Observational study identifies 10 genetic associations with hyperemesis gravidarum — Evidence Review
Published in Nature Genetics, by researchers from Keck School of Medicine of USC, international collaborators
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Table of Contents
A large, multi-ancestry genetic study has identified ten genes associated with hyperemesis gravidarum, the most severe form of pregnancy sickness, providing new insights into its biological causes. These findings from the Nature Genetics publication are consistent with earlier research highlighting genetic and hormonal factors as primary contributors to this condition.
- Multiple prior studies have established a strong genetic component to hyperemesis gravidarum, with familial and twin studies showing increased risk among first-degree relatives and supporting the significance of genetic predisposition 2 4.
- Earlier genome-wide association studies (GWAS) had already implicated GDF15 and IGFBP7 in hyperemesis gravidarum, and the new study both confirms and expands on these associations by identifying six additional genes involved in hormone signaling, appetite, and metabolism 1 5.
- Recent mechanistic and observational research further supports a causal role for GDF15, showing that both fetal production and maternal sensitivity to this hormone influence the risk and severity of pregnancy sickness 3.
Study Overview and Key Findings
Hyperemesis gravidarum (HG) has long been a challenging and often misunderstood pregnancy complication, with severe nausea and vomiting sometimes leading to malnutrition and significant health risks for both mother and child. While once attributed to psychological factors, accumulating evidence now points to strong genetic and hormonal underpinnings. This new large-scale, international genetic study is timely because it not only confirms known genetic drivers but also uncovers additional genes that may explain individual differences in HG susceptibility and response to treatment. The inclusion of diverse ancestry groups increases the potential generalizability of the findings.
| Property | Value |
|---|---|
| Study Year | 2026 |
| Organization | Keck School of Medicine of USC, international collaborators |
| Journal Name | Nature Genetics |
| Authors | Marlena Fejzo, Xinran Wang, Qing Tan, Julia Zöllner, Natàlia Pujol-Gualdo, Triin Laisk, Estonian Biobank Research Team, Sarah Finer, David A. van Heel, Genes & Health Research Team, Ben Brumpton, Laxmi Bhatta, Kristian Hveem, Elizabeth A. Jasper, Digna R. Velez Edwards, Jacklyn N. Hellwege, Todd Edwards, Gail P. Jarvik, Yuan Luo, Atlas Khan, Kimber MacGibbon, Yuan Gao, Gaoxiang Ge, Inna Averbukh, Erin Soon, Michael Angelo, Per Magnus, Stefan Johansson, Pål R. Njølstad, Artem Kim, Steven Gazal, Marc Vaudel, Chang April Shu, Nicholas Mancuso |
| Population | Women with hyperemesis gravidarum + controls |
| Sample Size | 10,974 women with HG, 461,461 controls |
| Methods | Observational Study |
| Outcome | Genetic associations with hyperemesis gravidarum |
| Results | Identified 10 genes linked to hyperemesis gravidarum. |
Literature Review: Related Studies
To understand how the new findings fit within the broader research landscape, we searched the Consensus database, which indexes over 200 million scientific papers. The following search queries were used:
- hyperemesis gravidarum genetic factors
- genes pregnancy sickness association
- maternal health genetic predisposition studies
| Topic | Key Findings |
|---|---|
| What genetic factors contribute to hyperemesis gravidarum and pregnancy sickness? | - GDF15 and IGFBP7, both involved in placentation and appetite regulation, are strongly associated with hyperemesis gravidarum; familial aggregation studies confirm a significant genetic component 1 2 4 5. - Recent GWAS and mechanistic studies implicate maternal sensitivity to GDF15 and expand the list of risk genes, including new candidates linked to hormone signaling and metabolism 1 3 5. |
| How do identified genetic factors interact with maternal and fetal physiology? | - Elevated maternal blood levels of GDF15, primarily derived from the feto-placental unit, are linked to increased risk of nausea and vomiting in pregnancy, and maternal GDF15 sensitivity is a major determinant of symptom severity 3 5. - The maternal genotype appears to have a greater influence than the fetal genotype, though both contribute to risk 3 4. |
| Are there links between hyperemesis gravidarum genetics and other pregnancy complications? | - Several genes associated with HG are also implicated in preeclampsia and other gestational disorders, suggesting overlapping pathways in placental function and maternal adaptation 6 7 8 10 13. - Polygenic risk scores and GWAS identify shared genetic loci affecting both HG and hypertensive pregnancy complications 8 10. |
| What are the clinical implications for diagnosis, prediction, and treatment? | - Early measurement of GDF15 and IGFBP7 may aid in the diagnosis and risk prediction of HG; current treatments often provide only partial relief, and new genetic findings may inform personalized therapy 1 5. - Mechanism-based approaches, such as modulating GDF15 levels or maternal sensitivity, are under investigation as potential preventive or therapeutic strategies 3 5. |
What genetic factors contribute to hyperemesis gravidarum and pregnancy sickness?
