During this outpatient procedure, a doctor withdraws amniotic fluid from a pregnant woman's uterus. This is the fluid that surrounds the developing baby. It contains cells and chemicals related to the baby's development.
Amniocentesis is most commonly performed as a diagnostic test. The fluid is examined for signs of genetic and chromosomal abnormalities in the baby. It can be used to diagnose conditions such as Down syndrome, cystic fibrosis, sickle cell disease and Tay Sachs disease. This type of test may be recommended as an option for a woman who is at a high risk for bearing a child with these disorders.
Amniocentesis may also be performed for other reasons. It can be used to determine if the baby's lungs have developed enough for birth. It can be used to determine if the baby has an infection. It can also be used to reduce the amount of amniotic fluid in the womb.
The procedure begins with an ultrasound exam of the patient's abdomen. This helps the physician see the baby's position within the womb. Next, the patient's abdomen is cleansed and sanitized. Using the ultrasound for guidance, the physician inserts a needle through the abdomen and into the uterus. Amniotic fluid is carefully withdrawn from this sac.
When the procedure is complete, the needle is removed and the abdomen is bandaged. The patient and the baby's health may be monitored for a short time before release. Some cramping or vaginal bleeding may occur immediately after an amniocentesis. Results from an analysis of amniotic fluid may take days or weeks.