CLEVELAND -- Cell-free fetal DNA testing is a new screening test that indicates if a woman is at increased risk of having a fetus with Down syndrome (trisomy 21), Edward syndrome (trisomy 18), and Pateau syndrome (trisomy 13).
MetroHealth Medical Center is using it on high risk women based on age, abnormal ultrasound or other factors.
With this test, a sample of the woman's blood is taken after 10 weeks of pregnancy. The test measures the relative amount of free fetal DNA in the mother's blood.
The test determines the chance that the fetus has Down syndrome, Edward syndrome, or Pateau syndrome based on the relative amount of DNA from chromosomes 21, 18, and 13.
The results are usually available within two weeks of the blood draw.
Results are estimated to be greater than 99% of all Down syndrome pregnancies and greater than 98% of all trisomy 18 pregnancies. It detects about 65% of all trisomy 13 pregnancies.
Women who are found to be at increased risk can have definitive testing with chorionic villus sampling (CVS) or amniocentesis. If they choose to have the Cell-free test and receive a positive result, amniocentesis is recommended.