Amniocentesis includes extraction of amniotic fluid by insertion of the needle through the abdomen into the uterus and amniotic sac during 14-16 week old pregnancy.
Amniotic fluid contains amniotic membrane cells and foetus skin cells which are then cultured to detect any chromosomal anomaly in the foetus by analysing chromosomal aberration/defects and also for disclosing the sex of the foetus. Down syndrome is an autosomal disorder (genetic disorder), caused by an extra copy of chromosome number 21 and therefore, can be detected by amniocentesis. Cleft palate is caused by both genetic and environmental factors and can not always be detected using amniocentesis.