Occupational risks for male fertility: an analysis of patients attending a tertiary referral centre

Abstract

The impact of environment and occupation on male fertility is still under debate. We investigated whether certain occupations may be over- or under-represented among men attending our infertility clinic in relation to the entire population of the area. Diagnoses and semen parameters of 2054 infertile men from the district of Münster were analysed retrospectively. The patients were categorized into 29 occupational groups. The relative size of each group was compared with that of the entire population in the district of Münster. Farmers were over-represented compared with the general population. Farmers and painters/varnishers showed a significantly higher proportion of reduced sperm counts [odds ratios (OR): 2.13 and 2.17, 95% confidence intervals: 1.18-3.88 and 1.02-4.65] and severely reduced sperm concentrations compared with the entire group of infertile men; in addition, significantly more farmers presented with a history of maldescended testes than other occupational groups (OR: 2.76 and 2.84; CI: 1.12-6.75 and 1.27-6.34). Metal workers/welders formed significantly higher proportions of patients with reduced sperm motility (OR: 5.99; CI: 1.38-26.00). The relatively poor semen parameters of the painters/varnishers could be caused by exposure to toxins. This may also apply to the farmers (fertilizers, herbicides); however, the elevated rate of maldescended testes suggests an effect of exposure during prenatal development or a genetic cause. The findings for metal workers/welders may be because of heat or toxins at the workplace. The study demonstrates that certain occupations are preferentially associated with male infertility.