Perceived stress, reproductive hormones, and ovulatory function: a prospective cohort study.

Background: Stress has been shown to suppress ovulation in experimental models, but its effect on human reproduction at the population level is unclear.
Methods: Healthy women (n = 259), aged 18-44 years from Western New York, were followed for 2 menstrual cycles (2005-2007). Women completed daily perceived stress assessments, a 4-item Perceived Stress Scale (PSS-4) up to 4 times each cycle, and a 14-item PSS at baseline. Mixed model analyses were used to assess effects of stress on log reproductive hormone concentrations and sporadic anovulation.
Results: High versus low daily stress was associated with lower estradiol (-9.5% [95% confidence interval (CI) = -15.6% to -3.0%]), free estradiol (-10.4% [-16.5% to -3.9%]), and luteinizing hormone (-14.8% [-21.3% to -7.7%]) and higher follicle-stimulating hormone (6.2% [95% CI = 2.0% to 10.5%]) after adjusting for age, race, percent body fat, depression score, and time-varying hormones and vigorous exercise. High versus low daily stress was also associated with lower luteal progesterone (-10.4% [95% CI = -19.7% to -0.10%]) and higher odds of anovulation (adjusted odds ratio = 2.2 [95% CI = 1.0 to 4.7]). For each unit increase in daily stress level, women had a 70% higher odds of an anovulatory episode (odds ratio = 1.7 [1.1 to 2.4]). Similar but attenuated results were found for the association between the PSS-4 and reproductive hormones, while null findings were found for the baseline PSS.
Conclusion: Daily perceived stress does appear to interfere with menstrual cycle function among women with no known reproductive disorders, warranting further research to explore potential population-level impacts and causal biologic mechanisms.