Insight
Study reveals potential causes of infertility
A 556-gene signature in the uterine lining may help explain why some embryo transfers fail, even when clinics use chromosomally normal embryos, new research suggests.
Even in the best-case scenario, when clinics transfer embryos with a normal number of chromosomes into a woman’s uterus, only about half result in a live birth.
Some transfers lead to pregnancy followed by miscarriage, but in 30 to 35 per cent of cases the embryo does not implant in the uterus at all.
For decades, fertility research has focused heavily on embryo quality, but some scientists suspect the problem can lie in the uterus itself. New findings support that view.
Researchers at Rutgers Health and Michigan State University identified genes concentrated in gland cells in the uterine lining, known as the endometrium, that rise in fertile women during the brief window when the womb can accept an embryo.
The team enrolled 30 patients with regular menstrual cycles and proven fertility.
Participants used ovulation predictor kits and worked with researchers so tissue samples were taken at precise points in the cycle.
Blood hormone levels and microscopic checks were used to confirm timing, adding rigour the researchers said was missing from earlier work.
To track the endometrium’s changing biology, the team used two sequencing approaches: one measuring gene activity across the whole tissue and another measuring it cell by cell. Both pointed to the same pattern.
The biggest molecular shift came as the cycle entered the mid-secretory phase, the stage typically linked with implantation.
The sharpest changes were seen in specialised uterine gland cells that produce molecules thought to nourish an embryo and help coordinate implantation.
Earlier studies had shown these glands matter in mice and sheep, but the authors said this is the first human evidence pointing to a central role for this glandular tissue.
They also noted that their results in mostly Black and Hispanic patients matched findings from mostly white patients in past research, suggesting similar factors may drive infertility across races.
From these patterns, the researchers defined a 556-gene signature they called the Glandular Epithelium Receptivity Module.
When they applied a score based on this signature to published datasets, it was consistently lower in women with recurrent implantation failure or pregnancy loss than in fertile controls.
The work is not yet ready for clinical use.
Nataki Douglas, an associate professor of obstetrics, gynaecology and reproductive health at Rutgers New Jersey Medical School and senior author of the study, said the next steps include shortening the gene list and recruiting patients with implantation failure to test whether the signature predicts outcomes.
“This was one of the first attempts to really look at the menstrual cycle in women who are fertile and try and understand how the endometrium is changing, how it becomes briefly receptive to embryo attachment at the most fundamental level,” Douglas said.
“Once we can identify those who are at risk and the genes that are the most important in this 556, ones that we know code for particular proteins we might be able to add synthetically, then we may be able to work on therapeutic approaches.”
WHIS, the flagship summit uniting leaders across the women’s health and healthcare innovation ecosystem, has just announced that the 2026 edition of the event will be hosted at the Encore Boston Harbor.
The summit will take place October 13-15, 2026, bringing together innovators, investors, policymakers, healthcare providers, payers, and industry partners to accelerate advancements in women’s health and wellbeing.
WHIS continues to build on its mission to foster cross-sector collaboration, deepen strategic partnerships, and drive scalable solutions that improve health outcomes and address persistent gaps in care.
Attendees can expect high-impact keynotes, expert panels, structured networking, and interactive sessions that span consumer health, digital innovation, clinical advances, and lifespan inclusive care.
Set against the backdrop of one of the region’s most dynamic waterfront destinations, WHIS will bring together the full health innovation ecosystem for a multi-day gathering focused on accelerating progress in women’s health, digital transformation, data integration, and scalable care solutions.
Register your interest for the 2026 event at the official event website:
https://whisusa.com/events/whisusa
About WHIS USA
WHIS champions cross-disciplinary collaboration to transform health and wellbeing through innovation, data-driven insights, digital solutions, and community-centred care.
The summit unites the full health ecosystem to co-create sustainable solutions that address unmet needs, enhance member experience, and unlock commercial and clinical impact.
Nighttime temperatures during pregnancy may be linked to a higher chance of an autism diagnosis in children, a recent study suggests.
The research tracked nearly 295,000 mother-child pairs in Southern California from 2001 to 2014 and linked warmer overnight temperatures with higher risk in early and late pregnancy.
Children of mothers exposed to higher than typical nighttime temperatures during weeks one to 10 of pregnancy had a 15 per cent higher risk of an autism diagnosis.
Exposure during weeks 30 to 37 was linked to a 13 per cent higher risk.
Lead author David Luglio, a post-doctoral fellow at Tulane University, said: “A key takeaway is that we identified specific windows when a mother and her developing child can be most affected by exposures to higher nighttime temperatures.
“This is critical and hopefully can help mothers prepare accordingly.”
