Down's syndrome in west jerusalem

Down's syndrome has been studied in 42, 340 births to West Jerusalem residents in 1964-1970. The overall rate was 2.4/1000 total births. There were no significant differences, after adjustment for maternal age, between Arabs and Jews, nor between Jewish subgroups of Asian, North African or Western origin, although the risk in Westerners was considerably lower. The age-adjusted risk of Down's syndrome was significantly rare among first births, and in mothers aged under 35 there was a significant effect of standard-of-living, the age-adjusted risk decreasing with increasing paternal education. There were significantly more cases than expected in association with maternal anemia, in religiously observant Jewish women who regularly use the ritual bath, and in mothers of blood group B and AB, while cases were rare in mothers of blood group A.