There are a variety of prenatal tests that pregnant women undergo, including an amniocentesis. Some of them are conducted if the woman is over a certain age, and others are conducted because of certain risk factors that certain women have.

What is an Amniocentesis?

This is a procedure which detects chromosomal abnormalities or other genetic birth defects. It is a very common prenatal test done to detect chromosomal abnormalities and birth defects that can lead to Down Syndrome. This prenatal test is usually done some time between week 15 and week 18 .

What Are the Reasons for an Amniocentesis?

This procedure may be offered to women who have genetic complications, or for those over the age of 35. There is a small risk of miscarriage from this procedure, which is why it is only administered to those who are more at risk for delivering a baby with abnormalities.

How is This Procedure Administered?

This procedure involves inserting a needle through the mother's pregnant belly into the sac of amniotic fluid. This fluid is then withdrawn from the uterus to test for certain problems in the fetus. This fluid has shed skin cells from the fetus, as well as biochemical substances produced by the baby. These can be analyzed to detect any birth defects or other complications.

The mother usually lays flat on her back, and has her belly cleaned with iodine. An ultrasound should accompany the procedure to help guide the doctor as the needle is inserted. Amniotic fluid is then removed and sent to a lab for analyzing. Results should come back in approximately 3 weeks.

This procedure should only take a few minutes, and is not usually painful. An ultrasound will be used to monitor the baby’s heartbeat to make sure that the baby is not under distress.

Physical activity is discouraged for a few hours following this procedure.