Humanity’s greatest challenge in becoming a multi-planet species may not be building bigger rockets or landing astronauts on Mars. Instead, it could come down to the question: Can humans safely conceive, carry pregnancies, and raise healthy children off Earth?
A new review published in Frontiers in Space Technologies argues that the answer to this question remains unclear. Drawing on decades of research on animal reproduction in space alongside emerging advances in artificial intelligence, biotechnology, synthetic biology, and cybernetic systems, the researchers suggest that future generations born off Earth may require technologies far beyond today’s medical capabilities.
In the most speculative sections of the paper, researchers even envision a scenario in which reproduction itself acts as a tool for helping humans gradually adapt to life in space.
Rather than presenting new experiments, the paper synthesizes existing evidence while outlining possible technological pathways that could someday enable permanent human settlements on the Moon, Mars, or even deeper into the solar system.
The central message is that surviving in space is only the first hurdle. Establishing self-sustaining civilizations will ultimately depend on whether human reproduction can succeed under conditions of microgravity, radiation, isolation, and other environmental stresses that evolution never prepared us to face.
“It is proposed that prenatal and early postnatal developmental stages may constitute critical biological windows for facilitating long-term adaptation to space,” researchers write. “Such interactions could ultimately transform reproduction and early development into active drivers of human evolution, contributing to the emergence of biologically distinct populations progressively adapted to diverse space environments.”
Despite more than six decades of human spaceflight, no human has ever conceived or carried a pregnancy in space. Therefore, science has little direct evidence about what would happen if astronauts attempted to start families off Earth. Nearly everything researchers know comes from studies involving animals ranging from sea urchins and fish to frogs, birds, mice, and rats.
The results are encouraging in some respects but troubling in others.
Several non-mammalian species have successfully reproduced in orbit. Medaka fish, for example, became the first vertebrates to reproduce in space, with fertilization rates comparable to those seen on Earth. Yet, even when reproduction occurs successfully, researchers have documented developmental abnormalities in some species, suggesting that space environments can slightly modify embryonic development.
Rodent studies paint an even more complicated picture. Fertilization is not impossible under microgravity, but early embryonic development frequently suffers. Experiments have shown reduced blastocyst formation, slower embryo development, lower live birth rates, and changes in gene expression. Other studies have linked space radiation to DNA damage, genomic instability, and developmental defects affecting the nervous system.
At the same time, some findings show surprising resilience. Mouse embryos cultured aboard the International Space Station have developed into apparently normal blastocysts under certain conditions. In contrast, freeze-dried mouse sperm stored in orbit for months later produced healthy offspring after returning to Earth.
These mixed findings suggest that reproduction may be biologically possible, but far from routine, under space conditions.
In their review, researchers also examined growing evidence that spaceflight affects male and female reproductive health even before conception occurs.
Microgravity and radiation appear capable of disrupting sperm production, reducing testosterone levels, altering ovarian function, impairing egg maturation, and interfering with hormone regulation.
Some studies suggest sperm can still swim under simulated microgravity, but lose their capability to navigate effectively toward an egg. Others report that radiation accelerates the depletion of ovarian follicles and increases DNA damage in reproductive cells.
More concerning is the possibility that some biological changes could be passed to future generations through epigenetic mechanisms. Experiments involving mice have suggested that spaceflight may alter gene regulation in sperm and influence gene expression in offspring, although the long-term significance is still unknown.
For women, pregnancy itself could present an even greater challenge. On Earth, pregnancy requires profound cardiovascular changes that help deliver oxygen and nutrients to a growing fetus. Microgravity, however, causes fluid redistribution, muscle loss, reduced blood volume, bone demineralization, and changes in cardiovascular function that could interfere with placental development and fetal growth. Radiation exposure, oxidative stress, circadian disruption, and limited medical support would only add to those risks.
Researchers argue that simply shielding astronauts from radiation may not be enough. Gravity itself appears to function as a biological signal that influences everything from cell organization to tissue development. That realization carries renewed interest in artificial gravity as a potential solution.
Instead of depending solely on habitats built on the Moon or Mars, future space settlements could include rotating structures that generate centrifugal force to recreate Earth-like gravity.
Such habitats have appeared in science fiction for decades, but researchers suggest they may ultimately become essential for healthy conception, pregnancy, childhood development, and multigenerational life off Earth.
Researchers propose dedicated orbital research platforms where scientists could systematically study reproduction under lunar, Martian, or custom-designed gravity levels before humans attempt permanent settlements.
Artificial intelligence also features prominently in the researchers’ vision of the future. They propose AI-powered “digital twins” capable of integrating biological, physiological, and environmental data to simulate how embryos, pregnancies, and developing children might respond to different gravitational and radiation environments. These computer simulations could help researchers examine scenarios that would be difficult, or ethically impossible, to test directly in humans.
Perhaps the paper’s most futuristic proposal is something the researchers call Synthetic Reproductive Adaptive Enhancement Technology, or SRAET. This speculative concept envisions highly automated reproductive systems combining artificial wombs, advanced reproductive biotechnology, biosensors, AI-assisted monitoring, and predictive developmental modeling into a closed-loop environment capable of supporting conception through birth under carefully controlled conditions.
