1.12 - - - - - -

1952 ......................... 6 1.15 2 1.06 - - - - - -

1951 ......................... 3 1.15 3 1.06 - - - - - -

1950 ......................... 3 1.17 3 1.08 - - - - - -

1Ratio of U.S. rate for all races divided by the rate for the country with the lowest perinatal rate. The countries are as follows: Norway (1950–2, 1954), Czechoslovakia (1953, 1955–63), Bulgaria

(1964–5), Sweden (1966–73, 1975–77, 1979, 1981, 1983–85), Denmark (1974), Finland (1978, 1980, 1982, 1986–87), and Japan (1988–90).

2Ratio of U.S. rate for the white population divided by the rate for the country with the lowest perinatal rate.

3Ratio of U.S. rate for the black population divided by the rate for the country with the lowest perinatal rate.

15
Appendix

Contents

Technical notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Sources of data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Hispanic origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

International ranking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Quality of data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Computation of rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

State maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

16
Appendix

Technical notes

Sources of data

Counts of fetal deaths are based on data from reports of

fetal deaths; counts of infant deaths are based on certificates of

death; and counts of live births are based on information from

certificates of live birth. For detailed information on the

processing, classification, and tabulation of these events, see

the technical appendixes of Vital Statistics of the United

States, Volume I, Natality (14) and Volume II, Mortality (15).

In the Ninth Revision, International Classification of

Diseases (ICD–9), the World Health Organization (WHO)

recommends that ‘‘national perinatal statistics should include

all fetuses and infants delivered weighing at least 500 grams

(or when birthweight is unavailable, the corresponding gestational age (22 weeks) or body length (25 cm crown-heel)),

whether alive or dead. . . .’’ It further recommends that ‘‘countries should present, solely for international comparisons,

‘standard perinatal statistics’ in which both the numerator and

denominator of all rates are restricted to fetuses and infants

weighing 1,000 grams or more (or, where birthweight is

unavailable, the corresponding gestational age (28 weeks) or

body length (35 cm crown-heel)).’’ Because birthweight and

gestational age are not reported on the death certificate in the

United States, the National Center for Health Statistics (NCHS)

was unable to adopt these definitions. Instead, NCHS uses

three definitions of perinatal mortality: Perinatal Definition I is

generally used for international comparisons, Perinatal Definition II, and Perinatal Definition III. These definitions were

developed to address WHO and Public Health Conference on

Records and Statistics recommendations for perinatal statistics.

Classification of data

Period of gestation—Period of gestation is the number of

completed weeks elapsed between the first day of the last

normal menstrual period (LMP) and the date of delivery. The

first day of the last normal menstrual period is used as the

initial date because it can be more accurately determined than

the date of conception, which usually occurs 2 weeks after

LMP. Data on period of gestation are computed from information on ‘‘date of delivery’’ and ‘‘date last normal menses

began.’’ If ‘‘date last normal menses began’’ is not on the

record or the calculated gestation falls beyond a duration

considered biologically plausible, the ‘‘physician’s estimate of

gestation’’ is used.

To improve data quality, beginning with data for 1989,

NCHS instituted a new computer edit to check for consistency

between gestation and birthweight to improve data quality

(15). If LMP gestation is inconsistent, the physician’s estimate

is used; if both are inconsistent with birthweight, LMP gestation is used and birthweight is assigned to unknown. When the

period of gestation is reported in months on the report, it is

allocated to gestational intervals in weeks.

All areas reported LMP in 1989 and 1990 except Puerto

Rico. All areas reported physician’s estimate of gestation

except California, the District of Columbia, Louisiana, Maryland, and Oklahoma. Nebraska also was excluded because of

the large proportion of unknown. In 1991 data on reported

physician’s estimate of gestation became available for the

District of Columbia and Nebraska.

Gestation not stated—A fetal death with gestation not

stated is presumed to be at 20 weeks of gestation or more if (a)

the death occurred in a State that requires reporting of all fetal

deaths of gestational age 20 weeks or more, or if (b) the fetus

weighed 500 grams or more in a State that requires reporting

of all fetal deaths regardless of gestational age. For Perinatal

Definition I, fetal deaths with gestation not stated but presumed to be at 20 weeks of gestation or more are allocated to

28 weeks of gestation or more according to the proportion of

fetal deaths with stated gestational age that falls into that

category. For perinatal definitions II and III, fetal deaths with

presumed gestation of 20 weeks or more are included with

those of stated gestation of 20 weeks or more.

