Science is telling women to “chill out” if they want to get pregnant. Research published in early 2017 showed that women with the hormone Cortisol, more commonly known as the stress hormone, present in their hair were 1/3rd less likely to become pregnant than women who did not have the hormone present in their hair.
Hair was tested because it provides a more in-depth picture of long term hormone implications. Hair follicles provide information dating back 3-6 months, whereas blood and saliva samples offer only a snapshot of current hormone levels.
The study, conducted by Nottingham University and published in Psychoneuroendocrinology, followed more than one hundred women over a period of 18 months and tracked their salvia cortisol levels as well.
While saliva levels were not found to have any impact on likelihood of achieving pregnancy through IVF treatments, the researchers found that participants were 27% less likely to achieve pregnancy when the cortisol was present in the hair shaft. This number accounted for other control groups of things that we already know can impact fertility negatively. Those things include an elevated BMI, number of eggs retrieved, and number of eggs fertilized.
“Researchers have been interested in the role that cortisol may play in determining reproductive outcomes for some time now,” said Professor Kavita Vedhara from the University’s School of Medicine, “There has been ongoing debate within the scientific community about whether or not stress may influence fertility and pregnancy outcomes. 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.”
It is important to note that the presence of cortisol can be related to many things other than just a stressful lifestyle. Things like poor diet, lack of exercise, and overindulgence in caffeine have also been linked to an elevated level of cortisol. The study did not evaluate if any of these factors may have been responsible for the elevated cortisol levels.
Researchers say the plan is to continue research into the link between cortisol, namely as a result of stress, and its link to fertility in the coming years. In the meantime, they’re asking women undergoing IVF treatments to try and relax, as it seems highly likely that it may help their odds at conception.