Antenatal exposure to the phenothiazines in relation to congenital malformations, perinatal mortality rate, birth weight, and intelligence quotient score.

In a prospective cohort study of 50,282 gravidas and their offspring, over-all rates of congenital malformations were similar in 1,309 children of women exposed to phenothiazine drugs during the first four lunar months of pregnancy and in 48,973 children of women who were not exposed. There was a suspicion of association between phenothiazine exposure and cardiovascular malformations. In a cohort reduced to 41,337 mother-child pairs for technical reasons, perinatal mortality rates and mean birth weight were similar according to phenothiazine exposure or nonexposure, as were intelligence quotient scores measured at four years of age in 28,358 of the children. Control of potential confounding factors with a variety of multivariate techniques did not materially alter the findings.