Amniocentesis is a procedure that, under ultrasound guidance, a small amount of amniotic fluid is withdrawn with a needle from the amniotic sac, the self-contained fluid-filled membrane surrounding the baby. The fluid is sent directly to a specialty laboratory that analyzes it. The procedure is traditionally done between the 15th and 18th week of pregnancy; however, under special circumstances, it can be done up to 36 weeks gestation. In addition to testing for an abnormal number of chromosomes, we can assess for spinal bifida and abnormalities of the abdominal wall of the baby (belly button area). We receive preliminary results in 48 hours and the final chromosome assessment in one to two weeks.
Patients who have a blood type that is Rh negative will be administered a medication called RhoGAM, to protect the baby if the baby is Rh positive. This medication is an injection that is given in either a woman’s arm or leg.
In general, you should be able to resume most daily activities after amniocentesis. You may return to work tomorrow, as long as your job does not require physical activity. The following are general guidelines for follow-up care:
For 24 hours after the procedure, please stay off your feet as much as possible. Avoid exercise, heavy lifting, intercourse, or sexual activity. Drink extra fluids.
Commonly experienced symptoms after amniocentesis include minor bruising or soreness in the area of needle insertion, and mild cramping for several hours. If you wish you may take Extra-strength Tylenol for this discomfort, as Tylenol is safe for you and your baby. Although complications are extremely rare, complications to watch for include vaginal bleeding, loss of amniotic fluid from the vagina, cramping lasting more than 3-4 hours, fever (temperature > 100.6o F), or chills. If complications occur, bed rest is advisable. We would prefer you contact the MFM physician on-call at (703) 558-6077 (24-hour answering service) if you have any of the complications listed above.
Amniocentesis is associated with a small risk of miscarriage. With our experience, the risk of miscarriage is approximately 1 in every 400 procedures.