Article Text
Abstract
Objectives Previous studies indicate that sons of women working with pesticides may have an increased risk of cryptorchidism. This study assessed the risk of cryptorchidism among boys of parents employed as farmers or horticultural workers using nationwide registers on parental occupation and cryptorchidism diagnoses.
Methods Our study cohort of more than 600,000 boys included all boys born in Denmark from 1980 to 2007 with a mother or father in employment during pregnancy. The cohort was followed for the occurrence of cryptorchidism and orchiopexy from 1980 to 2009 comparing the risk in sons of horticultural workers and farmers with sons of parents in other occupations. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression adjusting for maternal and paternal age, birth years and parity.
Results Maternal employment as farmer was associated with moderately increased risks of cryptorchidism (cases 157; HR 1.31; 95% CI 1.12–1.53) and orchiopexy (cases 111; HR 1.29; 95% CI 1.07–1.56) compared to children of mothers in other occupations (15511 cases of cryptorchidism and 9963 of orchiopexy). Paternal occupation as farmer was unrelated to the risk in sons. Maternal occupation as horticultural worker was associated with non-significantly increased risks of cryptorchidism (cases 72; HR 1.20; 95% CI 0.95–1.52) and orchiopexy (cases 51; HR 1.28; 0.97–1.68). Similar associations were found for paternal horticultural workers. Prior but not current maternal employment as horticultural worker or farmer was not associated with an increased risk.
Conclusions This register-based study provides support for a possible association between maternal employment as a farmer during pregnancy and cryptorchidism in boys. Our finding of similarly increased risks in sons of mothers and fathers employed as horticultural workers question whether this association is causally related to pesticide exposure or has alternative explanations.