* Recall past findings associating sperm parameters with occupational exposure to chemicals or work-related psychological distress
* Understand in what occupational, health, and demographic respects workers with male factor infertility differ from those seen for female infertility.
* Note which if any aspects of occupational stress were associated with male infertility in this study.
* Identify any clinical implications of these findings.
The purpose of this work was to investigate the influence of working conditions, occupational exposures to potential reproductive toxic agents, and psychological stress on male fertility. The study population consisted of 202 consecutive male patients attending a fertility clinic. Of those, 106 patients had attended the clinic because of a male infertility problem (case group), 66 patients had attended the clinic because of a female infertility problem (control group), and 30 patients had a combined infertility problem (male and female). Male infertility was associated with working in industry and construction as compared with other occupations (78.6% vs 58.3%, P = 0.044). Industry and construction workers were of lower educational level than the other workers (mean: 12.1 vs 13.4 years, P = 0.021). These patients also tended to smoke more than the other workers (OR = 2.53, 95% CI = 1.08 to 5.98), more often worked in shifts (OR = 3.12, 95% CI = 1.19 to 8.13), reported physical exertion in work (OR = 3.35, 95% CI = 1.44 to 7.80), and were more exposed to noise and welding (OR = 3.84, 95% CI = 1.63 to 9.14, OR = 4.40, 95% CI = 1.11 to 1.76, respectively). Male infertility (case group) was found to be statistically related to higher marks in all four measures of burnout as compared with the controls. The largest difference was obtained in the measure of cognitive weariness (mean:2.9vs 2.1, P < 0.001). In a multiple logistic regression analysis, industry and construction jobs (adjusted OR = 2.2, 95% CI 1.2 to 2.7) and cognitive weariness (adjusted OR = 1.8, 95% CI = 1.03 to 4.6) were found to be independent risk factors for male infertility problems. Male infertility was independently associated with industry and construction jobs as well as job burnout.