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## Complete Summary

#### GUIDELINE TITLE

Invasive prenatal testing for aneuploidy.

#### BIBLIOGRAPHIC SOURCE(S)

American College of Obstetricians and Gynecologists (ACOG). Invasive
prenatal testing for aneuploidy. Washington (DC): American College of
Obstetricians and Gynecologists (ACOG); 2007 Dec. 9 p. (ACOG practice
bulletin; no. 88). \[50 references\]

#### GUIDELINE STATUS

This is the current release of the guideline.

### COMPLETE SUMMARY CONTENT

 SCOPE\
 METHODOLOGY - including Rating Scheme and Cost Analysis\
 RECOMMENDATIONS\
 EVIDENCE SUPPORTING THE RECOMMENDATIONS\
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS\
 QUALIFYING STATEMENTS\
 IMPLEMENTATION OF THE GUIDELINE\
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT
CATEGORIES\
 IDENTIFYING INFORMATION AND AVAILABILITY\
 DISCLAIMER

### SCOPE

#### DISEASE/CONDITION(S)

Fetal chromosomal abnormalities (fetal aneuploidy)

#### GUIDELINE CATEGORY

Counseling\
Diagnosis\
Risk Assessment\
Screening

#### CLINICAL SPECIALTY

Medical Genetics\
Obstetrics and Gynecology\
Pediatrics

#### INTENDED USERS

Physicians

#### GUIDELINE OBJECTIVE(S)

-   To aid practitioners in making decisions about appropriate obstetric
    and gynecologic care

-   To provide clinical management guidelines for the prenatal diagnosis
    of fetal aneuploidies

#### TARGET POPULATION

All women, regardless of maternal age

#### INTERVENTIONS AND PRACTICES CONSIDERED

**Screening and Diagnosis**

1.  Risk assessment for fetal aneuploidy

2.  Invasive testing for prenatal diagnosis of fetal chromosomal
    abnormalities

    -   Amniocentesis

        -   Traditional

        -   Early (considered but not recommended)

    -   Chorionic villus sampling

    -   Cordocentesis (percutaneous umbilical blood sampling)

3.  Laboratory tests to diagnose aneuploidy

    -   Metaphase analysis of cultured amniocytes or chorionic villus
        cells

    -   Fluorescence in situ hybridization analysis

    -   Comparative genomic hybridization

4.  Ultrasonography

**Counseling**

1.  Prenatal counseling concerning risks and benefits of screening
    versus invasive diagnostic testing

2.  Counseling of women with chronic hepatitis B or C virus infections,
    or human immunodeficiency virus infection

3.  Nondirective counseling concerning pregnancy termination

#### MAJOR OUTCOMES CONSIDERED

-   Procedure-related pregnancy loss rate

-   Procedure-related complication rate

-   Risk for chromosomal abnormalities

-   Positive predictive value of diagnostic/screening tests for
    chromosomal abnormalities

### METHODOLOGY

#### METHODS USED TO COLLECT/SELECT EVIDENCE

Hand-searches of Published Literature (Primary Sources)\
Hand-searches of Published Literature (Secondary Sources)\
Searches of Electronic Databases

#### DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

The MEDLINE database, the Cochrane Library, and the American College of
Obstetricians and Gynecologists\' own internal resources and documents
were used to conduct a literature search to locate relevant articles
published between January 1985 and June 2007. The search was restricted
to articles published in the English language. Priority was given to
articles reporting results of original research, although review
articles and commentaries also were consulted. Abstracts of research
presented at symposia and scientific conferences were not considered
adequate for inclusion in this document. Guidelines published by
organizations or institutions such as the National Institutes of Health
and the American College of Obstetricians and Gynecologists were
reviewed, and additional studies were located by reviewing
bibliographies of identified articles.

#### NUMBER OF SOURCE DOCUMENTS

Not stated

#### METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Weighting According to a Rating Scheme (Scheme Given)

#### RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

Studies were reviewed and evaluated for quality according to the method
outlined by the U.S. Preventive Services Task Force:

**I** Evidence obtained from at least one properly designed randomized
controlled trial.

**II-1** Evidence obtained from well-designed controlled trials without
randomization.

**II-2** Evidence obtained from well-designed cohort or case--control
analytic studies, preferably from more than one center or research
group.

