What is an amniocentesis?

An amniocentesis is a screening that enables your health care professional to examine fetal cells in the amniotic fluid for any chromosomal abnormalities. The test is not routinely given under the age of 35, due to the small risk of miscarriage associated with this procedure—amniocentesis has a complication rate of less than 1 percent, but there is a small risk of miscarriage associated with it. If you are 35 or older when you're due to have your baby, your health care professional will likely discuss the risks of chromosomal abnormalities based on your age and recommend this test.

That's because women over 35 have a higher risk of having a baby with Down's syndrome. An amniocentesis is also recommended if you've already had a child with certain birth defects, or if you have a family or personal history that puts you at risk for certain inherited diseases. You might choose to have this test if you had abnormal blood tests that suggest there might be a problem.

Amniocentesis can diagnose numerous conditions, but only if the lab evaluating the amniotic fluid knows which tests to conduct. These tests are very expensive, so talk with your health care professional about which ones are necessary based on your history and risk factors. It can take anywhere from a few days to a few weeks to get the results.

During an amniocentesis, the doctor inserts a needle through your abdomen into the amniotic sac and removes a small amount of amniotic fluid. The doctor uses ultrasound to guide the needle and avoid inserting it into the placenta.

The test can be performed on an outpatient basis in a health care professional's office or in a hospital. It can be done at any gestational age after 11 weeks, but when it's performed for genetic studies, amniocentesis is usually done between 15 and 17 weeks.

Continue Learning about Pregnancy, Fertility and Childbirth

Can I conceive another child if I am already pregnant?
Diana MeeksDiana Meeks
In a word, yes!!  This phenomenon is called Superfetation. Such pregnancies occur when a woman conti...
More Answers
What is a term pregnancy?
HCA VirginiaHCA Virginia
In humans, singleton (one-baby) pregnancy lasts, on average, 40 weeks, or 280 days from the first da...
More Answers
How does thyroid function affect pregnancy?
Penn MedicinePenn Medicine
You should have your thyroid hormones checked by your doctor prior to pregnancy. If it is well contr...
More Answers
What Happens to Your Body When You Stop Taking Birth Control
What Happens to Your Body When You Stop Taking Birth Control What Happens to Your Body When You Stop Taking Birth Control What Happens to Your Body When You Stop Taking Birth Control What Happens to Your Body When You Stop Taking Birth Control
Just like when you first started, ditching it can cause some noticeable changes. You might be familiar with the changes that take place when you start...
Start Slideshow

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.