Amniocentesis is the most common diagnostic procedure used to test for certain birth defects.

HOW IS AMNIOCENTESIS PERFORMED?

A small sample of amniotic fluid (the fluid surrounding the unborn baby) is withdrawn through a thin needle from the gestational sac. First, ultrasound is used to establish the position of the fetus. The needle is then carefully guided through the maternal abdomen and into the amniotic sac. Ultrasound guidance is used to optimize sampling and avoid potential contact with the fetus. A small sample (about 2 tablespoons) of fluid is obtained. If you are carrying twins the sample will need to be taken from both gestational sacs. The fetus will produce more amniotic fluid to replace the fluid taken for testing. The procedure takes approximately 2-3 minutes. Some mild, menstrual type cramping may occur during or after the procedure. We recommend at least 24 hours of rest after undergoing amniocentesis.

The sample is shipped to the laboratory for analysis. Depending on the specific testing required, results are routinely returned within 10-14 days.

There are some risks involved with the procedure. Please consult your physician for details.

WHO SHOULD AMNIOCENTSIS BE OFFERED TO?

• Any pregnant woman who will be 35 years or older at the time of delivery.
• Individuals who have a previous child with a chromosomal anomaly.
• Individuals who themselves have a chromosomal anomaly.
• Couples at risk for having a child with a genetic condition such as Tay Sachs disease, cystic fibrosis, or sickle cell disease/anemia.
• Couple with increased risk of Spina Bifida.
• Women who have had an abnormal AFP/Triple Screen/1st Trimester Screen/Quad Screen, indicating an increased risk of Down Syndrome, trisomy 18/13 or neural tube defect.
• Patients with abnormal ultrasound findings.