Amniocentesis

Amniocentesis is a prenatal test that helps you learn if a fetus has health problems. The test is most often done between week 15 and week 20 of pregnancy. Discuss with your healthcare provider whether amniocentesis is right for you.

Should you have amniocentesis?

If the fetus has a higher than normal chance of birth defects or other problems, you may want to have this test. The following risk factors can increase chances of fetal health problems:

  • You’re 35 or older.

  • There’s a history of inherited (genetic) problems in your family.

  • Other tests have shown that the fetus may have health problems.

How is amniocentesis done?

  • First, the fetus is located with ultrasound (sound waves that make an image on a screen).

  • A thin needle is then inserted into your belly. The healthcare provider keeps the needle from touching the fetus by watching the screen.

  • The needle is used to remove a small amount of fluid from your womb. Your body will make more fluid to replace what was taken.

  • You can go home right after the test. But you may need to take it easy for a day or so.

When to call your healthcare provider

Call your healthcare provider right away if you notice:

  • Severe pain or cramping

  • Vaginal bleeding (spotting)

  • Fever or chills

  • Fluid leaking from your vagina

Getting test results

You’ll learn your amniocentesis results in 2 weeks. Most results are normal. Even if yours aren’t, it doesn’t always mean there’s a problem. But this will depend on what your healthcare provider is looking for with amniocentesis. You and your healthcare provider can talk about other tests or special care you may want.