Amniocentesis: Answers to the Most Commonly Asked Questions
Going in for any medical procedure can be stressful. Many women find that knowing what to expect before they have their amniocentesis helps to calm their nerves.
When it's time for your procedure, you'll lie down on an exam table, and your healthcare provider will use an ultrasound to find a safe area in the amniotic sac to remove amniotic fluid. This area will be away from the baby and the placenta. Your healthcare provider will clean an area of your stomach with an antiseptic solution.
Then, using the ultrasound for guidance, your healthcare provider will insert a long, fine needle through your abdomen (stomach area) and uterus into the amniotic sac. After withdrawing a small amount of amniotic fluid -- normally 20 to 30 mL, which is an ounce or less -- the needle is removed. Your healthcare provider will then check your baby's heart rate. The entire procedure usually takes less than 45 minutes.
The amount of discomfort can vary from woman to woman, and even from pregnancy to pregnancy. You'll probably have some mild discomfort or feel a sharp pain when the needle enters your skin and again when it enters the uterus. You may also feel mild cramping or pressure during the procedure and for a few hours or a couple of days afterward.
Although it is possible to have the area numbed with a local anesthetic before the needle is inserted, the injection you'll need to get the anesthetic may be more uncomfortable than the amniocentesis itself. Most women choose not to have an anesthetic.
An amniocentesis is an outpatient procedure, which means you'll go home the same day. But you'll need to take it easy, so make sure someone is with you to drive you home and help you out when you get home. You'll want to avoid exercise, lifting anything heavy, and sexual intercourse for the rest of the day. You'll likely be able to resume your normal activities the next day, unless your healthcare provider tells you otherwise.
You might have a small amount of cramping, vaginal bleeding, or vaginal discharge immediately after the procedure, but these problems should stop quickly. Although you may experience some mild cramping for the next day or so, call your healthcare provider if you have severe cramping that lasts for several hours, a fever, or persistent vaginal discharge or bleeding, as these could be signs of a more serious problem.
The sample of amniotic fluid will be sent to a laboratory, where it will be tested. The laboratory can separate your baby's cells from the amniotic fluid, allow them to reproduce so there are enough cells for testing, and then test the cells for genetic conditions. The amniotic fluid can also be tested for a protein known as alpha fetoprotein (AFP), which can be used to check for neural tube defects. AFP levels are usually higher when a baby has a neural tube defect.
It can take the laboratory a week or two to grow enough cells for testing and to analyze the sample of amniotic fluid. Most women get their results within two weeks. If you had an amniocentesis to test whether your baby's lungs are mature enough for delivery, it will only take a few hours to get the results.