Tougher to get pregnant when stressed

A new study in the current issue of the journal Fertility and Sterility lends credence to a link between stress and time to conception, and not just in couples dealing with infertility. The study involved 274 British women 18 to 40 years old in the Oxford Conception Study, which examined whether information from fertility-monitoring devices would improve their chances of conception. They were followed for six menstrual cycles or until they got pregnant, whichever came first. On Day 6 of each cycle, they collected saliva samples. Researchers measured their levels of alpha amylase and cortisol, two substances that serve as barometers of how the body reacts to physical or psychological stress. After accounting for couples' ages, intercourse frequency and alcohol intake — all factors that could influence pregnancy chances — the scientists found that women with highest concentrations of alpha amylase in the first cycle were 12% less likely to conceive than women with the lowest. On average, couples have a 30% chance of conceiving each cycle. (Few of the women smoked, the lifestyle factor most strongly linked to time to conception.) Cortisol levels were not associated with the women's chances of conceiving.