Largest study of pregnancy sickness uncovers six new genetic links

The study, which analyzed DNA from more than 10,000 women, identified a total of 10 genes linked to the most severe form of pregnancy sickness, hyperemesis gravidarum, pointing to biological mechanisms behind it and potential new treatment pathways.

Keck School of Medicine of USC

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The USC research team that recently identified the hormone-encoding gene GDF15 as a key driver of pregnancy sickness has identified 9 additional genes linked to its most severe form, hyperemesis gravidarum (HG).  Six of these genes had not been previously linked to the condition. 

HG, which affects about 2% of women, causes nausea and vomiting so severe that eating can become extremely difficult.  The condition was long misunderstood and often dismissed as psychological. But growing evidence shows it has a strong biological and genetic basis and can lead to severe malnourishment, putting both mother and baby at risk.

In the largest genetic study of HG to date, researchers from the Keck School of Medicine of USC and their international collaborators analyzed data from 10,974 women with the condition and 461,461 controls across European, Asian, African and Latino ancestries. The findings, just published in Nature Genetics, offer new clues about the condition and new hope for those affected.

“Because this is the largest study of HG ever conducted, we’ve been able to tease out important new details that were previously unknown,” said Marlena Fejzo, PhD, a clinical assistant professor of population and public health sciences in the Center for Genetic Epidemiology at the Keck School of Medicine, who led the present study and earlier research linking GDF15 to HG. “The fact that we’ve studied women from multiple ancestry groups suggests that these results may be generalizable across a broad population.”

The researchers identified 10 genes linked to HG—four previously identified and six new. The strongest link by far was to growth differentiation factor 15 (GDF15), a gene that produces a hormone of the same name, which rises sharply during pregnancy. Earlier research by Fejzo  and an international team showed that the link lies in women’s sensitivity to the hormone: Women exposed to lower levels of the hormone before pregnancy because of a mutation in the gene experience more severe symptoms, while women exposed to higher levels of the hormone before pregnancy have less severe nausea and vomiting symptoms.

The other genes identified relate to key pregnancy hormones, appetite and nausea, insulin and metabolism, how the brain learns and adapts, and certain pregnancy outcomes.

“Now that we’ve more than doubled the genes associated with HG, we can dig deeper into the biology behind this condition, as well as new possible pathways for treating it,” Fejzo said.

The genetic basis of HG

The researchers conducted a genome-wide association study (GWAS), scanning the entire genome for differences between women who developed HG during pregnancy and those who did not.

The four genes previously identified were GDF15; GFRAL, which produces the receptor for the GDF15 hormone; and IGFBP7 and PGR, both of which are involved in development of the placenta.

The six newly identified genes offer further clues that might help explain the basis of HG or point to new ways of treating it. They include FSHB, TCFL72 SLITRK1, SYN3, IGSF11 and CDH9.

TCF7L2 stands out because it is one of the strongest genetic risk factors for type 2 diabetes and is also associated with gestational diabetes. It may influence glucagon-like peptide-1 (GLP-1), a gut hormone that controls blood sugar and can influence appetite and nausea.

“This is a brand-new target, and it’s not yet clear what it’s doing in pregnancy,” Fejzo said.

Several of the other genes identified are involved in appetite and nausea, as well as brain plasticity, or how the brain learns and adapts to new information. Fejzo suggests the brain may learn to associate certain foods with feeling sick, leading to strong, lasting aversions during pregnancy. More research is needed to explore this possibility.

The researchers also found that some genes linked to HG were associated with other pregnancy outcomes, including shorter pregnancy length and preeclampsia, a serious blood pressure condition. 

Treating pregnancy sickness

Several medications are available for treating HG, but even the most effective, Zofran, only partly relieves symptoms for about half of patients. The findings reveal new potential treatment targets and could possibly also help match existing medications to patients based on their genetic profiles.

Fejzo and her team just received approval to launch a clinical trial of metformin, a widely used diabetes medicine that increases GDF15 levels. The study will test whether taking metformin before pregnancy can desensitize women to the hormone, potentially reducing nausea and vomiting or preventing HG in women who have had it before.

