AMNIOCENTESIS

General Information

DEFINITION--Removal of fluid from the amniotic sac during pregnancy.

BODY PARTS INVOLVED--Uterus; amniotic sac.

REASONS FOR SURGERY--

Laboratory examination of amniotic fluid helps diagnose abnormalities of the unborn child. The best time for amniocentesis is between the 15th and 18th weeks of pregnancy. There is ample fluid, and enough time exists to terminate the pregnancy if necessary. Amniocentesis is often done for one or more of the following reasons:

• Mother is over 35 years old. > Either parent has a chromosome abnormality. > Mother has previously had a child with a chromosome abnormality, such as Down syndrome. > Mother carries a sex-linked abnormality, and the unborn child's sex must be determined. > Unborn child's maturity or other conditions must be determined late in pregnancy.

SURGICAL RISK INCREASES WITH

• Obesity.
• Previous abdominal surgery.
• Previous infection in pelvic organs.

What To Expect

WHO OPERATES--Obstetrician-gynecologist or family doctor.

WHERE PERFORMED--Outpatient surgical facility or hospital.

DIAGNOSTIC TESTS

• Before surgery: Blood and urine studies.
• During surgery: Ultrasonography (See Glossary).
• After surgery: Laboratory examination of the amniotic fluid.

ANESTHESIA--Local anesthesia by injection. To ensure the unborn child's safety, sedatives and pain relievers will not be used.

DESCRIPTION OF OPERATION

• A local anesthetic is injected into the abdomen.
• A hollow needle is inserted through the abdominal wall into the uterus. The needle will cause temporary pain, but should not hurt more than any injection.
• A small amount of amniotic fluid is suctioned through the needle, and the needle removed.

POSSIBLE COMPLICATIONS

• Excessive bleeding.
• Surgical-wound infection.
• Unwanted abortion triggered by procedure in 1 out of 150 to 200 cases.

AVERAGE HOSPITAL STAY--None.

PROBABLE OUTCOME--More than 95% of amniocentesis tests indicate no abnormalities. Some couples at high risk want the procedure done to reduce their anxiety during pregnancy. However, normal amniocentesis results cannot guarantee a child without defects. At present there are no tests for all abnormalities.

Postoperative Care

GENERAL MEASURES---Bathe and shower as usual. You may wash the injection site gently with mild unscented soap.

MEDICATION---Medicine is usually not necessary.

ACTIVITY---No restrictions after 2 or 3 hours following the operation.

DIET---No special diet.

Call Your Doctor If

Any of the following occurs:

• Nausea and vomiting.
• Pain in the lower abdomen or shoulder.
• Vaginal bleeding.
• Signs of infection: headache, muscle aches, dizziness or a general ill feeling and fever.