Although the discovery of fetal DNA in the mother’s blood was made in the 1990s, it wasn’t until recent years that technological advancements have led to a commercially available test for pregnant women that can test the fetal DNA in maternal circulation.
How does it work?
Every person has 23 pairs of chromosomes, including one pair of sex chromosomes. Conditions such as Down syndrome result when there is an extra or missing chromosome. With NIPT, a blood sample is drawn from a pregnant woman as early as 10 weeks gestation. Free-floating fetal DNA found in the mother’s blood is analyzed and results are reported for Down syndrome (trisomy 21) and two other chromosome conditions called trisomy 18 and trisomy 13. NIPT may also look for fetal sex and differences in the number of sex chromosomes. NIPT does not test for all genetic conditions. Since NIPT is a screening test, CVS or amniocentesis is recommended to confirm all High Risk results.
Who should have this test?
Every pregnant woman has a risk for chromosome conditions that is specific to their age, family history, and other factors. For a personal risk assessment, you may wish to talk to your doctor about scheduling an appointment with a genetic counselor.
There are several tests available that your OBGYN may recommend, including the Harmony Prenatal Test, Counsyl, Panorama, Verifi and Maternit21. Each test has its unique strengths, so talk to your OB or a genetic counselor to find out which test is right for you based on your family history.