Sniffles and sneezes during pregnancy could increase a mother's chances of her child having asthma, US research has shown.
Scientists who studied 513 pregnant women and their 526 children found an association between viral infections suffered by pregnant mothers and childhood asthma risk.
The more colds and other infections a woman had, the more likely she was to give birth to a baby that developed asthma.
Infections during pregnancy can alter the womb environment and affect a child's developing immune system, experts believe.
The findings are published in the journal Annals of Allergy, Asthma and Immunology.
Children in the study were assessed at three and 12 months, and then every year until they were five.
Of the families studied, 61 per cent had a parent with asthma, hay fever or eczema.
Dr Michael Foggs, president of the American College of Allergy, Asthma and Immonology, which publishes the journal, said it was already known that allergy and asthma can develop in the womb, since genetics play a factor in both diseases.
"But this study sheds light about how a mother's environment during pregnancy can begin affecting the child before birth."