Men whose mothers experience stressful events in the early stages of pregnancy are more likely to face fertility problems, a new study has found.
The study, published in the medical journal Human Reproduction, surveyed 2,804 woman during various stages of their pregnancies between May 1989 and November 1991, and revisited their sons years later when they reached the age of 20.
They found that 63 per cent of men whose mothers had reported at least one stressful life event during the early stages of their pregnancy had lower testosterone levels and sperm counts than those whose mothers did not experience any early pregnancy stress.
Of the 1,454 boys born to the women originally surveyed, 643 of them underwent the second part of the study after reaching 20, which included a testicular ultrasound examination and providing semen and blood samples.
The data also found that men who had been exposed to three or more stressful life events in early gestation had on average a 36 per cent reduction in sperm count. However, exposure to stress in later gestation – after 34 weeks – had less or no affect.
The study catagorised stressful life events to include the death of a close relative or friend, separation, divorce or marital problems, and problems with children.
“This suggests that maternal exposure to stressful life events during early pregnancy, a vulnerable period for the development of male reproductive organs, may have important life-long adverse effects on men’s fertility,” says Roger Hart, senior author of the study and Professor of Reproductive Medicine at the University of Western Australia. “This contrasts with the absence of any significant effect of exposure to maternal stressful life events in late gestation.”
The study took into account many other factors likely to have an impact on fertility including weight, alcohol consumption and whether or not the participant smoked, with Hart noting that stressful events during pregnancy were unlikely to be the sole cause of problems.
“Our findings suggest that improved support for women, both before and during pregnancy, but particularly during the first trimester, may improve the reproductive health of their male offspring," said Professor Hart. “Men should also be made aware that their general health is also related to testicular health, so they should try to be as healthy as possible to ensure that not only do they have the best chance of maintaining fertility, but also of remaining healthy in later life.”