When it comes to your likelihood of conceiving using IVF, the answers may be found right on top of your head.
That's right—it might sound kind of strange, but according to a small new study, the levels of a stress hormone known as cortisol found in your hair can predict the odds of pregnancy when undergoing in vitro. In fact, researchers at The University of Nottingham have found that elevated levels of cortisol were associated with almost a third less chance of conceiving!
Interesting stuff, especially if you're a woman who's currently trying to conceive. But why use hair? Because doctors can measure cumulative hormonal function over a period of three to six months using your locks, as opposed to other techniques—saliva, blood, or urine, for example—which only measure short-term levels.
For the study, the researchers collected salivary cortisol samples from 135 women, 60 percent of whom later became pregnant following IVF treatment. Hair samples were also taken from 88 of the women. And after analyzing both, the researchers found that while the salivary cortisol measurements were not related to the chance of getting pregnant, 27 percent of the variance in pregnancy outcome could be attributed to the hair cortisol concentrations.
Pretty cool, right? And according to the researchers, these findings provide the first concrete evidence that long-term levels of cortisol—affected by things like diet, exercise, and, yes, stress—may play an important role in determining reproductive outcomes.
"There has been ongoing debate within the scientific community about whether or not stress may influence fertility and pregnancy outcomes," explained Professor Kavita Vedhara from the University's School of Medicine, who led the study. "While these results do not specifically implicate stress they do provide preliminary evidence that long-term cortisol levels are associated with a reduced likelihood of conceiving."
Which is why Dr. Adam Massey, also from the University's School of Medicine, acknowleges that while we still do not fully understand all of the factors that influence whether or not treatment works, reducing cortisol in the months prior to treatment remains paramount.
"The good news for patients," he explained, "is that well known lifestyle changes may help to lower cortisol and therefore optimize the likelihood they will get pregnant."