Drinking water disinfection byproducts and risk of orofacial clefts in the National Birth Defects Prevention Study

Background Maternal exposure to drinking water disinfection byproducts (DBP)s may contribute to orofacial cleft (OFC) development, but studies are sparse and beset with limitations. Methods Population‐based, maternal interview reports of drinking water filtration and consumption for 680 OFC cases (535 isolated) and 1826 controls were linked with DBP concentration data using maternal residential addresses and public water system monitoring data. Maternal individual‐level exposures to trihalomethanes (THM)s and haloacetic acids (HAA)s (µg/L of water consumed) were estimated from reported consumption at home, work, and school. Compared to no exposure, associations with multisource maternal exposure