Women who suffer from morning sickness during pregnancy are up to 50 per cent less likely to have a miscarriage, according to researchers.
Scientists think the loss of appetite and avoidance of certain foods have a surprise benefit of helping protect the unborn child.
It is estimated that anywhere from 50 to 80 per cent of expectant mothers experience morning sickness, and it typically occurs during the first three months. For some, it is so severe they cannot keep anything down and need to be admitted to hospital to be put on a drip.
Now scientists working for the US government's health department have found that the debilitating condition may help protect the foetus.
In a study published in the journal JAMA Internal Medicine, they looked at 797 women who gave birth or had a miscarriage between 2007 and 2011. Those who experienced morning sickness during the first three months were on average 50 per cent less likely to lose the baby.
The researchers said the woman's reduced calorie intake encouraged the placenta - which provides the foetus with nutrients - to grow. And by eating fewer foods, the woman would be less likely to expose the baby to harmful toxins.
Janine Elson, of the Royal College of Obstetricians and Gynaecologists said: "This should provide some reassurance for women suffering from nausea. However, it is important to emphasise that if a woman isn't suffering from nausea and vomiting, it doesn't mean she will miscarry."