Prenatal screening for genetic disorders

Prenatal testing is the best strategy for reducing the burden of genetic disorders and congenital disabilities that cause significant postnatal functional impairment. Universal prenatal screening is advisable for common genetic disorders and congenital anomalies such as Down syndrome, beta-thalassaemia and neural tube defects. Several prenatal-screening tests are now available for Down syndrome, but knowledge about the appropriate timing of the test and the need for pre- and post-test counselling may not be updated among the primary care physicians. There is also a considerable degree of confusion regarding the prenatal screening test to be chosen in each case, due to the availability of a number of new and advanced screening techniques. At present, there is no nation-wide consensus regarding the nature and timing of these prenatal-screening protocols. Due to the absence of any definite guidelines and the additional lacunae in the awareness regarding the appropriate prenatal screening in the country, the optimum benefits of these screening protocols are not reaching the population. This review focuses on the various prenatal screening and diagnostic tests that are available for common genetic conditions and congenital disabilities and attempts to outline the most cost-effective and gestational age-appropriate strategies for prenatal screening for the Indian healthcare set-up. The recommendations suggested would serve as a source guide for formulating prenatal-screening guidelines for reducing the incidence of common genetic disorders and congenital disabilities in India.