Congenital malformations related to maternal exposure to specific agents in biomedical research laboratories

Objective: To investigate major congenital and neural crest malformations (NCM; craniofacial and conotruncal defects) in the offspring of laboratory employees. Methods: Data for 1951 females was linked to the Medical Birth Register (3003 pregnancies). Exposure information was based on questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: The prevalence of "major malformations" were 2.3% (n = 41; exposed) and 1.9% (n = 23; unexposed). For the major malformations, solvent exposure before the third trimester gave an OR of 1.8 (CI = 1.0-2.9); "laboratory work in general," of 1.2 (CI = 0.7-2.0) unadjusted. OR for benzene use around conception/organogenesis was 5.3 (CI = 1.4-21.1) for NCM. Conclusion: No significant risk for laboratory work in general was seen, but there was an increased ratio for NCM relative to solvents, especially benzene. These results are based on small numbers and should be interpreted cautiously.