Spina bifida and parental occupation

To examine the association between parental occupation and spina bifida in offspring, we conducted a multicenter case-referent study in the Netherlands. Cases were children with spina bifida aperta from nine different hospitals throughout the country; the referent group comprised population based referents who were randomly drawn from municipal birth registries. All children were born between 1980 and 1992. We collected data using postal questionnaires for both parents with questions about occupational title, industry, daily occupational activities, and a number of potential confounders. We were able to include 353 cases and 1,329 referents in the analyses. We found increased risks for maternal agricultural occupations [odds ratio (OR) = 5.6; 95% confidence interval (CI) 1.8-17.8] and for cleaning women (OR = 1.9; 95% CI = 0.9-3.9). For the fathers, we saw increased odds ratios for welders (OR = 2.1; 95% CI = 0.6-7.0) and transport workers (OR = 1.4; 95% CI = 0.9-2.1).