About this research

In addition to Fejzo, the study’s other authors are Xinran Wang, Qing Tan, Artem Kim, Steven Gazal, Chang Shu and Nicholas Mancuso from the Department of Population and Public Health Sciences and the Center for Genetic Epidemiology, Keck School of Medicine of USC, University of Southern California; Julia Zöllner, Sarah Finer and David A. van Heel from Queen Mary University of London, London, United Kingdom; Natàlia Pujol-Gualdo and Triin Laisk from the University of Tartu, Tartu, Estonia; the Estonian Biobank Research Team; the Genes & Health Research Team; Ben Brumpton, Laxmi Bhatta and Kristian Hveem from the Norwegian University of Science and Technology, Trondheim, Norway; Elizabeth A. Jasper, Digna R. Velez Edwards, Jacklyn N. Hellwege and Todd Edwards from Vanderbilt University Medical Center, Nashville, Tennessee; Gail P. Jarvik from the University of Washington Medical Center, Seattle, Washington; Yuan Luo from Northwestern University, Chicago, Illinois; Atlas Khan from Columbia University, New York, New York; Kimber MacGibbon from the Hyperemesis Education and Research Foundation, Clackamas, Oregon; Yuan Gao and Gaoxiang Ge from the Chinese Academy of Science, Shanghai, China; Inna Averbukh, Erin Soon and Michael Angelo from Stanford University, Stanford, California; Per Magnus from the Norwegian Institute of Public Health, Oslo, Norway; Stefan Johansson, Pål R. Njølstad and Marc Vaudel from the University of Bergen, Bergen, Norway.

This work was supported by federal and private agencies across the world, including the National Institutes of Health, under grants R01HG012133, R01CA258808, R01GM140287 and U54HG013243. A full list of funders can be found in the online publication. 

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Journal

Nature Genetics

DOI

10.1038/s41588-026-02564-4 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Multi-ancestry genome-wide association study of severe pregnancy nausea and vomiting

Article Publication Date

14-Apr-2026

COI Statement

The authors declare the existence of financial/non-financial competing interests. MF: Hyperemesis Education and Research (HER) Foundation (voluntary Board member and Research Director); Harmonia Healthcare (CSO, stock, paid consultant); NGM Biosciences (stock, paid consultant); Foundation for Women's Health (voluntary Board member); The Morning Sickness Clinic, voluntary Chief Scientific Officer). The remaining authors declare no competing interests.

 

Why extended postpartum Medicaid coverage during pandemic led to gains in enrollment

Emergency provisions offered enhanced federal funding to states in exchange for pausing disenrollment, reducing disruptions in coverage for postpartum care

Rutgers University

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The federal policy requiring states to keep Medicaid beneficiaries enrolled during the COVID-19 pandemic extended postpartum Medicaid coverage nationwide and sharply increased the number of individuals remaining insured after childbirth, according to a Rutgers Health researcher.

 

An analysis, published in The Milbank Quarterly, of Medicaid claims in 15 states finds that this coverage expansion produced modest changes in health care use, with notable increases in emergency department visits and mental and behavioral health diagnoses.

 

“Medicaid claims data provide us with important insights into service utilization and maternal health outcomes,” said Erica Eliason, an assistant professor at the Rutgers Center for State Health Policy and the Rutgers School of Public Health and lead author of the analysis. “Yet because we typically rely on claims data, which show us what care was billed, we do not necessarily know whether individuals understood that they remained covered or what barriers they may have faced in seeking care.”

 

The Families First Coronavirus Response Act’s continuous coverage requirement offered enhanced federal funding to states in exchange for pausing disenrollment and produced greater insurance continuity for postpartum individuals.

 

This study, which involved nearly 489,000 postpartum individuals, examined how extended eligibility under the act affected Medicaid enrollment, continuity of coverage and use of Medicaid-paid health care from three to 12 months after childbirth – a period not previously covered for those insured through pregnancy Medicaid.

 

It compared postpartum Medicaid outcomes during the pandemic-era continuous coverage period with outcomes from a year earlier.

 

The share of individuals maintaining Medicaid coverage through 12 months postpartum increased to 77% from 37% before the Families First Coronavirus Response Act during its implementation.

 

In the three- to 12-month postpartum period, when pregnancy Medicaid would usually have ended, extended eligibility was associated with more Medicaid-paid emergency department visits and a higher proportion of individuals receiving services with mental or behavioral health diagnoses.

 

However, the analysis did not identify increases in outpatient visits or pregnancy-related diagnoses during the extended coverage period. For example, although extended eligibility increased emergency department use by about 107 visits per 1,000 beneficiaries, outpatient visits did not show statistically significant changes.

 

Eliason said it is difficult to determine whether beneficiaries sought care outside Medicaid, whether awareness of continued coverage influenced care-seeking or how pandemic-related service disruptions shaped overall care utilization.

 

The authors of the analysis emphasized the importance of taking a patient-centered approach to extending postpartum coverage. They said the 49 states that have adopted 12-month postpartum coverage should pair the extension with communication and outreach strategies to ensure individuals are aware of and able to use their postpartum Medicaid coverage.

 

“I would advise policymakers that continuous postpartum coverage is an important tool for states to monitor and improve health outcomes for postpartum people and their babies,” Eliason said. “But without strong communication and support, expanded eligibility may not fully translate into improved access or outcomes.”

