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Pregnancy and Amniocentesis

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When Is Amniocentesis Performed?

If your doctor has recommended an amniocentesis, the procedure is usually scheduled between the 15th and 18th week of pregnancy.

How Accurate Is Amniocentesis?

The accuracy of amniocentesis is about 99.4%.

Amniocentesis may occasionally be unsuccessful due to technical problems, such as being unable to collect an adequate amount of amniotic fluid or failure of the collected cells to grow when cultured.

Does Amniocentesis Have Risks?

Yes. There is a small risk that an amniocentesis could cause a miscarriage (less than 1%, or approximately 1 in 200 to 1 in 400). Injury to the baby or mother, infection, and preterm labor are other potential complications that can occur, but are extremely rare.

Can I Choose Not to Have an Amniocentesis?

Yes. You will receive genetic counseling before the procedure. After the risks and benefits of amniocentesis have been thoroughly explained to you, you can choose whether or not you want to have the procedure.

What Happens During an Amniocentesis?

A small area of the abdomen is cleansed with an antiseptic to prepare for the amniocentesis. You may receive a local anesthetic (pain-relieving medication) to reduce any discomfort. The doctor first locates the position of the fetus and placenta with an ultrasound. Under ultrasound guidance, the doctor inserts a thin, hollow needle through your abdomen and uterus, and into the amniotic sac, away from the baby. A small amount of fluid (less than an ounce) is removed through the needle and sent for laboratory analysis.

You may feel minor menstrual-like cramping or discomfort during the amniocentesis or for a few hours after the procedure.

Can I Resume Normal Activities After an Amniocentesis?

After an amniocentesis, it is best to go home and relax for the remainder of the day. You should not exercise or perform any strenuous activity, lift anything over 20 pounds (including children), and you should avoid sexual relations.

You may take two Tylenol (acetaminophen) every 4 hours to relieve discomfort. The day after the procedure, you may resume all of your normal activities unless otherwise directed by your doctor.

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