Overview
A blood test can be performed between the 15th and 22nd weeks of the pregnancy to determine whether the baby is at risk for certain birth defects. Blood is drawn from a vein and the sample is sent to a laboratory for testing. If the test is abnormal other tests can be performed to rule out birth defects.
Review Date 3/31/2024
Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.