Endocrine Disruptors: Risk Factors For Undescended Testes?
PURPOSE Undescended Testes (UDT) is the most common birth defect in boys with a largely unknown etiology. The authors conducted a case-referent study on risk factors for UDT, focusing on maternal and paternal exposures to endocrine disruptors, in particular. MATERIAL AND METHODS Cases and referents were 203 boys with surgically corrected UDT and 629 boys with middle ear infection, who were recruited at 5 hospitals in the Eastern part of the Netherlands. Referents were frequency matched with the cases on regional postal codes to obtain similar geographical distributions. Both parents of cases and referents filled out postal questionnaires. Confounder adjusted odds ratios (OR) with 95 percent confidence intervals (CI) were estimated using unconditional logistic regression. RESULTS Corresponding with the literature, UDT was associated with low birth weight: OR 2.2 (95%CI 1.1-4.2), multiple gestation: OR 2.2 (95%CI 0.9-5.3), and familial occurrence of the disorder: OR 3.2 (95%CI 2.0-5.1). Use of oral contraceptives after conception also seemed to increase the risk of UDT: OR 3.6 (95%CI 1.0-12.5). Indications were found for associations with gestational preeclampsia, prescriptive drug use, and personal or occupational use of cosmetics immediately prior to or during the index pregnancy for both parents. Additionally, mothers of cases more often reported occupational exposure to dust of divers origins: OR 5.1 (1.6-16.4). CONCLUSIONS The findings reflect a number of risk factors for UDT in general, but provide only some support for a role of endocrine disruptors in its etiology. However, the associations with occupational exposures need a re-evaluation using more valid exposure assessment methods, which is currently being done.