Maternal occupational exposure and congenital malformations.
A case-referent study was conducted to assess the risk of congenital malformations in relation to maternal occupational exposure before and during pregnancy. Three hundred and twenty-five cases of major malformations and 325 normal (at birth) referents identified in 15 maternity hospitals were included in the study. The occupational history obtained from an interview of the mother was blindly reviewed by an industrial hygienist who assessed the presence of chemical exposure and the probability of exposure. The results suggested that mothers of the case children with oral clefts were more often exposed to solvents during pregnancy [odds ratio (OR) 7.9, 90% confidence interval (90% CI) 1.8-44.9] and worked more often as cleaners (four cases, no referents). Digestive anomalies (OR 11.9, 90% CI 2.0-149) and multiple anomalies (OR 4.5, 90% CI 1.4-16.9) were also associated with occupational exposure to solvents at work. These results were not modified when differences in maternal age, area of residence, and socioeconomic status were taken into account.