There is now scientific evidence to
back up the widely held belief that stress can interfere with fertility.
Women in a newly published study
were less likely to conceive when they exhibited higher levels of a
stress-related enzyme known as alpha-amylase.
The research is the first of its
kind to suggest a biological basis for the long-held notion that stress can
reduce a woman’s chances of becoming pregnant.
More Stress, Fewer Pregnancies
Researchers from the US National
Institutes of Health and the UK’s University of Oxford followed 274 couples
trying to conceive for six months. None of the women in the study had a history
of infertility, and all tracked their monthly cycles using at-home fertility
On their sixth cycle day each
month, the women provided saliva samples that were tested for alpha-amylase and
another stress hormone, cortisol.
Cortisol levels did not appear to
influence conception during the six days when pregnancy was most likely to
occur. But women with the highest alpha-amylase levels were roughly 12 per cent
less likely to get pregnant during each cycle than women with the lowest
The study was published online in
the journal Fertility and Sterility.
Stress May Slow Egg Passage
Long known as an enzyme that helps
the body digest starch, alpha-amylase has only recently been recognized as an
indicator of stress, says Germane Buck Louis of the Eunice Kennedy Shriver
National Institute of Child Health and Human Development.
Alpha-amylase is secreted when the
nervous system produces compounds known as catecholamines in response to the
“fight or flight” stress reactions.
Ms Buck Louis says there is early
evidence that catecholamines released in response to this type of stress reduce
blood flow, which slows the passage of the fertilized egg to the uterus.
“That may mean the egg does not get
there in time to implant,” she said. “This is all very speculative at this
point, but we are hoping this research will stimulate scientists who study
stress response to explore it more carefully.”
Ms Buck Louis’ research team is in
the final phases of a larger study in which couples trying to conceive were
followed for a full year.
One goal is to determine if failure
to achieve pregnancy affects stress hormone levels and, if so, how this affects
The findings support the idea that
taking steps to reduce stress at work or at home may help fertile women achieve
a desired pregnancy, study researcher Cecilia Pyper of the University of Oxford
While this has not been confirmed
in scientific studies, the anecdotal evidence abounds. It seems that just about
everyone knows someone who conceived on vacation or at some other time when
stress levels were low.
“Relaxing certainly won’t do
couples trying to conceive any harm,” Ms Pyper says.