Abstract
The relation between periconceptional vaginal spermicide use and sex ratio at birth, birthweight, and the frequency of congenital anomalies was examined in a cohort of 2,712 New York City obstetric patients, 149 of whom (5.5 per cent) became pregnant while using spermicides or had used spermicides before and after conception. Periconceptional spermicide use was not associated with any important variation in the expected sex ratio at birth, nor with major or minor congenital anomalies. Exposure to spermicides in the periconceptional period, defined dichotomously as present or absent, was not associated with decreased birthweight in male or female infants. There was a slight decrease in birthweight among female infants with increasing duration of postconceptional spermicide use; an estimated 7.4 grams decrease with each day of use. The size of the effect and its selectivity by sex suggest a chance finding.