The recent study's identification of ten genes, including both previously known (e.g., GDF15, IGFBP7) and newly identified candidates, aligns with a robust body of evidence supporting a genetic basis for hyperemesis gravidarum. Familial aggregation studies demonstrate increased risk among first-degree relatives, and earlier GWAS have pointed to the significance of placentation and appetite-regulating genes. The expansion to multi-ancestry cohorts and identification of additional loci in the new study enhance the understanding of biological diversity in HG susceptibility 1 2 4 5.
- Multiple GWAS and observational studies consistently implicate GDF15 and IGFBP7 in HG, confirming the genetic contribution to disease risk 1 5.
- Familial clustering, including higher risk in sisters and daughters of affected women, supports a hereditary component 2 4.
- The new study confirms previously reported loci and introduces new genetic candidates, broadening the range of implicated biological pathways 1.
- Genetic research increasingly points to specific hormone and metabolism-related genes, offering new directions for understanding pathophysiology 1 3.
How do identified genetic factors interact with maternal and fetal physiology?
Research increasingly indicates that both maternal and fetal physiology play key roles in HG, with maternal genotype exerting a stronger influence. GDF15, produced by the feto-placental unit, acts on the maternal brainstem to trigger nausea and vomiting. Maternal sensitivity to GDF15, influenced by genetic variants, modulates symptom severity and risk. These mechanisms are supported by both genetic association and mechanistic studies 3 4 5.
- High maternal GDF15 levels correlate with greater risk of pregnancy nausea and HG 3.
- Maternal genetic predisposition appears more influential than fetal genetics, though both contribute 4.
- Chronic pre-pregnancy exposure to GDF15 (as in β-thalassaemia) is associated with lower rates of HG, suggesting desensitization mechanisms 3.
- Newly identified genes in the recent study may further clarify how metabolic and hormonal pathways interact to produce HG symptoms 1.
Are there links between hyperemesis gravidarum genetics and other pregnancy complications?
Several genetic studies reveal shared pathways between HG and other pregnancy complications such as preeclampsia. GWAS have identified overlapping loci involved in angiogenesis, placental development, and blood pressure regulation, indicating that maternal adaptation to pregnancy is influenced by a common set of genetic factors. The new study's findings of associations with pregnancy length and preeclampsia-related genes reinforce this view 6 7 8 10 13.
- Genes near FLT1 and INHBB, implicated in preeclampsia, are also involved in placental and hormonal regulation relevant to HG 6 7 8.
- Polygenic risk scores for hypertension and preeclampsia overlap with those for HG, suggesting some shared genetic architecture 8 10.
- The identification of PGR and other placental genes in both HG and preeclampsia highlights possible mechanistic connections 1 8.
- Understanding these links may improve risk prediction and inform preventive strategies for multiple pregnancy complications 8 10.
What are the clinical implications for diagnosis, prediction, and treatment?
The integration of genetic findings into clinical practice may improve early diagnosis, risk prediction, and personalized treatment for HG. Early measurement of hormones such as GDF15 and IGFBP7 can distinguish HG from less severe pregnancy nausea and aid in prognosis. While current pharmacologic treatments provide limited relief for many patients, targeting the underlying genetic and hormonal pathways offers the possibility of more effective, individualized interventions 1 3 5.
- Serum GDF15 and IGFBP7 levels at 12 weeks can help predict and diagnose HG 5.
- Mechanistic studies suggest that modulating GDF15 signaling or maternal sensitivity could reduce symptom severity 3 5.
- New genetic risk loci may enable tailored therapies, including matching existing drugs to patient profiles or developing novel interventions 1 3.
- Clinical trials, such as those testing metformin for GDF15 modulation, represent promising avenues for mechanism-based prevention and treatment 3.
Future Research Questions
Continued research is essential to further unravel the complex genetic, hormonal, and environmental factors underlying hyperemesis gravidarum and related pregnancy complications. Large, multi-ancestry cohorts and integrative analyses will be crucial to refine risk prediction, understand gene-environment interactions, and translate genetic findings into effective therapies.
| Research Question | Relevance |
|---|---|
| How do the newly identified genes contribute to the pathophysiology of hyperemesis gravidarum? | Determining the functional roles of these genes will clarify biological mechanisms and identify intervention points for treatment 1 3. |
| Can modulating GDF15 levels or maternal sensitivity prevent or treat hyperemesis gravidarum? | Mechanistic studies and early clinical trials suggest this is a promising therapeutic strategy, but more evidence is needed from interventional studies 3 5. |
| Are there shared genetic pathways between hyperemesis gravidarum and other pregnancy complications such as preeclampsia? | Overlapping genetic loci suggest common biological mechanisms, and understanding these could help risk stratification and prevention for multiple disorders 6 8 10. |
| What is the role of gene-environment interactions in the development and severity of hyperemesis gravidarum? | Environmental factors may modulate genetic risk, and understanding these interactions is vital for personalized prevention and treatment strategies 2 4. |
| Can genetic screening improve early diagnosis and personalized treatment of hyperemesis gravidarum? | Integrating genetic risk profiles into clinical practice could enable earlier intervention and more effective, individualized therapy, but clinical utility must be demonstrated 1 5. |