Amniocentesis (am-nee-o-sen-te-sis) is an antenatal outpatient diagnostic test done in the pregnant mother to rule out the possible presence of birth defects in the fetus whereby the amniotic fluid (fluid present in the womb) is removed and tested for the various birth defects. It is usually performed between the sixteenth and twentieth week of pregnancy.

Indications for doing amniocentesis:

• Mother is above thirty-five years of age
• Mother has a previous child with birth defects
• There are relatives affected with genetic disorders
• Later in pregnancy if there is a possibility of premature delivery to check for the maturity of the lung in the baby

Procedure of amniocentesis: The position of the Fetus (unborn baby) is determined by an ultrasound. A local anesthetic is then used to numb the skin and a needle attached to a syringe is inserted through the abdomen of the mother into the amniotic sac away from the fetus to withdraw about 20-30ml of fluid. This fluid is analyzed to determine if there are any possible defects. Tests on the amniotic fluid and cells in the fluid can detect birth defects such as Down’s syndrome, Spina bifida, some forms of muscular dystrophy and metabolic disorders.

Adverse Effects: Amniocentesis is a relatively safe procedure. However there is always a risk of abortion of about 0.8-1% with this procedure. Hence it is always done in a higher center with expertise in this procedure.

Last Updated on 05-11-2004