Understanding Amniocentesis: Risks and Benefits

Amniocentesis can be a scary procedure for an expectant mother. Prior to undergoing this procedure, it is important to understand the risks and benefits. We will be discussing amniocentesis and reviewing clinical settings in which this test may be indicated.

What is an Amniocentesis?

An amniocentesis, or amnio, is a prenatal procedure used to diagnose genetic disorders in a fetus. With this procedure, a small sample of amniotic fluid is obtained for testing. The amniotic fluid contains the cells shed by the fetus. Evaluating these cells can help diagnose genetic disorders and open neural tube defects.

When is an Amniocentesis Recommended?

An amniocentesis may be recommended if there is a family history or previous child with a genetic disease or if there is a risk of open neural tube defects, such as spina bifida. Additionally, if a woman has abnormal maternal screening, her physician may recommended an amniocentesis for further confirmation. In some cases, providers may recommended amniocentesis if the mother’s age is over 35 years by the pregnancy due date. During the third trimester of pregnancy, amniocentesis may be used to test for fetal lung maturity when there is a possibility for premature birth.

What Are the Risks of Amniocentesis?

An amniocentesis is an invasive procedure that does involve some risk to the pregnancy. There is a risk of infection and preterm labor. If an amniocentesis is done after 15 weeks of pregnancy, there is a 1% risk of miscarriage. If the amniocentesis is carried out before 15 weeks of pregnancy, there is an even higher miscarriage risk. Additionally, there can be bleeding or leaking of the amniotic fluid from the puncture site.

How Accurate is Amniocentesis?

Although there are risks involved, amniocentesis is believed to be approximately 99% accurate in detecting abnormalities.

Takeaway Message:

An amniocentesis is a prenatal test used to evaluate for fetal genetic conditions and other abnormalities. The test is invasive and does create some risk to the pregnancy, including a risk of miscarriage. It is important for patients to fully discuss the risks and benefits of an amniocentesis with their provider prior to the procedure.

Have you had an amniocentesis? Please share your experiences in the comments below.