http://www.telegraph.co.uk/health/healthnews/5286670/Morning-sickness-increases-the-chance-that-child-will-have-high-IQ.html
The same hormones which make expectant mothers feel ill could help their baby's development, doctors believe.
Children were more likely to do better in intelligence tests if their mothers had experienced nausea and vomiting during pregnancy.
The findings, published online in The Journal of Paediatrics and reported by New Scientist magazine, show that the severity of the sickness is a significant predictor of higher scores.
Dr Irena Nulman, from The Hospital for Sick Children in Toronto, Canada, said: "Our findings suggest an association between morning sickness and improved neurodevelopment in the offspring."
She said that more research was needed to understand the range of effects caused by the common condition.
"Morning sickness is a widespread and puzzling physiological phenomenon that has yet to be sufficiently studied," she said.
Scientists believe that the sickness could be a by-product of changes in the levels of certain hormones, known as HCG (human chronic gonadotropin) and thyroxine, during pregnancy.
These fluctuations help the body to ensure that a woman's placenta grows properly, delivering vital nutrients to her baby.
The study followed 121 women who fell pregnant between 1998 and 2003.
The IQ levels of their children were tested between the ages of three and seven.
Other factors such as mother's IQ, her level of alcohol consumption and socioeconomic status, which can affect a child's IQ, were taken into account during the study.
While previous studies suggested an early protective benefit of morning sickness, the long-term effects, including on intelligence, had not been directly investigated before.
Dr Irena Nulman, of The Hospital for Sick Children in Toronto, Canada, said: "Our findings suggest an association between morning sickness and improved neurodevelopment in the offspring.
"Morning sickness is a widespread and puzzling physiological phenomenon that has yet to be sufficiently studied."
