Repronews #66: Can facilitating fertility reduce the gender wage gap?
Skepticism on artificial wombs | Japanese perspectives on PGT-M | Biggest countries in 2100 | Dalton Conley on sociogenomics | WaPo on longevity research | Fast-growing EU biotech
Welcome to the latest issue of Repronews! Highlights from this week’s edition:
Repro/genetics
Ruxandra Teslo on how changing educational/career structures and extending fertility can reduce the gender wage gap
A case for skepticism towards artificial wombs
How cancer patients’ perspectives changed Japanese people’s views on monogenic embryo screening
Population Policies & Trends
Visual Capitalist infographic: What will be the most populous countries in 2100?
Genetic Studies
Dalton Conley’s book on “sociogenomics” details the complex and often mutually reinforcing interactions between genetics and environment
Further Learning
The Washington Post reports on research on fighting aging by “reprogramming our genes”
Report on European biotech’s fast growing economic impact
Repro/genetics
Extending women’s fertility: How to fight the gender wage gap effectively (Ruxandra Teslo)
Ruxandra Teslo, a genomics PhD student at Cambridge’s Sanger Institute, writes on the challenges of women’s 30s often being the prime years for both career advancement and declining fertility, forcing a trade-off.
Studies show that the gender wage gap is largely due to career interruptions from childbirth and child-rearing. While men are spending more time with their children than ever before, women still tend to invest more time in childcare—something many enjoy but that also impacts career trajectories.
In “greedy careers” that demand long hours and uninterrupted commitment—like law, academia, and executive roles—this trade-off is particularly stark. Among business school graduates, women’s work hours decline over time, leading to earnings plateaus and fewer leadership roles.
Katalin Karikó, a scientist behind mRNA vaccine breakthroughs, credits affordable childcare in Hungary for allowing her to balance work and family. She argues society should address issues like childcare access and fertility constraints.
Teslo argues for tackling the biological and institutional misalignment of career progression and fertility. Education and career timelines should be restructured, such as encouraging earlier high school graduation, 3-year instead of 4-year BA degrees, majoring in law or medicine upfront, and faster career entry.
Since one’s 30s seem to be a natural sweet spot for professional growth, she says the best approach may be scientific innovation that expands reproductive options. Much like how contraception reshaped gender dynamics in the 20th century, fertility-extending technologies could revolutionize work-life balance in the 21st.
“Don’t count on artificial wombs” (Boom)
“Boom,” a pronatalist blogger, is skeptical about the potential of artificial wombs for end-to-end reproduction.
Artificial wombs now nearing human trials are not attempting to replicate pregnancy’s complex chemical processes and host a baby from conception to birth.
Rather, artificial wombs like the EXTrauterine Environment for Neonatal Development (EXTEND) aim to provide a safe place for premature babies to continue growing and prepare for the outside world.
In 2017, EXTEND successfully kept eight premature lambs alive for four weeks. Currently, human babies born before 24 weeks have a less than 50% chance of survival and artificial wombs to save the lives of these babies are urgently needed.
Human pregnancy is something of a black box and regulatory barriers make it hard for research to change that.
The “14 day rule,” a guideline adopted in many jurisdictions, including the Britain, India, the U.S., Canada and Japan, means embryos can only be cultured for research for 14 days. This limits research on the viability of artificial wombs.
This restriction may be loosened in the coming years. Britain’s fertility regulator (the HFEA) has recently recommended that this period be doubled to 28 days.
Boom concludes: “Though a world in which end-to-end artificial wombs exist and are perhaps even routinely used by ordinary people may lie in our future, we are not on the brink of developing this technology. But the birth rate challenge is happening today. People are having fewer children than they want right now and we are experiencing all the negative social and economic effects of that. … [T]he focus for policymakers should be on alleviating barriers to research where there is a strong ethical case for doing so, and on improving the access of ordinary people to conventional reproductive technology like IVF.”

Japanese people’s views on monogenic screening following patient testimony on eye and breast cancers (EJHG)
Despite countries expanding access to preimplantation genetic testing for monogenic disorders (PGT-M), Japan remains restrictive, approving only 17 conditions under the stringent criteria of the Japanese Society of Obstetrics and Gynecology (JSOG).
