Purpose: Occupational factors have been associated with risk of orofacial clefts in offspring, although data are limited. We explored associations between parent's occupation and isolated orofacial clefts using a population-based case-control study. Methods: Cases were restricted to infants born with an isolated orofacial cleft in Norway during the period 1996 to 2001 (314 with cleft lip with or without palate [CLP] and 118 with cleft palate only [CPO]). Controls (n = 763) were chosen randomly from all Norwegian live births. We considered full-time employment during the first 3 months of pregnancy. Results: Several maternal occupations previously associated with clefts showed some evidence of association, including hairdressers (CLP; adjusted odds ratio = 4.8; 95% confidence interval [CI]: 0.99-23). Mothers working in manufacturing and in food production had increased odds for babies with CPO (3.8; 1.3-11, and 7.1; 1.5-33, respectively). Among fathers' occupations previously associated with clefts, an association was suggested for woodworking both for CLP (1.7; 0.85-3.2) and for CPO (2.0; 0.82-4.7). Fathers working as professional housekeepers showed substantial increased odds of CPO (12; 3.3-46). Conclusions: Taken together with previous studies, these results suggest that exposures in certain occupations may influence the risk of orofacial clefting in offspring. Specific exposures accompanying these occupations warrant exploration.
Bibliographical noteFunding Information:
This project was supported in part by the Intramural Research Program of the National Institutes of Health (NIH), National Institute of Environmental Health Sciences (NIEHS). The authors are grateful for helpful suggestions by Drs. Olga Basso and Christine Parks on an earlier draft. The authors acknowledge the dedication of the Norwegian study staff, including Nina Høvland, Åase Gunn Mjaatvedt, and Maria Teresa Acuero, and that of the participating families.
- Cleft Lip
- Cleft Palate