Impact, logistics and prospects of traditional prenatal diagnosis

Traditional second trimester prenatal diagnosis (PD) by amniocentesis was introduced about 20 years ago. It is still the most frequently used procedure for this purpose. About 85% of all requests for PD are based on maternal age alone. The commonest indication is a maternal age of 35 or higher at delivery. Attempts are being made to improve utilization of the limited laboratory capacity by evaluating the indication for PD by combining age and other indicators, ie. maternal-serum-alpha-fetoprotein and unconjugated estriol. Chorionic villus sampling so far has appealed to an additional group of pregnant women rather than being a replacement for the older procedure. While the impact of PD on the individual woman and her family is great, it has limited impact on the prevalence of Down syndrome patients in the society. Of major concern is the impact of PD on the attitude to a pregnancy with a possibly affected child, on the attitude to induced abortion in general and on the acceptance of disabled individuals. The importance of proper genetic counseling including ethical issues is stressed.