Scientists at The University of Nottingham have found new evidence that hormone levels measured in hair can affect the IVF success rate by 27%.
The new study, funded by Nurture Fertility, found that elevated levels of the so-called ‘stress hormone’ cortisol measured in hair were associated with almost a third less chance of conceiving.
Only around 35% of couples who go through fertility treatment end up becoming parents.
Between December 2012 and April 2015, a total of 135 women were recruited from NURTURE fertility clinic in Nottingham. 60% of these women became pregnant following IVF treatment.
Salivary cortisol samples were collected over two days. 88 of the women also provided hair samples for the measurement of cortisol.
After analysing both types of cortisol data researchers found that short term salivary cortisol measurements were not related to pregnancy but in contrast the hair cortisol concentrations were.
Researchers found that some women with higher levels of cortisol didn't get pregnant using IVF.
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. > A range of factors are likely to account for that, stress being one possibility. These findings are clearly compelling but more research is needed to more fully understand the factors that influence cortisol levels in patients undergoing IVF”.
The findings provide the first proper evidence that long term levels of cortisol, which are affected by many lifestyle factors including diet, exercise, caffeine and most notably stress, may play an important role in determining reproductive outcomes.
Scientists believe that interventions to reduce cortisol prior to infertility treatment could therefore improve outcomes for the many thousands of couples undergoing IVF each year.
Tips for women trying to get pregnant:
have an average to normal weight
take moderate, but not excessive exercise
have a good and balanced diet
IVF consultant, Dr Gillian Lockwood says for men wearing tight trousers, long distance driving and sitting with a laptop on your lap is bad for sperm.