SEASON OF BIRTH AND BIRTH ORDER IN RELATION TO PRENATAL PATHOLOGY

Abstract

Janerich, D. T. and J. Garflnkel (Birth Defects Institute, New York State Dept. of Health, Albany, N. Y. 12208). Season of birth and birth order in relation to prenatal pathology. Amer. J. Epid., 1970, 92: 351–356.—New York birth records for a 9-year period were used to determine the rate of late fetal death and congenially malformed live births in relation to season of birth and birth order. The rate of prenatal pathology was highest among births occurring in January-February and in June. Moreover, the seasonal distribution of births was found to vary between birth orders. Within specific birth order groups these seasonal peaks in prenatal pathology were found to coincide with a decreased frequency in births. This inverse relationship between the occurrence of congenital disease and births, suggests that the factors responsible for the increased rate of congenital disease may also effect the distribution of births. The lack of similarity in the pattern of inverse relationship between birth order groupings is suggestive of different causes for the high incidence of congenital disease between January–February births and June births.