Also known as: amniotic fluid test, AFT.

What is amniocentesis?

Amniocentesis is a medical test performed on a pregnant woman. It involves removing  fluid from the amniotic sac within the uterus. Fluid collected by this procedure can be analyzed to help diagnose certain high risk fetal conditions. This procedure can also be used as a treatment for excess amniotic fluid in pregnancy.

What happens during the procedure?

First, an ultrasound transducer is used to determine the baby’s location in the uterus. After the abdomen is cleaned, a thin, hollow needle is inserted through the abdomen and into the uterus in order to withdraw amniotic fluid. Then the needle is removed, and the fluid is taken for testing. 

Is any special preparation needed?

Preparation for amniocentesis will vary based on when during the pregnancy the test is performed. Before week 20 of the pregnancy, the woman should drink plenty of fluid and avoid urinating in order to have a full bladder for the test. After 20 weeks of pregnancy, it’s best to have an empty bladder for the procedure.

What are the risk factors?

Leaking amniotic fluid, miscarriage, injury related to the needle puncture and infection are all potential risks related to amniocentesis.

Reviewed by: Saima Aftab, MD

This page was last updated on: March 26, 2019 12:28 PM