Morning sickness afflicts most pregnant women, but new research has found it comes with a silver lining.
Women who suffer nausea and vomiting - that's 80 percent of mothers-to-be - have a 50 to 75 percent reduced chance of losing their baby, even if they've had a previous miscarriage, researchers at the US National Institutes of Health have found.
The study looked at 797 pregnant women, tracking their morning sickness and their pregnancies to term.
By week eight, 83.9 percent of the women had reported nausea, 26.6 percent with vomiting too.
At the end of the observation, the researchers found nausea led to a 50 percent drop in miscarriages, and nausea with vomiting, a 75 percent drop.
"Our study confirms prior research that nausea and vomiting appear to be more than a sign of still being pregnant and instead may be associated with a lower risk for pregnancy loss," the study concluded.
Two years ago Canadian researchers found a similar link between nausea and healthy, full-term babies. That study also found a link between morning sickness and IQ scores.
It was proposed that increased hormone levels are behind the favourable outcomes, but this remains unproven.
Further research is needed, the researchers behind the latest study say.
The findings are published online today by JAMA Internal Medicine.