Why are some women not getting pregnant? According to Today, it could be stress. Many times when a woman is trying to start a family she's told, "Relax, and it will happen."

According to a new study this might be more literal than we thought. Women who had a high level of a stress biomarker in their saliva took 29 percent longer to get pregnant than women with a low level. Furthermore those with a higher level of stress were twice as likely to meet the clinical definition for infertility.

The author of the study, Courtney Lynch, director of reproductive epidemiology at The Ohio State's Wexner Medical Center, points out how many women will get pregnant while on vacation or how many women who were declared infertile and adopted become pregnant soon after the adoption. Could it be that once finally relaxed the body does its thing? Maybe. In the big fertility picture however, Lynch says stress “is a minor issue,” compared to other factors that can affect it, such as blocked tubes, ovarian problems, smoking or age.