Race—Beginning with the 1989 data year, NCHS changed

the method of tabulating live birth and fetal death data by race

from race of child to race of mother. As in previous years, race

for infant deaths is tabulated by the race of the decedent. This

results in perinatal mortality rates for 1989 and later that are

not comparable with those published for previous years. In

this report, data are provided for race of mother and race of

child when available.

The change to race of mother for fetal deaths and live

births affects perinatal mortality rates because these rates are

calculated by dividing the number of fetal deaths and live

births by the number of fetal deaths and live births. Consequently, the fetal death component of the numerator of a

perinatal rate is affected, and the fetal and live-birth components of the denominator of a perinatal rate are affected by the

change from using race of child to using race of mother.

As noted in detail in the technical appendixes to Vital

Statistics of the United States (14,15), data on live births and

17
fetal deaths are tabulated by the race of the mother beginning

with 1989. When the race of the mother is unknown, the race

of the mother is assigned to the father’s race; when information for both parents is missing, the race of the mother is

assigned to the specific race of the mother of the preceding

record with known race. In previous years, birth and fetal

death tabulations were calculated by race of child as determined statistically by an algorithm based on information

reported for the mother and father. If the parents were of

different races, the following rules applied: (a) When only one

parent was white, the fetus or infant was assigned to the other

parent’s race. (b) When neither parent was white, the fetus or

infant was assigned to the father’s race with one exception—If

the mother was Hawaiian or part-Hawaiian, the fetus or infant

was classified as Hawaiian.

When race of one parent was missing or ill-defined, the

race of the other determined that of the fetus or infant. When

the race of both parents was missing, the race of the fetus or

infant was allocated according to the specific race of the fetus

or infant on the preceding record. Further details on the

change in tabulation from race of child to race of mother are

provided in a separate report (16).

New Jersey, 1962–64—New Jersey omitted the race item

from its certificates and reports of live birth, death, and fetal

death in the beginning of 1962. The item was restored during

the latter part of 1962. However, the certificate revision

without the race item was used for most of 1962 as well as

most of 1963. Therefore, figures by race for 1962 and 1963

exclude New Jersey. Adjustments made in vital statistics to

account for the omission of the race item in New Jersey for

part of the certificates filed during 1962–64 are described in

the Technical Appendix from Vital Statistics of the United

States for each of those data years.

Hispanic origin

Perinatal mortality data for the Hispanic-origin population

are based on fetal deaths to mothers of Hispanic origin who

were residents of those States and the District of Columbia

that included items on the certificates and reports of live birth,

death, and fetal death to identify Hispanic or ethnic origin of

mother. The table in this report further restricts the data to

States reporting the Hispanic-origin item on at least 90 percent

of records by place of occurrence. The list of States included

for each year is as follows:

1989

Alabama, Arizona, Arkansas, California, Colorado, Florida,

Georgia, Hawaii, Idaho, Illinois, Iowa, Kansas, Kentucky,

Minnesota, Mississippi, Missouri, Nebraska, Nevada, North

Carolina, Ohio, Oregon, Pennsylvania, South Carolina, South

Dakota, Tennessee, Texas, Utah, Vermont, West Virginia,

Wisconsin, and Wyoming

1990

Alabama, Alaska, Arizona, Arkansas, California, Colorado,

Delaware, District of Columbia, Florida, Georgia, Hawaii,

Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Minnesota,

Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, West

Virginia, Wisconsin, and Wyoming

1991

Alabama, Alaska, Arizona, Arkansas, California, Colorado,

Delaware, District of Columbia, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North

Carolina, North Dakota, Ohio, Oregon, Pennsylvania, South

Carolina, South Dakota, Tennessee, Texas, Utah, Virginia,

Vermont, West Virginia, Wisconsin, and Wyoming

Rates are shown each year for a reporting area that had an

item on Hispanic or ethnic origin and whose data for all three

files were at least 90 percent complete on a place-ofoccurrence basis and considered to be sufficiently comparable

to be used for analysis.

