According to a new study, psychological stress may indeed make it more difficult to get pregnant.
To understand the link, researchers studied 501 couples for up to 12 months as they tried to conceive, as well as through pregnancy, if it occurred.
The female partners collected their saliva twice to be measured for cortisol and alpha-amylase - two biomarkers that indicate stress levels.
They found that out of 80 percent of women who completed the study, 87 percent became pregnant within the year and 13 percent did not.
Adjusting for factors that can affect fertility, they found that women with highest levels of alpha-amylase had a 29 percent decrease in fertility and were more than twice as likely to be infertile.
“This is the first such effort to demonstrate a link between salivary stress biomarkers and infertility,” researchers noted in a study published in the journal Human Reproduction.