Antenatal diagnosis--its present status and future prospects.

In the past decade dramatic developments have taken place in antenatal diagnosis. Various techniques are now fully established as routine procedures and these are applicable to several categories of genetic diseases. Transabdominal amniocentesis is currently the most important method for the prenatal diagnosis of chromosomal conditions, neural tube defects and biochemical disorders. Ultrasonography is playing an increasingly important role in the detection of malformations, while fetoscopy is now employed for fetal blood sampling, biopsy and visualization. Recombinant DNA techniques hold great promise for the intra-uterine diagnosis of common and important disorders in which the fundamental defect is unknown.