Here are some of the key points form current ACOG/SMFM guidelines:
- All patients should be counseled as to the risks, benefits, and alternatives of various methods of prenatal screening and diagnostic testing, including the option of no testing. The decision about whether or not to undergo prenatal genetic testing should be an informed choice.
- When comparing cfDNA screening to other methods, it is important to note that no one screening test is superior to other screening tests in all test characteristics. Each test has relative advantages and disadvantages.
- Screens such as Integrated Screening for the general population may have advantages over cfDNA, such as the ability to screen for a broader array of conditions that may affect the fetus.
- Disadvantages of cfDNA in the low-risk population include a lower positive predictive value (PPV).
- Routine cfDNA screening for microdeletion syndromes should NOT be performed. Screening for these microdeletions has not been validated in clinical studies
- cfDNA is NOT recommended for women with multiple gestations. More studies are needed, however ACOG/SMFM note that any screening that depends on maternal blood will not be able to distinguish between fetuses.
- Parallel or simultaneous testing with multiple screening methodologies for aneuploidy should NOT be performed. This practice is not cost-effective and may lead to conflicting results
- Management decisions, including termination of the pregnancy, should NOT be based on the results of the cfDNA screening alone.
- Diagnostic testing is recommended to confirm positive cfDNA results.
- “No Call” results indicate a higher chance of a chromosome conditions, and patients who receive these results should be offered further assessment.
- When results are not reported, indeterminate, or uninterpretable, patients should be referred for genetic counseling and offered comprehensive ultrasound evaluation and diagnostic testing.
- cfDNA should not be performed solely for early sex identification of the fetus. Patients should be counseled that this screening also assesses the risk of the chromosome conditions and if that information is not desired, the screening should not be performed.
The American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine (SMFM), Committee Opinion 640, Cell-free DNA Screening for Fetal Aneuploidy (2015)
The American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine (SMFM), Committee Opinion 545, Noninvasive Prenatal testing for Fetal Aneuploidy (2012)
ACOG Practice Bulletin No. 77: screening for fetal chromosomal abnormalities (2007)