**II-3** Evidence obtained from multiple time series with or without the
intervention. Dramatic results in uncontrolled experiments also could be
regarded as this type of evidence.

**III** Opinions of respected authorities, based on clinical experience,
descriptive studies, or reports of expert committees.

#### METHODS USED TO ANALYZE THE EVIDENCE

Systematic Review

#### DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

Not stated

#### METHODS USED TO FORMULATE THE RECOMMENDATIONS

Expert Consensus

#### DESCRIPTION OF METHODS USED TO FORMULATE THE RECOMMENDATIONS

Analysis of available evidence was given priority in formulating
recommendations. When reliable research was not available, expert
opinions from obstetrician--gynecologists were used. See also the
\"Rating Scheme for the Strength of Recommendations\" field regarding
Grade C recommendations.

#### RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

Based on the highest level of evidence found in the data,
recommendations are provided and graded according to the following
categories:

**Level A** --- Recommendations are based on good and consistent
scientific evidence.

**Level B** --- Recommendations are based on limited or inconsistent
scientific evidence.

**Level C** --- Recommendations are based primarily on consensus and
expert opinion.

#### COST ANALYSIS

A formal cost analysis was not performed and published cost analyses
were not reviewed.

#### METHOD OF GUIDELINE VALIDATION

Internal Peer Review

#### DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

Practice Bulletins are validated by two internal clinical review panels
composed of practicing obstetrician-gynecologists generalists and
sub-specialists. The final guidelines are also reviewed and approved by
the American College of Obstetricians and Gynecologists (ACOG) Executive
Board.

### RECOMMENDATIONS

#### MAJOR RECOMMENDATIONS

The grades of evidence (I-III) and levels of recommendation (A-C) are
defined at the end of the \"Major Recommendations\" field.

**The following recommendation is based on good and consistent
scientific evidence (Level A)**:

-   Early amniocentesis (at less than 15 weeks of gestation) should not
    be performed because of the higher risk of pregnancy loss and
    complications compared with traditional amniocentesis (15 weeks of
    gestation or later).

**The following conclusions are based on limited or inconsistent
scientific evidence (Level B)**:

-   Amniocentesis at 15 weeks of gestation or later is a safe procedure.
    The procedure-related loss rate after midtrimester amniocentesis is
    less than 1 in 300 to 500.

-   In experienced individuals and centers, CVS procedure-related loss
    rates may be the same as those for amniocentesis.

**The following recommendation and conclusions are based primarily on
consensus and expert opinion (Level C)**:

-   Invasive diagnostic testing for aneuploidy should be available to
    all women, regardless of maternal age.

-   Patients with an increased risk of fetal aneuploidy include women
    with a previous fetus or child with an autosomal trisomy or sex
    chromosome abnormality, one major or at least two minor fetal
    structural defects identified by ultrasonography, either parent with
    a chromosomal translocation or chromosomal inversion, or parental
    aneuploidy.

-   Nondirective counseling before prenatal diagnostic testing does not
    require a patient to commit to pregnancy termination if the result
    is abnormal.

**Definitions**[:]{.underline}

**Grades of Evidence**

**I** Evidence obtained from at least one properly designed randomized
controlled trial.

**II-1** Evidence obtained from well-designed controlled trials without
randomization.

**II-2** Evidence obtained from well-designed cohort or case--control
analytic studies, preferably from more than one center or research
group.

**II-3** Evidence obtained from multiple time series with or without the
intervention. Dramatic results in uncontrolled experiments also could be
regarded as this type of evidence.

**III** Opinions of respected authorities, based on clinical experience,
descriptive studies, or reports of expert committees.

**Levels of Recommendation**

**Level A** --- Recommendations are based on good and consistent
scientific evidence.

**Level B** --- Recommendations are based on limited or inconsistent
scientific evidence.

**Level C** --- Recommendations are based primarily on consensus and
expert opinion.

#### CLINICAL ALGORITHM(S)

None provided

### EVIDENCE SUPPORTING THE RECOMMENDATIONS

#### TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The type of supporting evidence is identified and graded for each
recommendation (see \"Major Recommendations\").

### BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

#### POTENTIAL BENEFITS

Appropriate use of prenatal screening and diagnostic testing for fetal
aneuploidy

#### POTENTIAL HARMS

Procedure-related maternal and fetal complications, including pregnancy
loss, can occur with amniocentesis and chorionic villus sampling.

