Amniocentesis is technique to determine sex of the developing foetus, congenital disease and metabolic disorders in foetus. The technique is used for the analysis of amniotic fluid, which contain somatic cells of foetus, and proteins, especially enzymes. Metabolic disorder like alcaptonuria and phenylketonuria are detected by analysis of enzymes of amniotic fluid.Somatic cells (skin cells) analysis determine the sex of child. While congenital diseases like Down's syndrome, Turner's syndrome are determined by karyotypic study of somatic cell.