Scientists Find Main Cause of Extreme Pregnancy Nausea

Millions of pregnant people who suffer through extreme nausea and vomiting may soon have real treatment options, thanks to a major scientific breakthrough.

Researchers have identified 10 genes linked to hyperemesis gravidarum (HG), the most severe form of pregnancy nausea. One gene stands out as the main culprit: GDF15, which produces a hormone that appears to trigger the debilitating symptoms.

The condition affects up to 10% of pregnant people and is far more severe than typical morning sickness. People with HG often can't eat or drink and may need hospitalization. The nausea can last throughout the entire pregnancy, yet no FDA-approved treatments currently exist.

"It's going to be helpful as far as exploring new avenues for therapies," said lead researcher Marlena Fejzo from the University of Southern California's Keck School of Medicine. Her team compared genetic data from nearly 11,000 people with HG to over 420,000 people who had pregnancies without the condition.

The study included participants from diverse backgrounds across the U.S. and Europe. While most were of European descent, the research also included people of Asian, African, and Latino ancestry to ensure the findings apply broadly.

GDF15 emerged as the top signal across all populations studied. The team also discovered something unexpected: a link to TCF7L2, a gene connected to diabetes and the same hormone that drugs like Ozempic mimic.

The Bright Side

This research overturns decades of misunderstanding about what causes severe pregnancy nausea. For years, doctors blamed pregnancy hormones like hCG and estrogen, but this study found no genetic links to those hormones.

The findings open exciting new paths for drug development. Pharmaceutical companies are already testing GDF15-targeting medications that could provide relief to the millions who suffer through this condition.

Dr. Andrew Housholder, an emergency physician specializing in HG, called the research "incredibly well-done" and said it "cements" GDF15 as the primary driver of the condition. The discovery also validates the experiences of countless people whose suffering was dismissed as normal pregnancy symptoms.

Beyond GDF15 treatments, the newly identified genes offer additional targets for future therapies. Some are linked to appetite and metabolism, giving researchers multiple avenues to explore.

For pregnant people currently battling extreme nausea with few options, this breakthrough represents real hope on the horizon.