Amniocentesis During Pregnancy
If you are over 35 years of age at the time of conceiving or have a positive triple test (for down’s syndrome screening) or have a significant positive family history of a genetic disorder, you may be asked to undergo a procedure called amniocentesis between 15-18 weeks of pregnancy.
During pregnancy, the fetus is surrounded by a water bag which acts as a cushion for the baby. This water is mainly formed by the baby and is called the Amniotic fluid.
Amniocentesis is a procedure through which we remove a small amount of amniotic fluid from the water bag in the uterus. This fluid contains cells shed by the fetus and these cells can be analyzed in the lab to give us genetic information that we need.
The procedure usually involves getting an ultrasound done and then under constant ultrasound guidance,a needle is introduced through the mother’s abdomen into the water bag. Around 15-20 ml of fluid is removed and sent to the genetics lab so that the cells can grow and be analyzed. Early results are usually available in about 3 days a and the final reports are available by 3 weeks.
Amniocentesis is a definitive test and helps to confirm a tentative diagnosis of an abnormality previously found with other screening tests. It may also find that a fetus does not have the abnormality that was suspected.