Scientists May Have Discovered the Cause of Morning Sickness – and Found a Way to Prevent It

When the joy of pregnancy turns into the misery of morning sickness, the big question for many women is why. British researchers may have finally solved the mystery and figured out a way to prevent the pain.

They found that the root of morning sickness is a hormone produced by the fetus called GDF15, which appears to act on the mother's brain, causing her to feel nauseous and vomit. How sick a mother-to-be feels depends on how much GDF15 the fetus produces and how much exposure she had to this hormone before becoming pregnant.

The researchers analyzed data on pregnant women from a number of genetic and hormonal studies conducted in cells, mice, and humans. They discovered that GDF15 is made at very low levels by all human tissues. The lead author says the baby growing in the womb is producing a hormone at levels the mother is not used to. He says these findings suggest that exposing women to GDF15 before they conceive may build a tolerance so that morning sickness is never an issue.