New evidence of the influence of exogenous and endogenous factors on sperm count in man.

Objective: To examine the association between individual exposures due to occupation, environment and lifestyle on sperm count, we conducted a case-control study among 92 fertile and 73 sub-fertile Caucasian males.

Study Design: Data from questionnaires were analysed using simple univariate and multivariate logistic regression models.

Results: At risk for oligozoospermia are men exposed to pesticides (odds ratio (OR) 8.4; 95% confidence interval (CI) 1.3-52.1), welding (OR 2.8; CI 0.9-8.7), antibiotic use (OR 15.4; CI 1.4-163), a history of mumps (OR 2.9; CI 1.3-6.7), gastrointestinal complaints (OR 6.2; CI 1.4-26.8), decreased intake of fruits (OR 2.3; CI 1.0-5.1), vegetables (OR 1.9; CI 0.7-5.0), or with female fertility disorders in their families (OR 8.4; CI 1.7-41.9). Unlike other studies, no associations were observed between oligozoospermia and exposure to paint or heat.

Conclusion: This study suggests new risk factors oligozoospermia in man and confirms previously reported results from others.