Objectives The association between fertility and job strain defined as high job demands and low job control has not previously been studied. A follow-up study was conducted with prospective collection of information on job strain among women, achievement of pregnancy, and potential confounding variables.

Methods A total of 297 Danish couples without previous reproductive experience was followed for a maximum of 6 menstrual cycles from termination of birth control until pregnancy. Job demand and job control were measured by a questionnaire developed by Karasek and his co-workers.

Results The odds ratio and 95% confidence interval (95% CI) for conception per menstrual cycle for women with high job strain was 0.9 (95% CI 0.5-1.5) when compared with that of women in low-strain jobs. Only in secondary analyses restricted to couples with no suspected competitive causes of reduced fertility was a statistically significant reduced odds found for women with high-strain jobs compared with all other jobs.

Conclusion The main finding of this study did not corroborate a hypothesis of a substantial detrimental effect of job strain on fecundability.

Key terms fecundability; fertility; occupation; prospective data; reproduction; stress