 

The study’s authors, based at Rutgers and the University of Maryland, called for future research examining postpartum coverage and health outcomes for additional populations, over longer periods of time and under stable public health conditions.

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Journal

The Milbank Quarterly

DOI

10.1111/1468-0009.70079 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Extended Pregnancy Medicaid During COVID-19 and Enrollment and Health Care Use in the Postpartum Year

 

$1 million U.S. Department of Justice grant will support virtual reality training for domestic violence response

A George Mason College of Public Health team will work with law enforcement and domestic violence prevention experts to reduce risks for first responders and victims.

George Mason University

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Domestic violence 911 calls often place first responders in the midst of crisis and confusion. The scene may involve conflicting stories, visible injuries, frightened children, and little clarity about what just happened. 

At George Mason University, researchers have secured more than $1 million in federal funding to help frontline professionals prepare for these complex moments. The grant from the U.S. Department of Justice will help fund a novel virtual reality training program to strengthen interprofessional responses to domestic violence. 

Social work professors Denise Hines and Holly Matto will co-lead the one-year project in the College of Public Health, partnering with local law enforcement, domestic violence organizations, and health care providers in Northern Virginia to design and pilot the training. The team also includes social work assistant professors Michelle Hand and Anna Parisi as co-investigators, and Bethany Cieslowski, chief innovation officer for immersive technologies. 

The faculty members, as well as College of Public Health Dean Melissa J. Perry, expressed gratitude to U.S. Senators Mark R. Warner and Tim Kaine of Virginia for their support of the congressional funding, and to the Department of Justice for administering the $1,026,029 award through its Byrne Justice Assistance Grants program. 

“We’re thankful for the leadership and support to bring the power of virtual reality to improve health and safety,” Perry said. “Virginia will lead the way in coordinated, prevention-focused responses to domestic violence. Looking ahead, the model developed here can one day help communities across the country.” 

Using technology and resources in the College of Public Health’s Lab for Immersive Technologies and Simulation, the project team will build VR case scenarios that reflect the complexities of domestic violence calls. The simulations will allow frontline professionals to practice coordinated responses and experiment with different approaches before facing similar situations in real life. 

“The innovation here is bringing together professionals like law enforcement, social workers, and health care providers to co-design new VR cases that are relevant to challenges on the ground,” Matto said. 

Domestic violence remains a public health and safety crisis. In Virginia alone, the statewide domestic and sexual violence hotline received more than 70,000 calls in 2023. Family and intimate partner violence accounts for roughly one-third of all homicides in the state annually. And for first responders, these calls can also be among the most volatile and unpredictable situations they encounter. 

“Domestic violence calls are some of the toughest calls, but also some of the most common calls that law enforcement will come across,” said Hines, the Elisabeth Shirley Enochs Endowed Professor of Social Work. “They're often coming in at a precarious and dangerous moment.” 

 

UC Irvine physicists discover method to reverse ‘quantum scrambling’

The work addresses the problem of information loss in quantum computing system

University of California - Irvine

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Irvine, Calif., April 13, 2026 — Quantum computers stand to revolutionize research by helping investigators solve certain problems exponentially faster than with conventional computers. Current quantum computers encounter a challenge where they lose stored information in a process known as ‘quantum scrambling.’ However, scientists at the University of California, Irvine discovered a method to enable computers to preserve the data that would otherwise be lost during the scrambling process.

“My work is on understanding how this scrambling of quantum information works and in understanding how it emerges,” said Thomas Scaffidi, assistant professor of physics & astronomy and lead author of the new Physical Review Letters study. “We’re trying to figure out if the information is still there in some form and if we can reverse the scrambling process completely.”

The fundamental unit of information in quantum computing is the qubit. Conventional computers use bits, which store information as either a 0 or a 1, while a qubit stores information as either a 0, a 1 or both at the same time.

Quantum scrambling happens when information encoded into qubits spreads within a quantum computing chip and then keeps spreading before disappearing entirely.

“Let’s say you have many qubits that are all talking to each other and exchanging information,” said Scaffidi. “If you try to locally encode some information in the qubits, after a while, there’s going to be the scrambling effect – the encoded information is going to spread out over many qubits and will be effectively lost, and you won’t be able to recover it. That’s an issue if you want to retrieve that information or do calculations with it.”

Scaffidi and his graduate student, Rishik Perugu, approached the problem by studying a subtle feature of quantum physics: Although scrambled quantum information can appear effectively lost, the underlying microscopic laws are in principle often reversible. That means the information may not be destroyed but dispersed in an extremely complex way across many interacting particles.

