Prenatal testing for Down syndrome in the Jewish and non-Jewish populations in Israel.

The present work evaluated the efficacy of a prenatal diagnosis program in which amniocentesis and chorionic villus sampling were offered free of charge to all pregnant women in Israel aged > or = 37 years. The number of Down syndrome (DS) live births that occurred during the period of the program (1978-92) was correlated to the prevalence of old maternal age (> 35 years) and the utilization of prenatal test in the Jewish and non-Jewish populations in 1990 and 1992. It was noted that in the Jewish population, there was a slight increase in the DS live birth rate, from 1.05 in 1978, to 1.37 DS cases/1,000 live births in 1987, which corresponded to an increase in the prevalence of older pregnant women, from 8.0% in 1978 to 14.8% in 1987. Thereafter, however, there was a continuous decline, to 0.71 DS cases/1,000 live births in 1992, as a result of increased acceptance of prenatal testing by women > or = 37 years (67%) and, recently, also by younger women (from 5.6% in 1990 to 14% in 1992). In the non-Jewish population, there has been a very low acceptance rate of prenatal testing (23.3-16.1% in women > or = 37 years and 0.36-0.63% in women < 37 years). As a result, a very low prenatal detection rate (8-16% of all DS cases) and a high prevalence of DS live births (1.4 cases/1,000 live births) were observed. We suggest that a unique genetic counseling approach is required in the non-Jewish population to improve prenatal DS prevention in Israel.