Adverse birth outcomes associated with selected maternal occupations in 12 European birth cohorts – a CHICOS initiative

Background:Occupational maternal exposures during pregnancy may affect fetal development. The population-based birth cohort design has been used very few times in this field; however, they collect data prospectively and self-reported by the mother, and can follow children up for many years. Aims: To examine the association between selected maternal occupations and adverse birth outcomes and evaluate the heterogeneity between cohorts. Methods: As part of the CHICOS project (www.chicosproject.eu), a total of 12 European birth cohorts studying more than 200,000 mother-child pairs were included. Nine occupational sectors were defined as being exposed to a range of specific environmental agents: health, day-care, cleaning, agriculture, electricity, laboratory work, food industry, printing and painting, and hairdressers. The reference group was defined as being non-exposed to environmental agents including managers, computer workers, and office clerks. Adverse birth outcomes assessed were: birth weight, small-f...