Amniocentesis is a procedure used to sample the amniotic fluid around the baby while in the uterus. This procedure is typically done during or after the fifteenth week of pregnancy. Amniocentesis can be used to determine if the baby may have a problem with too many or too few chromosomes, to determine if the baby may have contracted a viral or bacterial infection, or, later in the pregnancy, to determine if the baby's lungs are mature enough to deliver the baby.
Amniocentesis involves placing a needle through the skin on the mother's abdomen into the uterus and collecting a small sample of the amniotic fluid around the baby while continuously watching with the ultrasound. Typically, amniocentesis is performed in the doctor's office.
The risk of an amniocentesis is the risk of infection and risk of pregnancy loss. Nationally, this risk is quoted as one pregnancy loss for every 200 to 1,000 amniocenteses performed. Many studies have shown that the main key to safety in amniocentesis is having the amniocentesis done by someone who has experience performing amniocentesis. In our hands, we find this to be a safe and useful procedure in situations where there are concerns about the baby and where the results may help to manage the pregnancy.
When performed by an experienced physician, amniocentesis has a low risk for procedure related miscarriage and does not increase the risk for birth defects in the fetus.