The study is described as the first to examine how temperature may affect fetal neurodevelopment, the process by which a baby’s brain and nervous system form during pregnancy.
Extreme temperatures linked to increased risk were classified as above the 90th percentile, meaning 3.6°F hotter than average, and the 99th percentile, 5.6°F above average.
The association held even after researchers accounted for factors such as neighbourhood conditions, vegetation and fine-particle air pollution.
The study could not account for other factors such as access to air conditioning. Researchers did not find the same association with daytime temperatures, potentially because people spend more time away from home during the day.
“Heat waves are becoming more frequent, and people may only think of the dangers of daytime heat exposure,” said Mostafijur Rahman, assistant professor of environmental health sciences at Tulane University.
“These results indicate a strong association between high nighttime temperatures during pregnancy and autism risk in children and show that we need to think about exposure to heat around the clock.”
The study did not examine how higher temperatures at night might affect prenatal development, though Luglio said it is possible that warmer nights disrupt sleep for pregnant mothers.
Previous research has suggested insufficient sleep during pregnancy may be linked to a higher risk of neurocognitive delays in children.
“Extreme heat exposure during pregnancy has been linked to a range of adverse health outcomes, including prenatal neurodevelopment delays and complications with an embryo’s development of a central nervous system,” Luglio said.
“The goal of our study was to specifically explore the link between prenatal heat exposure and autism diagnoses for the first time.”
The World Health Organization (WHO) welcomed a delegation of parliamentarians to its Geneva headquarters for a high-level dialogue on women’s health and sexual and reproductive health and rights.
The meeting on 20 January 2026 focused on women’s health, sexual and reproductive health and rights, noncommunicable diseases (long-term conditions such as cancer and diabetes) and global health cooperation.
The exchange was convened by the Konrad-Adenauer-Stiftung and the UNITE Parliamentarians Network for Global Health, bringing together parliamentarians from Albania, Germany, Georgia, Mexico, Slovakia, South Africa, Sri Lanka, Sweden and Zimbabwe.
A central theme was the need to move beyond fragmented approaches to women’s health.
Dr Alia El-Yassir, WHO director for gender, equity and diversity, highlighted that outcomes are shaped by gender inequalities, social norms and structural barriers across the life course, requiring coordinated action across health systems.
Thirty years after the Beijing Declaration and Platform for Action, a landmark framework adopted in 1995 to advance gender equality and women’s rights, Dr Anna Coates, WHO gender equality technical lead, noted that progress on women’s health remains uneven.
She called for health systems that are more gender-responsive and able to address women’s health holistically across the life course.
Parliamentarians stressed that health is inseparable from wider social and economic policies, and called for stronger links between evidence, legislation and measurable impact at country level.
The meeting also focused on sexual and reproductive health and rights, where parliamentarians expressed interest in engaging on issues that directly affect their constituents.
Dr Pascale Allotey, director of WHO’s Department of Sexual, Reproductive, Maternal, Child, Adolescent Health and Ageing, outlined WHO’s life-course approach to sexual and reproductive health and rights.
She highlighted how needs evolve from birth to older age and how these are shaped by social determinants, humanitarian crises and demographic trends.
Dr Allotey underscored the role of parliamentarians in advancing sexual and reproductive health and rights and the importance of continued engagement with WHO to support evidence-based policy-making.
The agenda highlighted cancer as a growing priority for women’s health and for health system sustainability. Dr Prebo Barango, lead for the Cervical Cancer Elimination Initiative, Dr Meghan Doherty, consultant for palliative care, and Santiago Milan, lead for the WHO Global Platform for Access to Childhood Cancer Medicine, presented WHO’s integrated approach to cancer control.
Palliative care is treatment and support that aims to improve quality of life for people with serious illness by managing pain and other symptoms.
The discussion underlined the need for sustained political commitment and domestic investment to address noncommunicable diseases.
Parliamentarians shared national experiences showing the social and economic impacts of cancer on families and caregivers, reinforcing the importance of improving health literacy, reducing stigma and delivering people-centred care.
The meeting also addressed the state of global multilateralism.
Dr Jeremy Farrar, assistant director-general for health promotion, disease prevention and care, outlined how WHO has restructured to enhance efficiency, impact and capacity to support countries.
He reaffirmed WHO’s commitment to more systematic engagement with parliaments, recognising their role in shaping health policy, legislation and budgets.
The exchange concluded with a call for continued collaboration, including through partnerships with the Konrad-Adenauer-Stiftung and the UNITE Parliamentarians Network for Global Health, ahead of the UNITE Global Summit 2026 on 6–7 March in Manila, the Philippines.
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