When you are about 15 weeks pregnant, your doctor may offer amniocentesis. Amniocentesis is a test that detects or rules out certain inherited disorders in a fetus. It also assesses lung maturity to see if the fetus can endure an early delivery. You can also find out the baby's gender.
Doctors generally offer amniocentesis to women with an increased risk of having a baby with particular disorders, including those who:
- Will be 35 or older when they deliver.
- Have a close relative with a disorder.
- Had a previous pregnancy or baby affected by a disorder.
- Have test results (such as a high or low alpha-fetoprotein count) that may indicate an abnormality.
Doctors also offer amniocentesis to women with pregnancy complications, such as Rh-incompatibility, that necessitate early delivery.
Update Date 8/5/2013
Updated by: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.