Women who are stressed during pregnancy could increase the chances of their children suffering from anxiety and depression, behavioural problems and learning difficulties, scientists say.
This is not particularly helpful information for worried mothers-to-be. It's just one more thing to worry about!
However researchers from Imperial College London are hoping their study will raise families' awareness of the importance of reducing levels of stress and anxiety in expectant mothers.
They say if pregnant women could relax more it could help prevent thousands of children from developing emotional and behavioural problems.
Their exhibit at the Royal Society Summer Science Exhibition gives people the chance to see how stress levels can affect the heart rate of an unborn baby.
The placenta usually protects the unborn baby from the stress hormone cortisol.
But when the mother is stressed, the placenta becomes less protective and the mother's cortisol may have an effect on the foetus, according to the researchers.
Professor Vivette Glover, lead researcher behind the exhibit from the Institute of Reproductive and Developmental Biology at Imperial College London, says: "We all know that if a mother smokes or drinks a lot of alcohol while pregnant it can affect her foetus.
"Our work has shown that other more subtle factors, such as her emotional state, can also have long-term effects on her child. We hope our exhibit will demonstrate in a fun way why we all need to look after expectant mothers' emotional well-being."
She says stress caused by a bad relationship with the baby's father can be particularly damaging.
"We want fathers visiting our exhibit to see how they can help with the development of their child even before the birth, by helping their partner to stay happy," says Professor Glover.
Now that is good advice. Most expectant fathers do their best to keep their partners happy anyway, of course, but here's an added incentive to put up with the hormonal nightmare as best you can.
Employers should also take note - if anybody can prove that stress at work damaged their baby, lawsuits are surely just around the corner.
Do you know any good ways of reducing stress during pregnancy? I'd like to hear your tips, for next time around...
Source [Imperial College, London]