Amniocentesis

Amniocentesis is medical procedure in which a doctor inserts a needle through the pregnant mother’s abdominal wall and draws fluid from the amniotic sac. It is a diagnostic tool used in high-risk pregnancies, and is not a routine procedure.

How the test is performed

An ultrasound must be performed to determine the exact location of the fetus. The mother’s belly is scrubbed, and a topical anesthetic is usually applied, though some doctor’s choose to use a local anesthetic.

The doctor inserts a needle through the pregnant mother’s abdominal wall. The needle is guided through the abdominal wall into the uterus, where fluid is withdrawn from the sac surrounding the fetus.

How should you prepare for the test?

The test is typically an outpatient procedure, which does not require an overnight hospital stay. The only preparation required is the mother’s bladder must be filled for the ultrasound to be effective.

Will the test hurt?

Pain typically occurs if a local anesthetic is used, in which the pain is like any shot. There is a sharp pain followed by a minor stinging sensation as the anesthetic is injected.

As the needle enters the sac surrounding the fetus, some women indicate a mild sensation of pressure in their lower abdomen. It is also common to experience minor cramping following the procedure.

Why the test is performed

The test is used to detect many chromosomal disorders, metabolic disorders and other defects. The test can determine if the child has Down  syndrome, spina bifida (a spinal defect), anencephaly (brain is incomplete or missing), Rh incompatibility and other disorders.

Late in the pregnancy, lung maturity can be determined using this test.

Risks

There is a small risk of infection or injury to the fetus. In rare cases, the amniocentesis has caused miscarriage. Because of these risks, the doctor and patient must weigh the benefits of the tests with the risks.

Certain pregnancy symptoms  or health risk factors can lead a doctor to order this test. It is always smart to explore any alternatives with your health care provider.