“At the microscopic level, our universe seems to be reversible in time, so if you think of two particles colliding, if you watch a movie of two particles colliding, the movie would look sensible if you played it forward or backwards,” said Scaffidi.

Perugu discovered that this reversible behavior appears in many quantum systems, including quantum computers. That opens the door to counteracting quantum scrambling with a precisely tuned intervention that effectively drives the system backward, allowing previously dispersed information to refocus near where it started.

“It happens to be a very universal property,” Scaffidi said. “The conclusion is that it is possible to reverse it, but it requires an extremely fine-tuned and very fine level of control on your system.”

The breakthrough came after Perugu, soon after joining Scaffidi’s research group, was able to perform the calculations revealing how quantum scrambling might be reversed.

“The project had stalled for a while before Rishik joined,” said Scaffidi. “His work gave it new momentum, and he played a central role in making the new paper happen.”

Scaffidi is funded by a U.S. Department of Energy Early Career Research Program Award, and key collaborators include Michael Flynn at BlocQ and Bryce Kobrin at Google.

About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.

Media access: Radio programs/stations may, for a fee, use an on-campus studio with a Comrex IP audio codec to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at https://news.uci.edu/media-resources.

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Journal

Physical Review Letters

DOI

10.1103/bt23-4y1t 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Krylov Winding and Emergent Coherence in Operator Growth Dynamics

Article Publication Date

13-Apr-2026

 

Rice study resolves decades-old mystery in organic light-emitting crystals

Findings reveal how molecular defects can enhance light conversion efficiency

Rice University

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Materials that emit and manipulate light are at the heart of technologies ranging from solar energy to advanced imaging systems. But even in well-studied materials, some fundamental behaviors remain unexplained.

Researchers at Rice University have now solved a long-standing mystery in a widely used organic semiconductor, revealing how tiny structural imperfections can actually improve how these materials work.

In a study published in the Journal of the American Chemical Society, the team investigated 9,10-bis(phenylethynyl)anthracene (BPEA), a model system for studying how light energy moves through materials. For years, scientists have observed unusual optical behavior in BPEA, specifically two distinct absorption and emission signals that did not match existing theories. 

“This was a long-standing puzzle in the field,” said Colette Sullivan, a doctoral student in Rice’s Department of Chemistry and co-author of the study. “Once we connected the experimental results with theory, it became clear the two signals were coming from completely different processes.”

To understand this behavior, the researchers combined spectroscopy experiments with advanced simulations. Their findings show that the material’s unusual light absorption comes from interactions between two types of excited states — excitons, which carry energy through the material, and charge-transfer states, where electrons shift between molecules.

But the biggest surprise came from the material’s light emission.

Instead of originating purely from the crystal itself, the team found that the lower-energy light emission comes from tiny structural defects, small irregularities where molecules form X-shaped pairs. These defects act as energy localization sites, or trap states, that behave differently from the rest of the material. 

“These defects aren’t just imperfections, they actually create new pathways for energy flow, essentially turning apparent flaws into desirable features,” said Lea Nienhaus, associate professor of chemistry and member of the Rice Advanced Materials Institute. 

Theoretical studies led by postdoctoral scientist Jakub Sowa showed that rather than reducing performance, these defect sites actually enhanced a process called triplet-triplet annihilation, which allows materials to convert lower-energy light into higher-energy light. At the same time, they suppress competing energy pathways that would otherwise reduce efficiency.

The result is a material where imperfections can actually improve how energy is converted and emitted.

The findings challenge a long-held assumption in materials science that defects are inherently detrimental. Instead, they suggest that carefully controlling these imperfections could become a powerful design strategy. 

“Our work shows that material defects can actually improve performance, creating a target for materials engineering,” said Peter J. Rossky, the Harry C. and Olga K. Wiess Chair in Natural Sciences Emeritus at Rice. “By understanding how molecular structure, disorder and electronic interactions work together, we can begin to design materials where these effects are not just tolerated but deliberately used to control how energy moves.”

This insight could help researchers design more efficient materials for applications in solar energy, optoelectronics and light-based sensing technologies. By intentionally tuning how molecules pack together and where defects form, scientists may be able to create materials that convert and control light more efficiently than ever before.

The research was supported by the National Science Foundation (DMR-2517590), the Camille and Henry Dreyfus Foundation (TC-23-050) and the Alfred P. Sloan Foundation (FG-2024-22474). Additional support was provided by Rice and the NOTS cluster operated by Rice’s Center for Research Computing. The authors also acknowledge the Martí Group for its support.

 

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Journal

Journal of the American Chemical Society

DOI

10.1021/jacs.6c03064 

Method of Research

Experimental study

Article Publication Date

4-Apr-2026