International ranking

Rankings of perinatal rates are based on the latest data

available for countries or geographic areas with at least

1 million population and with ‘‘complete’’ counts of live

births, infant deaths, and fetal deaths as indicated in the United

Nations: Demographic Yearbook, 1991 (17). For the U.S. data,

Perinatal Definition I is used to rank the rate.

For international comparison, countries provide perinatal

mortality rates that use fetal deaths at 28 weeks of gestation or

more and infant deaths of under 7 days of age. Among the

perinatal definitions used in the United States, Perinatal Definition I meets this standard. The comparability of international

perinatal rates is affected by differences in the definitions used

in the various countries around the world. With a few exceptions, all the countries use definitions of live birth and fetal

death that are consistent with the WHO definitions. In Bulgaria, the definition of a fetal death includes a length restriction of 25 centimeters in addition to the 28 weeks of gestational

period. The additional restriction would result in an undercount of fetal deaths. Germany follows the alternate WHO

recommendation to restrict fetal deaths to those of 1,000

grams or more. In the German Democratic Republic, definition of fetal deaths also includes deliveries of 1,000 grams or

more that breathe or have a heart beat but do not have both

signs of life. This difference in definition results in an undercount of fetal deaths (18).

An additional factor that affects comparability is differences in the reporting requirements for fetal deaths occurring

before 28 weeks of gestation. Research has shown that earlier

mandatory reporting results in more complete data for subsequent gestational periods. A comparison of the distribution of

fetal deaths by gestation according to the reporting requirements indicates that underreporting occurs at the lower limit of

the requirement. Consequently, areas with a reporting requirement have substantially fewer fetal deaths reported near the

lower limit of the requirement than areas requiring reporting

of all fetal deaths (15,19).

However, in most countries, no requirement exists for

reporting these earlier fetal deaths. Consequently, reporting of

18
fetal deaths is not as complete for the countries that do not

require an earlier reporting period. The countries that do

require reporting of fetal deaths at gestations earlier than 28

weeks are Japan (all fetal deaths at 12 weeks of gestation or

more), Norway (all fetal deaths at 16 weeks of gestation or

more), and the United States (all fetal deaths of 20 weeks of

gestation or more).

Quality of data

In the United States, all States have adopted laws that

require the registration of births and deaths and reporting of

fetal deaths. It is believed that over 99 percent of the births

and deaths occurring in this country are registered.

State requirements for reporting of fetal deaths vary. Most

States require reporting of fetal deaths at gestations of 20

weeks or more. There are a few that require reporting of all

fetal deaths and others that require reporting of fetal deaths at

any period if the weight is 350 grams, 400 grams, or 500

grams (15).

As discussed in the case of countries, substantial evidence

indicates that not all fetal deaths for which reporting is

required are reported. Likewise, underreporting of fetal deaths

in the United States may occur near the lower limit for States

that have a minimum gestational period requirement. Research

has found that in areas requiring the reporting of fetal deaths at

20 weeks of gestation or more, the total number reported at

20–23 weeks of gestation is lower than the number reported at

24–27 and 28–31 weeks of gestation. In contrast, in areas

requiring reporting of all fetal deaths, regardless of the period

of gestation, the number reported at 20–23 weeks of gestation

is larger than the number at 24–27 and 28–31 weeks of

gestation (15,19).

To maximize comparability of data by year and by State,

U.S. fetal death and perinatal mortality statistics are based on

fetal deaths at 20 weeks of gestation or more. In States

requiring reporting of all products weighing 500 grams or

more—New Mexico, South Dakota, and Tennessee—fetal

deaths at 20 weeks of gestation or more but weighing less than

500 grams are excluded. Beginning with 1969 fetal deaths of

not-stated gestation were excluded for States requiring reporting of all products of conception except for those with a stated

birthweight of 500 grams or more. In 1990 this rule applied to

the following States: Georgia, Hawaii, New York, Rhode

Island, and Virginia.

Variations in fetal death reporting requirements and practices have implications for comparing perinatal rates among

States. Because reporting is generally poorer near the lower

limit of the reporting requirement, States that require reporting

of all products of conception regardless of gestation are likely

to have more complete reporting of fetal deaths at 20–27

weeks of gestation than are States not requiring reporting of

all products. The larger number of fetal deaths reported by

these ‘‘all periods’’ States may result in higher perinatal rates

compared to States in which reporting is less complete.

