Objectives This study investigated the possibility of men`s work in greenhouses and their exposure to pesticides being associated with reduced fertility.

Methods A study on time to pregnancy was conducted among the families of Finnish male greenhouse employers and employees. Exposure to pesticides was assessed on the basis of questionnaire information and data gathered from the enterprises. Fecundability density ratios (FDR) for occupational exposure were calculated with discrete proportional hazards regression analyses.

Results After three mailings, 578 (43%) couples participated. Fecundability was suggestively decreased for exposed greenhouse workers who were inefficiently protected, with FDR values of 0.67 [95% confidence interval (95% CI) 0.33-1.35], 0.92 [95% CI 0.45-1.88] and 0.77 [95% CI 0.46-1.29] for high exposure, moderate exposure and low exposure, respectively, as compared with unexposed greenhouse workers. The exposed men who efficiently used personal protective equipment were as fertile as the unexposed greenhouse workers. Exposure to pyrethroids (FDR 0.40, 95% CI 0.19-0.85) was related to decreased fecundability. Suggestive associations were observed for organophosphates (FDR 0.70, 95% CI 0.42-1.17) and carbamates (FDR 0.55, 95% CI 0.27-1.11).

Conclusions The findings of the study provide limited support for the hypothesis that exposure to pesticides is associated with reduced fertility. The findings for pyrethroids, organophosphates, and carbamates can serve as a basis for a hypothesis for future studies.

Key terms exposure; fecundability; Finland; greenhouse worker; male; pregnancy delay; reproductive health; time to pregnancy; wife