Amniocentesis is one prenatal procedure that may be administered during pregnancy to detect certain abnormalities of the fetus. A sample of fluid is removed from the amniotic sac, which is the bag of fluid that surrounds the fetus. Amniocentesis can detect or rule out certain congenital, genetic or biochemical disorders in the developing child.

During the test, a thin needle is inserted into the abdomen and a small portion of fluid is withdrawn. The fluid is then sent to a laboratory for analysis.

Amniocentesis can reveal whether the fetus has Down syndrome, neural tube defects (e.g., spina bifida), cystic fibrosis (metabolic disorder that causes the lungs, intestines and pancreas to become clogged with thick mucus), blood disorders, infections and other problems.

Amniocentesis is typically a safe procedure for the mother and fetus. However, complications can occur, such as preterm delivery and skeletal deformities. In rare cases, death of the fetus may result.

Although amniocentesis is suggested to women aged 35 years and older and those whose fetuses may be at high risk for certain disorders, it remains an elective procedure. Women should weigh the pros and cons of amniocentesis and discuss their concerns with a physician (obstetrician-gynecologist).