Definition

Amniocentesis is an optional procedure offered to women during pregnancy in order to obtain more information about a developing fetus. A doctor uses a thin, hollow needle to remove a small sample of amniotic fluid from around the developing baby. An ultrasound exam is usually performed at the same time to help guide the needle. The fluid sample is used to look for specific types of medical problems in the fetus. Tests done on amniotic fluid obtained by amniocentesis cannot evaluate the fetus for every potential kind of problem. The information it does provide, however, is very accurate. The procedure is associated with a slightly increased chance for pregnancy loss. Women who undergo amniocentesis typically do so either to obtain reassurance about fetal well-being or, if the results are abnormal, to plan for the remainder of their prenatal care.