Anencephalus in Japan 1969-1978 : Geographical Variations

Abstract

Nation-wide data in Japan on pre- and post-natal deaths of 9,641 individuals with anencephaly during 1969-1978 were analysed. Mean overall incidence of anencephaly per 1,000 births was 0.474. The incidence was the highest in ward and followed by gun and city. The incidence was higher in the northeast than the southwest of Japan. Incidence of anencephaly increased with the year in ward, city, gun and six districts.