A Case-Control Study of Maternal Occupation and the Risk of Orofacial Clefts

Objectives: The aim of this study was to examine the association between maternal occupation and risk of orofacial clefts in offspring. Methods: Data were obtained from the Texas Birth Defects Registry and vital records for 1999 to 2009 deliveries. We used automated software to assist in classifying occupations into standard codes. Using multivariable logistic regression, the risk for cleft lip with or without cleft palate (CLP) or cleft palate only (CP) in offspring was compared between women in each of 20 major occupation groups to women in every other occupation group. Results: Significant positive associations were observed between business/finance and architecture/engineering occupations and CP and between cleaning-related occupations and CLP. A significant negative association was observed between office and administrative support occupations and CLP. Conclusions: This study supports previous reports of increased risk of orofacial clefts in offspring among women in certain occupations.