The researchers conducted a survey of 78 participants of a “Discussion about PGT-M with the Stakeholders” workshop in Hiroshima. The workshop facilitated dialogue among stakeholders, including patients, healthcare professionals, and ethicists, on the ethical and regulatory challenges of PGT-M.
The survey assessed participants’ perceptions before and after patient testimonies. A clinical geneticist explained the medical criteria for PGT-M and treatment options. Subsequently, individuals with hereditary cancer—including patients with retinoblastoma (a form of eye cancer that may lead to loss of vision or require eye removal) and BRCA2 (breast cancer) mutations—shared their lived experiences. This juxtaposition of medical information and personal narratives allowed participants to reflect on how “individual and familial lived experiences,” a crucial core dimension, influence perceptions of seriousness.
Before hearing patient testimonies, 66% of respondents said they would consider PGT-M if faced with hereditary cancer to not pass on the condition. 89% believed that patients should be informed about PGT-M at the time of diagnosis.

Perspectives shifted notably after hearing patient stories. The proportion of participants who viewed PGT-M primarily as a public health tool aimed at reducing societal burden significantly decreased, leading to a shift in emphasis towards individual reproductive autonomy.
Favorable attitudes toward marriage, pregnancy, and family planning with PGT-M rose from 54% pre-testimony to 71% post-testimony.
One patient recounted her experience of living with retinoblastoma and raising a child affected by the condition. Her PGT-M request was repeatedly denied under the rationale that the disease was “treatable.” Approval was granted only after extensive advocacy and increased societal awareness.
Participants expressed concerns about unclear eligibility criteria for PGT-M. The absence of standardized protocols for discussing PGT-M at diagnosis was seen as a significant gap compared to the West. The process of determining what qualifies as “serious” often lacks transparency.
Japan’s eugenic history has led to a cautious approach to adopting reproductive technologies like PGT-M. Disability advocacy groups have warned that expanding PGT-M access could perpetuate ableist attitudes. The authors write: “While such concerns are valid, they can sometimes overshadow patient autonomy… Balancing disability rights with reproductive choice remains a nuanced challenge.”
The authors stress that the changes in participant perceptions following patient testimonies “underscore the importance of incorporating diverse experiences into the evaluation of seriousness.”
More on repro/genetics:
Video: Whole genome sequencing 100,000 infants at birth—Implementing the UK’s Generation Study (PET)
“Genetic and reproductive strategies to prevent mitochondrial diseases” (Human Reproduction Update)
China’s BGI Genomics secures $130 million genetic testing contract for Saudi hospitals, providing whole genome sequencing, hereditary cancer screening, and preimplantation genetic testing (EurekAlert!)
Bryan Cwik, “Germline gene editing may never have any clinical utility” (American Journal of Bioethics)
Population Policies & Trends
Genetic Studies
“How nature and nurture shape a kid’s reading ability” (TIME)
Dalton Conley, Professor of Sociology at Princeton University and author of The Social Genome: The New Science of Nature and Nurture, discusses the role of genetics and environment in high school student’s reading ability, including SAT scores.
50 years of studies by psychologists on twins raised apart, adoptees, and half-siblings find that on average human traits are about half genetic and half environmental.
Height is about 80% genetic in developed countries. Personality traits are about 20% heritable and educational attainment 40%. Reading ability as measured by verbal test scores is highly heritable: over 80% by age 18.
Conley stressed that framing things in terms of nature vs. nurture is incorrect because genetics and environment interact in complex ways. This is being explored in the new field of sociogenomics.
He writes: “Scientists have long known that nature and nurture mutually reinforce each other. But what’s new here—in the past decade, when the genomics revolution has brought oodles of data to human scientists—is that we can now study exactly how the genes for, say, reading ability, are distributed across society and how they work their magic by creating or evoking environmental conditions and responses.”
For example, kids with a genetic tendency towards high verbal ability may beg their parents for more bedtime stories, thus reshaping their environment in a way which leads to greater verbal skills.
Conley writes: “It’s a cycle: genes create tendencies, which shape experiences, which reinforce those same genetic tendencies. This cycle starts very early. A study that Asta Breinholt and I conducted showed that parents unknowingly invest more time and resources in kids who show early academic promise. This means that much of what we think of as environmental is partly genes in action. …And the effects can snowball—small genetic advantages may turn into big differences over time, thanks to the way the environment reacts.”
