The association between work hours, shift work, and job latitude with fecundability: A preconception cohort study.

The role of occupational stress on male fertility is understudied. We examined associations between male occupational stress and fecundability. We used data from Pregnancy Study Online (PRESTO), a North American preconception cohort study. At baseline (2013-2019), male participants aged ≥ 21 years completed a baseline questionnaire on employment status, hours worked per week, time of day worked (daytime, evening, nights, and changing or rotating shifts), and job title. We used the O*NET occupational database to rate independence by job title. Female partners were followed via bimonthly follow-up questionnaires for 12 months or until pregnancy. We restricted analyses to 1,818 couples attempting conception for ≤ 6 cycles at enrollment. We used proportional probabilities regression to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs). The FR comparing unemployed with employed men was0.84 (95% CI: 0.62-1.14). Among employed men, FRs and 95% CIs for evening shift work, night shift work, and rotating shift work were 0.89 (95% CI: 0.68-1.17), 0.94 (95% CI: 0.66-1.33), and 0.91 (95% CI: 0.75-1.11) relative to daytime shift work. The FR for any nondaytime shift work was 0.91 (95% CI: 0.78-1.07). Total work hours (long or short) and job independence scores were not appreciably associated with fecundability. In conclusion, working nondaytime shifts and being unemployed were associated with slightly decreased fecundability. However, the variability in these estimates was substantial and the results were reasonably consistent with chance. Little association was observed for other occupation measures. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Male sleep duration and fecundability in a North American preconception cohort study.

OBJECTIVE: To evaluate prospectively the association between male sleep duration and fecundability. DESIGN: Pregnancy Online Study (PRESTO), a Web-based prospective cohort study of North American couples enrolled during the preconception period (2013-2017). SETTING: Not applicable. PATIENT(S): Male participants were aged ≥21 years; female participants were aged 21-45 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): At enrollment, men reported their average nightly sleep duration in the previous month. Pregnancy status was updated on female follow-up questionnaires every 8 weeks for up to 12 months or until conception. Analyses were restricted to 1,176 couples who had been attempting to conceive for up to six cycles at enrollment. Proportional probabilities regression models were used to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs), adjusting for potential confounders. RESULT(S): Relative to 8 hours per night of sleep, multivariable-adjusted FRs for <6, 6, 7, and ≥9 hours per night of sleep were 0.62 (95% CI 0.45-0.87), 1.06 (95% CI 0.87-1.30), 0.97 (95% CI 0.81-1.17), and 0.73 (95% CI 0.46-1.15), respectively. The association between short sleep duration (<6 hours per night) and fecundability was similar among men not working nights or rotating shifts (FR 0.60, 95% CI 0.41-0.88) and among men without a history of infertility (FR 0.62, 95% CI 0.44-0.87) and was stronger among fathers (FR 0.46, 95% CI 0.28-0.76). CONCLUSION(S): Short sleep duration in men was associated with reduced fecundability. Because male factor accounts for 50% of couple infertility, identifying modifiable determinants of infertility could provide alternatives to expensive fertility workups and treatments.