Chorion Villus Biopsy also known as Chorionic villus sampling (CVS) is usually performed during pregnancy to determine if an unborn child is at the risk of any congenital disease. Not all pregnant ladies need to have CVS test but when there is a possibility that a baby may have any abnormal condition CVS test is recommended by Gynaecologist. The genetic information present in the tissues can be used to find out if any biochemical or abnormal genetic condition such as Down Syndrome, Cystic Fibrosis or Tay-Sachs Disease is present in the developing fetus.