What you can expect

By Mayo Clinic Staff

Amniocentesis is usually done in an outpatient facility or the health care provider's office.

During the procedure

First, your health care provider will use ultrasound to determine the baby's exact location in your uterus. You'll lie on your back on an exam table and expose your abdomen. Your health care provider will apply a special gel to your abdomen and then use a small device known as an ultrasound transducer to show your baby's position on a monitor.

Next, your health care provider will clean your abdomen with an antiseptic. Generally, anesthetic isn't used. Most women report only mild discomfort during the procedure.

Guided by ultrasound, your health care provider will insert a thin, hollow needle through your abdominal wall and into the uterus. A small amount of amniotic fluid will be withdrawn into a syringe, and the needle will be removed. The specific amount of amniotic fluid withdrawn depends on the number of weeks the pregnancy has progressed.

You'll need to lie still while the needle is inserted and the amniotic fluid is withdrawn. You might notice a stinging sensation when the needle enters your skin, and you might feel cramping when the needle enters your uterus. The procedure usually takes about 20 to 30 minutes.

After the procedure

After the amniocentesis, your health care provider might use ultrasound to monitor your baby's heart rate. You might experience cramping or a small amount of vaginal bleeding immediately after the amniocentesis. Avoid strenuous physical activity for a day or two.

Meanwhile, the sample of amniotic fluid will be analyzed in a lab. Some results might be available within a few days. Other results might take up to four weeks.

Contact your health care provider if you have:

  • Persistent fluid leaking from your vagina
  • Heavy vaginal bleeding
  • Abdominal pain or uterine cramping that lasts more than a few hours
  • Fever
  • Redness and inflammation where the needle was inserted
  • Unusual fetal activity or a lack of fetal movement
Oct. 10, 2012