Scientists May Have Pinpointed Morning Sickness Cause, Sparking Hope For Potential Cures

Scientists may have discovered the exact cause of morning sickness, the nausea and vomiting that often accompanies pregnancy — and with the discovery, better treatment options could be on the horizon. 

Researchers from the University of Southern California and University of Cambridge found the hormone GDF15 is produced in the placenta and a mother's sensitivity to it determines how severe sickness will be. The study was published Wednesday in Nature.

While previous research has linked GDF15 to these symptoms, the latest study shows women who are exposed to lower levels of the hormone before pregnancy experience more severe symptoms. 

"We now know that women get sick during pregnancy when they are exposed to higher levels of the hormone GDF15 than they are used to," Marlena Fejzo, a clinical assistant professor of population and public health sciences in the Center for Genetic Epidemiology at the USC's Keck School of Medicine and the paper's first author, said in a news release.

Could it lead to a morning sickness cure?

While there have been treatments to help the symptoms of morning sickness, this research opens doors to potential avenues for solving the underlying cause. 

With the study's findings in mind, researchers suggest there are two possible routes for helping: Lowering GDF15, or exposing the person to GDF15 prior to pregnancy in order to prepare them for elevated levels of the hormone once pregnant.

"This study provides strong evidence that one or both of those methods will be effective in preventing or treating" hyperemesis gravidarum, or severe morning sickness, Fejzo said. 

Pre-exposing someone to the hormone would have to be done "safely and slowly in a way that doesn't make them feel miserable," explains University of Cambridge's professor Sir Stephen O'Rahilly, who was also part of the study. "Then we can, we hope, reduce the risk of them developing hyperemesis in the pregnancy."

How long does morning sickness last?

A potential cure could help the 70 to 80% of pregnant people who experience morning sickness, which despite its name, can happen at any point of the day. 

Most women with nausea and vomiting during pregnancy have symptoms in the first trimester or first three months of pregnancy, but a small percentage of women experience prolonged symptoms up until delivery.

Hyperemesis gravidarum is extreme or severe morning sickness, according to the Centers for Disease Control and Prevention, and refers to persistent nausea and vomiting during pregnancy that occurs in about 0.3 to 2% of all pregnancies.

Severe cases can lead to weight loss and dehydration, and may require intensive treatment, according to the CDC.

For Charlotte Howden, experiencing hyperemesis gravidarum during pregnancy with her son seven years ago was "a living hell," she told CBS News.

"Vomiting up to 30 times a day. I couldn't eat anything," she described. "It got really serious for me when I was unable to keep water down anymore."

Britain's Kate, Duchess of Cornwall and actress Amy Schumer have also shared their struggles with the condition.