The American Journal of Epidemiology published the finding from the Pregnancy Study Online (PRESTO), an ongoing preconception cohort of North American pregnancy planners that follows couples for 12 months or until pregnancy, whichever comes first. The researchers followed 4,769 women and 1,272 men who did not have a history of infertility and had not been trying to conceive for more than six menstrual cycles.
The items referred to the past month, with five response choices ranging from 0 (never) to 4 (very often), up to a total of 40, with a higher total score indicating a higher level of perceived stress. Both partners completed the PSS (Perceived Stress Scale) at baseline, and women also completed the PSS at each bi-monthly PRESTO follow-up.
The researchers found women with PSS scores of at least 25 were 13 percent less likely to conceive than women with PSS scores under 10. The association was also stronger among women under 35 years old.
The researchers did not find an association between men’s PSS score and the likelihood of conceiving. However, couples in the study were about 25 per cent less likely to conceive when the man’s PSS score was under 10 and the women’s was 20 or higher.