What is amniocentesis?

Amniocentesis is a procedure that takes a small amount of amniotic fluid out of a pregnant woman’s belly. Amniotic fluid is the liquid that surrounds the fetus inside the mother’s uterus (womb).


Why is amniocentesis done?

Amniocentesis is done to get a sample of amniotic fluid. The amniotic fluid is tested to get more information about the health of the fetus.

The two most common reasons amniotic fluid is tested are to find out if the fetus:

 Has a genetic problem, such as Down syndrome. This might be done if another test, such as an ultrasound or blood test on the mother, has shown that something might be wrong with the fetus.

 Will be able to breathe on its own if it is born before the due date


When is amniocentesis done?

The test can be done any time after 15 weeks of pregnancy. The timing depends on why the amniotic fluid is being tested.

How is amniocentesis done? — Here are the main steps:

 A doctor will do an ultrasound so he or she can see moving pictures of your uterus, your fetus, and the amniotic fluid on a screen (like a TV).

 This doctor or another doctor will watch the screen as he or she inserts a needle into your belly and then into the amniotic fluid .

 The doctor will use the needle to take out a small amount of fluid. The test usually takes about 1 to 2 tablespoons of fluid.

 The fluid will be sent to a lab for tests.


Does amniocentesis have any risks?

Yes. Problems are rare, but they can happen. Risks include:

  •  Leaking of amniotic fluid. Sometimes, this can lead to infection, which can lead to miscarriage early in pregnancy, or preterm labor and preterm birth later in pregnancy. (Preterm birth means the baby is born before 37 weeks of pregnancy.)
  •  The needle can touch the baby, which in rare cases causes an injury
  •  Blood from the placenta can leak into your own bloodstream. (The placenta is the organ that brings the baby nutrients and oxygen and carries away waste.) This can cause problems for later pregnancies.


Should I be worried about symptoms after the procedure?

That depends on what symptoms you have and how bad they are. After amniocentesis, it is normal to have mild cramps in your belly for a short time.

Call your doctor if:

  •  You are bleeding or leaking fluid from your vagina
  •  You have cramps that are getting worse
  •  You have a fever higher than 100.4°F (38ºC)


What if the test shows that something is wrong with my fetus?

You should talk to a genetic counselor before and after the test. He or she can help you understand your feelings and decide what to do




Dr. Pinky Ronen, M.D.

950 Threadneedle, Suite 282

Houston, Texas 77079

713-464-4444 phone

713-465-9718 fax




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