New Insights on Severe Pregnancy Nausea
A significant genetic study has uncovered a link between a severe form of nausea and vomiting during pregnancy, known as hyperemesis gravidarum (HG), and ten specific genes. Among these, one gene appears to play a major role in this condition.
While many experience mild nausea during the early stages of pregnancy, it’s estimated that up to 10.8% of individuals suffer from such intense symptoms that they can’t eat or drink, sometimes requiring hospitalization. Currently, there are no FDA-approved treatments for HG, which can persist throughout pregnancy.
In a recent publication in the journal Nature Genetics, researchers suggest that the gene responsible for the hormone growth differentiation factor 15 (GDF15) is a primary factor behind HG, which aligns with previous studies.
Additionally, the research identified six more genes related to HG, including one that might influence glucagon-like peptide-1 (GPL-1), a hormone important for regulating insulin and appetite. This gene is also considered a major genetic risk factor for type 2 diabetes.
These findings could lead to new treatment approaches for HG. According to Marlena Fejzo, a study co-author and HG expert at the Keck School of Medicine, this research could open up pathways for more effective prediction, diagnosis, and treatment of HG.
Exploring the Genetic Links
Traditionally, the pregnancy hormone human chorionic gonadotropin (hCG) was blamed for HG due to its sharp rise in early pregnancy, while estrogen has also been suspected as a possible contributor. However, Fejzo’s team has shifted focus to the role of GDF15 as a likely cause.
The study drew on data from nine independent HG studies from the U.S. and Europe. Researchers analyzed the genomes of nearly 11,000 people diagnosed with HG and over 420,000 individuals who had experienced pregnancy without HG. Although most participants were of European ancestry, the study also included diverse populations, which is crucial for validating the findings.
Ultimately, the study identified ten genes associated with increased HG risk, prominently featuring the GDF15 gene across various populations. While these findings indicate a strong correlation, Fejzo emphasizes that more research is needed to establish causation definitively.
Interestingly, the study also highlighted an association with TCF7L2, a gene linked to type 2 and gestational diabetes. This connection opens new avenues for potentially developing medications targeting HG.
Identifying these genes will provide a richer understanding of HG’s complexities. For instance, some genes found are linked to functions like learning and memory, though it’s unclear how this relates to the severe food aversions typical in HG cases.
Fejzo and her team are preparing to initiate a clinical trial soon, planning to administer metformin—a diabetes medication known to elevate GDF15—to patients who have previously experienced HG. The aim is to see if this could reduce nausea and vomiting in future pregnancies.
In the meantime, those affected by HG can seek support and resources through the Hyperemesis Education and Research Foundation, where Fejzo serves as a board member and research director.