Conley stresses that paradoxically “that also means that genes are not destiny.” We can “act on environments for those with advantageous or disadvantageous genes,” for example by making sure that people with a high genetic risk of addiction is not prescribed opioids for pain management. “[I]f we gain an understanding of someone’s genetic propensities, we may be able to adjust the environment in the way that most benefits them.”
He writes: “Over time, these genetic tendencies get reinforced by the environments we shape for ourselves. The curious kid seeks out books and interesting conversations, further sharpening their mind. The risk-averse person builds a life with stability and routine. As Joyce Carol Oates once said: ‘I don’t change; I become more myself.’”
Oates’ insight is visible in data for traits like intelligence. The genetic component becomes more predictive as people age into adulthood: at age 5 intelligence is 45% heritable, by 35 it is 80%. Verbal ability’s heritability increases from 48% at age 5 to 70% at the age to take the SAT. A similar pattern holds for political views.
Conley concludes: “It’s no longer about whether nature or nurture ‘wins’—because they’re not actually in competition. Instead, genetics and environment work in a dynamic loop, each shaping the other in constant, invisible, and powerful ways that ripple across our lives.”
More on genetic studies:
Jonathan Meddings, “The truth about intelligence: How genetics shape it — but don’t define it” (Medium)
Further Learning
“Can reprogramming our genes make us young again?” (Washington Post)
Scientists have made significant progress in longevity research, particularly through cellular reprogramming, a technique reverses aging at the cellular level.
A 2016 experiment at the Salk Institute showed that introducing four specific genes into mice with progeria (accelerated aging) extended their lifespan by 30%, sparking intense interest from tech billionaires and venture capitalists.
This approach has since been tested on various species, raising hopes that human trials may be on the horizon.
The key to this breakthrough lies in the Yamanaka factors, a set of genes discovered in 2006 by Nobel Prize-winning scientist Shinya Yamanaka. These factors remove molecular markers on DNA, known as methyl groups, which play a crucial role in aging. By stripping away these marks, cells can regain a more youthful state, potentially reversing age-related decline.
Cellular reprogramming has serious risks, including the formation of teratomas—abnormal growths where cells transform unpredictably, sometimes growing teeth or bone in the wrong locations.
A Harvard University study in 2020 showed that using a modified approach on mice with optic nerve damage restored vision without causing tumors. The biotech company Life Biosciences is preparing to seek FDA approval for the first human trial, which would target optic nerve strokes using this refined technique.
Longevity research continues to expand, with well-funded companies like Altos Labs receiving $3 billion in seed funding for research. While true life extension may still be far off, researchers believe that cellular reprogramming could at least slow aging and improve health in later life, redefining aging and human lifespan.

Fast-growing biotech sector boosted EU GDP by €75 billion in 2022 (EuropaBio)
EuropaBio, the pan-European biotech association, has commissioned a study on the biotech industry’s economic footprint in the European Union.
Gross value added (GVA) from biotech reached €38.1 billion in 2022, almost double from 2008. Healthcare biotechnology is the dominant contributor, but industrial biotechnology is the fastest growing with a growth rate of 5.3%, EU economy’s average growth.
Biotech total economic contribution, including indirect and spillover effects on GDP, was estimated at €75.16 billion.
Biotech is one of the most economically productive industries, generating €160,000 GVA per person employed in 2022. This is 2.85 times higher than EU average. EU biotech’s trade surplus increased sevenfold between 2008 and 2022.
More on human nature, evolution, and biotech:
Lewis O’brien, “Human Equivalents of the Peacock’s Tail: How mutual mate choice shaped human evolution” (Steve Stewart-Williams)
Geneticist Maarten Larmuseau’s research suggests around 1% of children in Europe over the past 500 years may have been born to false paternity (cuckoldry), not the 10% often cited (Science)
“Lab-grown meat, dairy, sugar and other cell-based foods set to become available to UK consumers by 2027” (BBC/GLP)
“European Union takes giant leap forward toward embracing technologically-enhanced agriculture, advances de-regulation of gene edited crops” (GLP)
“Long-term studies provide unique insights into evolution” (Nature)
Disclaimer: We cannot fact-check the linked-to stories and studies, nor do the views expressed necessarily reflect our own.