Accordingly, reporting completeness may account, in part, for

differences among State perinatal rates, particularly differences for perinatal definitions II and III, which use data for

fetal deaths at 20–27 weeks of gestation.

Slight comparability problems in perinatal mortality ratios

also arise from the inconsistent application of the definition of

fetal death by individual reporting units (19). For example,

some live-born infants who die shortly after birth, particularly

those born prematurely who die before the umbilical cord is

severed or while the placenta is still attached, may erroneously

be reported as fetal deaths. Differences in application of the

definition of live birth and fetal death can have the effect of

increasing perinatal ratios by decreasing the number of live

births in the denominator by a small amount. Perinatal rates,

however, are not as affected by this situation because births

and fetal deaths are included in the denominator.

Another factor that may have a minor effect on comparability of perinatal rates among States involves fetal deaths with

unknown gestation. There is variation among the States in the

proportion of fetal deaths of unknown gestation. These fetal

deaths are allocated in the perinatal statistics to 20–27 weeks

of gestation and to 28 weeks of gestation or more according to

the proportion of fetal deaths with known gestation that fall

into the two categories. For example, a State that requires

reporting of all products of conception and also has a relatively high proportion of fetal deaths with unknown gestation

may have a larger proportionate share of fetal deaths allocated

to 20–27 weeks of gestation than a State that has a similar

proportion of fetal deaths with unknown gestation but which

requires reporting only for 20 weeks of gestation or more.

Computation of rates

The rates shown in this report were computed using the

following formulas.

Perinatal

Definition I

mortality

rate per

1,000 live

births and

fetal deaths

=

Number of infant deaths of under

7 days of age + number of fetal

deaths with stated or presumed

period of gestation of 28 weeks or

more during a period

Number of live births + number of

fetal deaths with stated or presumed

period of gestation of 28 weeks or

more during the same period

x 1,000

Perinatal

Definition II

mortality

rate per

1,000 live

births and

fetal deaths

=

Number of infant deaths of under

28 days of age + number of fetal

deaths with stated or presumed

period of gestation of 20 weeks or

more during a period

Number of live births + number of

fetal deaths with stated or presumed

period of gestation of 20 weeks or

more during the same period

x 1,000

Perinatal

Definition III

mortality

rate per

1,000 live

births and

fetal deaths

=

Number of infant deaths of under

7 days of age + number of fetal

deaths with stated or presumed

period of gestation of 20 weeks or

more during a period

Number of live births + number of

fetal deaths with stated or presumed

period of gestation of 20 weeks or

more during the same period

x 1,000

19
Random variation

Although the mortality data in this report except data for

1972 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 confidence 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

(approximate 95-percent confidence interval) that

N – 2 'N

and

N + 2 'N

covers the ‘‘true’’ number of events.

R – 2 R

'N

and

R + 2 R

'N

covers the ‘‘true’’ rate.

If the rate R1 corresponding to N1 events is compared with the

rate R2 corresponding to N2 events, the difference between the

two rates may be regarded as statistically significant if it

exceeds

2 ÎR1

2

N1

+

R2

2

N2

Additional information on random variation may be found

in the Technical Appendix from Vital Statistics of the United

States, Volume II, Mortality (15). An asterisk is shown in place

of a rate based on fewer than 20 deaths. These rates have a

relative standard error of 23 percent or more and therefore are

considered highly variable.

State maps

Assigning the States into the given categories on the maps

was carried out in two steps: (a) Determining whether the

State perinatal mortality rate (Perinatal Definition I) differed

significantly from the corresponding U.S. rate at the 0.05 level

of significance; (b) then grouping the State rates found to be

significantly different from the U.S. rate into the four categories: 10 highest State rates of those significantly greater than

the U.S. rate, remaining State rates significantly greater than

the U.S. rate, 10 lowest State rates of those significantly lower

than the U.S. rate, and remaining State rates significantly

lower than the U.S. rate. Depending on the number of deaths,

different procedures were used to test statistical significance

and to determine confidence intervals.

For 50 deaths or more, the standard normal Z statistic was

used to perform the significance test. For 1–49 deaths the

lower and upper 95-percent confidence limits were estimated

as described elsewhere (20). The difference between the State

and U.S. rates was determined to be statistically significant at

the 0.05 level if the rates’ respective 95-percent confidence

limits did not overlap.

20
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