### QUALIFYING STATEMENTS

#### QUALIFYING STATEMENTS

These guidelines should not be construed as dictating an exclusive
course of treatment or procedure. Variations in practice may be
warranted based on the needs of the individual patient, resources, and
limitations unique to the institution or type of practice.

### IMPLEMENTATION OF THE GUIDELINE

#### DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

#### IMPLEMENTATION TOOLS

Audit Criteria/Indicators\
Foreign Language Translations\
Patient Resources

For information about
[availability](#identifying-information-and-availability), see the
\"Availability of Companion Documents\" and \"Patient Resources\" fields
below.

### INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

#### IOM CARE NEED

Staying Healthy

#### IOM DOMAIN

Patient-centeredness\
Safety\
Timeliness

### IDENTIFYING INFORMATION AND AVAILABILITY

#### BIBLIOGRAPHIC SOURCE(S)

American College of Obstetricians and Gynecologists (ACOG). Invasive
prenatal testing for aneuploidy. Washington (DC): American College of
Obstetricians and Gynecologists (ACOG); 2007 Dec. 9 p. (ACOG practice
bulletin; no. 88). \[50 references\]

#### ADAPTATION

Not applicable: The guideline was not adapted from another source.

#### DATE RELEASED

2007 Dec

#### GUIDELINE DEVELOPER(S)

American College of Obstetricians and Gynecologists - Medical Specialty
Society

#### SOURCE(S) OF FUNDING

American College of Obstetricians and Gynecologists (ACOG)

#### GUIDELINE COMMITTEE

American College of Obstetricians and Gynecologists (ACOG) Committee on
Practice Bulletins - Obstetrics

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

Not stated

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

Not stated

#### GUIDELINE STATUS

This is the current release of the guideline.

#### GUIDELINE AVAILABILITY

Electronic copies: None available

Print copies: Available for purchase from the American College of
Obstetricians and Gynecologists (ACOG) Distribution Center, PO Box 4500,
Kearneysville, WV 25430-4500; telephone, 800-762-2264, ext. 192; e-mail:
<sales@acog.org>. The ACOG Bookstore is available online at the [ACOG
Web site](http://www.acog.org/bookstore/).

#### AVAILABILITY OF COMPANION DOCUMENTS

Proposed performance measures are included in the original guideline
document.

#### PATIENT RESOURCES

The following are available:

-   Diagnosing birth defects. Atlanta (GA): American College of
    Obstetricians and Gynecologists (ACOG); 2005. Available from the
    [American College of Obstetricians and Gynecologists (ACOG) Web
    site](http://www.acog.org/publications/patient_education/bp164.cfm).

-   Screening tests for birth defects. Atlanta (GA): American College of
    Obstetricians and Gynecologists (ACOG); 2007. Available from the
    [American College of Obstetricians and Gynecologists (ACOG) Web
    site](http://www.acog.org/publications/patient_education/bp165.cfm).
    Copies are also available in Spanish.

Print copies: Available for purchase from the American College of
Obstetricians and Gynecologists (ACOG) Distribution Center, PO Box 4500,
Kearneysville, WV 25430-4500; telephone, 800-762-2264, ext. 192; e-mail:
<sales@acog.org>. The ACOG Bookstore is available online at the [ACOG
Web site](http://www.acog.org/bookstore/).

Please note: This patient information is intended to provide health
professionals with information to share with their patients to help them
better understand their health and their diagnosed disorders. By
providing access to this patient information, it is not the intention of
NGC to provide specific medical advice for particular patients. Rather
we urge patients and their representatives to review this material and
then to consult with a licensed health professional for evaluation of
treatment options suitable for them as well as for diagnosis and answers
to their personal medical questions. This patient information has been
derived and prepared from a guideline for health care professionals
included on NGC by the authors or publishers of that original guideline.
The patient information is not reviewed by NGC to establish whether or
not it accurately reflects the original guideline\'s content.

#### NGC STATUS

This NGC summary was completed by ECRI Institute on July 30, 2008. The
information was verified by the guideline developer on August 20, 2008.

#### COPYRIGHT STATEMENT

This NGC summary is based on the original guideline, which is subject to
the guideline developer\'s copyright restrictions.

### DISCLAIMER

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© 1998-2008 National Guideline Clearinghouse

Date Modified: 11/10/2008