New Study Finds Possible Cause Of Extreme Morning Sickness

For anyone who has ever experienced extreme morning sickness, you know how difficult it is to manage. The exhaustion, the dehydration, the constant nausea. And perhaps most of all, the helpless feeling that comes when you don’t quite know where the morning sickness is coming from or when it might end. A new study might shift that horrible feeling for many pregnant women experiencing extreme morning sickness, because scientists believe they have pinpointed the cause.

A new study published in Nature — conducted by researchers from the University of Southern California, the University of Pennsylvania, and Cambridge University — hopes to provide better treatment for pregnant women suffering from hyperemesis gravidarum, an extreme form of morning sickness that causes intense nausea and vomiting. Researchers concluded that a particular hormone, called GDF-15, released by growing fetuses could be triggering this reaction in women who are more sensitive to the hormone in the early stages of their pregnancy and a woman’s prior exposure to the hormone. Approximately two-thirds of women experience some form of morning sickness, but this new study found that the amount of GDF-15 circulating in a pregnant woman’s blood could determine the severity of her sickness.

Until now, pregnant women were unable to find any real treatment beyond trying to lessen their symptoms, and it was truly untenable. Hyperemesis gravidarum can be so severe in some people that it can end up with trips to the hospital for dehydration. Several pregnant celebrities like Kate Middleton and Amy Schumer have been hospitalized for dehydration caused by hyperemesis gravidarum, and their experiences have helped to raise the profile of this serious issue.

“For the first time, hyperemesis gravidarum could be addressed at the root cause, rather than merely alleviating its symptoms,” Tito Borner, a physiologist at the University of Pennsylvania, explained in Nature. If GDF-15 can be blocked by giving pregnant women at a higher risk antibodies, this could be the key to alleviating extreme morning sickness.

Hyperemisis gravidarum can have other consequences beyond nausea and vomiting, increasing the risk of preterm birth, pre-eclampsia, and blood clots, which put both the mother and the fetus at risk. Despite this serious risk, studying the root cause of extreme morning sickness was not widely done until recently. “I’ve been working on this for 20 years and yet there are still reports of women dying from this and women being mistreated,” Dr. Marlena Fejzo, a geneticist at the University of Southern California Keck School of Medicine and a co-author of the new study, told The New York Times.

“If fetally derived GDF15 is a primary driver of nausea and vomiting during pregnancy, then that’s a big deal,” nutritional researcher Bart De Jonghe at the University of Pennsylvania in Philadelphia explained in Nature. “It shows us a powerful way the fetal environment can use a single chemical signal to dramatically impact maternal health and behaviour.”

Studies referenced:

Fejzo, M., Rocha, N., Cimino, I. et al. (2023) GDF15 linked to maternal risk of nausea and vomiting during pregnancy. Nature. https://doi.org/10.1038/s41586-023-06921-9