A Study of Temporal Variations in the Risk of Fetal Malformation and Death

Abstract

Data from birth and fetal death registrations in New York City since the war were studied with the object of identifying any short periods in which the risks of malformation or death were high or low, relative to their trend values. The range of fluctuations in these risks was rather narrow, though the absolute numbers of deaths involved may be considerable. Previable age groups exhibited a seasonal minimum of mortality in December with relatively high rates in the late winter and spring. No trace could be found of any excess of deaths or malformations attributable to the Asian influenza epidemic of 1957. A patterned time-distribution was suggested for certain types of malformation.