Stress Reduces Fertility
Although up to 25% of women and 21% of men of reproductive age in the US and Canada report daily psychological stress, few studies have investigated whether there is an association between stress and decreased fertility in the population at large.
In a study recently published in the American Journal of Epidemiology by Amelia Wesselink and colleagues at Boston University School of Public Health (BUSPH), higher levels of stress were indeed associated with lower likelihood of conception for women, but not for men. The study did not show a definite cause and effect relationship, but a strong association
The study included women (4,769) and men (1,272) who did not have a history of infertility and had not been trying to conceive for more than six menstrual cycles.
The researchers measured perceived stress using the 10-item version of the perceived stress scale (PSS), a survey designed to assess how uncontrollable, unpredictable, and overwhelming an individual finds her or his life circumstances. The items referred to the previous month, with five response choices ranging from 0 (never) to 4 (very often), up to a total of 40, with a higher total score indicative of a higher level of perceived stress. The PSS was completed by both partners at baseline, and women also completed the PSS every two weeks at follow-up visits. (The baseline questionnaires also included demographic and behavioral factors, including but not limited to ethnicity, household income, diet, sleep, and frequency of sexual intercourse.)
In general, baseline PSS scores were approximately 1 point higher among women than men, with the average follow-up PSS scores among women remaining fairly constant over the 12 months of the study. Women with PSS scores of at least 25 were 13 percent less likely to conceive than women with PSS scores under 10. This association was stronger among women who had been trying to conceive for no more than two menstrual cycles than among women who had been trying for three or more cycles prior to participating in the study. The association was also stronger among younger women (under 35 years old).
The authors suggested that, if, in fact there is a causal relationship between higher levels of stress and lower pregnancy rates, it may be due in part to decreased intercourse frequency and increased menstrual cycle irregularity.
No association was noted between men's PSS scores and the likelihood of conceiving. Interestingly, however, couples in the study were about 25 percent less likely to conceive when the man's PSS score was under 10 and the women's was 20 or higher. “Stress discordancy” between partners resulted in fewer pregnancies!
- A K Wesselink, E E Hatch, K J Rothman, J L Weuve, Aschengrau, R J Song, L A Wise. Perceived Stress and Fecundability: A Preconception Cohort Study of North American Couples. American Journal of Epidemiology, 2018; DOI: 10.1093/aje/kwy186