It is a method by which the baby in the mother's womb can be diagnosed whether it is suffering from thalessemia major or with sickle cell disease. Tissue sampling is done by chronic villi biopsy (8 - 10 weeks) or by amniocentesis (11-14 weeks). As it represents the baby in-utero the analysis of the tissue helps to diagnose the baby. The diagnosis is done by molecular techniques such as PCR, microarry or sequencing method. Prenatal Diagnosis is most sophisticated method in the world and gives appropriate results in 98-99 % cases.
In cases of repeated abortions, both the partners blood is checked for any chromosomal defects by growing their blood cells artificially .
In cases of earlier birth of Down syndrome (genetic condition with mental retardation) baby, further birth of similar baby can be prevented by analyzing the chromosomes of the earlier baby and their parents and if required of baby inside the uterus and decide a strategy.