The framework explores the controversial possibility that future advances in gene editing and synthetic biology could one day help humans adapt biologically to off-world environments.
Researchers emphasize that such ideas are still speculative and acknowledge the enormous ethical, biological, and safety concerns surrounding germline modification, off-target mutations, and multigenerational consequences. Rather than advocating immediate implementation, they present these possibilities as conceptual pathways that justify careful scientific and ethical discussion.
For fans of science fiction, many of these concepts may sound remarkably familiar. Yet, researchers attempt to ground their arguments in existing developmental biology, reproductive medicine, aerospace engineering, and space medicine while clearly distinguishing current evidence from future speculation.
In the end, researchers suggest that the future of human space travel may depend less on propulsion systems than on understanding how life develops under entirely new environmental conditions. If humanity hopes to establish permanent settlements off Earth, science will first need to ensure that future generations are able to begin life safely under alien skies.
“Ultimately, the greatest challenge of human expansion beyond Earth may not be transporting humans into space, but understanding how life itself can develop, adapt, and evolve under space conditions,” researchers write. “In this sense, SRAET would not merely support reproduction beyond Earth; it would represent a developmental biotechnology through which humanity may begin to actively participate in shaping its own evolutionary future.”
Study: Ferraz M, Moeharram L. “Past, present and future of human reproduction and development in space.” Frontiers in Space Technologies. 2026.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com
Naked mole-rats have long puzzled biologists with their striking eusocial structure, where most adults remain reproductively suppressed while a queen controls the colony’s future. Now, a new study identifies a chemical “queen odour” that links social status to endocrine control, revealing a mammalian analogue to insect queen pheromones.
The molecule, termed IPM, is enriched by the queen and acts as the key mediator of reproductive suppression in non-breeding females. When IPM is present, circulating prolactin rises while progesterone is suppressed, locking the colony into a stable reproductive hierarchy characterized by reduced conflict and maintained group cohesion.
Crucially, the team connects this behavioural outcome to the brain. Using multiple approaches—including non-invasive functional ultrasound imaging (fUSI)—they show that IPM provokes strong activation of olfactory neurons and central neural circuits. This provides a neural substrate for how a chemical cue can trigger colony-wide physiological change, rather than relying on social learning or passive association.
The experiments also clarify sensory routing. Ablating olfaction abolishes aggression initiation and lowers prolactin levels, directly tying IPM detection to reproductive suppression. While the findings are consistent with sensing through the main olfactory epithelium, the authors note that the vomeronasal system may still contribute.
Queen removal normally destabilizes colonies, leading to aggression, reproductive competition, prolactin decline, and, in extreme cases, mortality. Yet when IPM is added to queenless bedding, the colony remains stable for months. During this period, fecal progesterone metabolite levels stay low, indicating sustained ovarian quiescence alongside elevated prolactin.
The study also addresses a longstanding paradox: transferring soiled bedding and urine from parent colonies fails to maintain suppression in isolated individuals. The authors propose that IPM’s chemistry helps explain this discrepancy. As a long-chain fatty acid ester with low volatility, IPM may persist within the colony environment but fail to travel effectively over distance or survive transfer pathways that preferentially carry other chemicals.
Comparative work extends beyond naked mole-rats. IPM is detected in breeding females of four additional Fukomys species. Although reproductive suppression mechanisms may differ across species, the presence of a similar queen-linked odorant suggests convergent chemical strategies for managing reproductive skew in eusocial mammals.
Overall, the research reframes reproduction control as a chemosensory-to-endocrine pathway: IPM activates olfactory–hypothalamic signalling, elevating prolactin and inhibiting GnRH release. This “social hormone” model offers a new principle for social evolution—chemical cues can synchronize behaviour and physiology at the scale of an entire mammal colony.
Subject of Research: Reproductive suppression and social hierarchy in eusocial mammals (naked mole-rats and related Fukomys species)
Article Title: A queen odour mediates reproductive suppression in a eusocial mammal
Article References:
Khallaf, M.A., Hart, D.W., Luo, W. et al. A queen odour mediates reproductive suppression in a eusocial mammal.
Nature (2026). https://doi.org/10.1038/s41586-026-10772-5
Image Credits: AI Generated
DOI: https://doi.org/10.1038/s41586-026-10772-5
Keywords: IPM; queen odour; reproductive suppression; prolactin; GnRH; olfaction; eusociality; functional ultrasound imaging; Fukomys
In the rapidly advancing field of assisted reproductive technologies (ART), subtle biochemical cues during treatment cycles can have profound and lasting impacts on offspring health. A groundbreaking study by Jiang, Wei, Liu, and colleagues, set to appear in Nature Communications in 2026, reveals intricate links between human chorionic gonadotropin (hCG) exposure on the trigger day of ART protocols and enduring epigenetic modifications that influence neurodevelopmental trajectories in children conceived via these methods. This research shines a spotlight on the complex interplay between hormonal interventions during ART and the epigenetic landscape shaping long-term neurodevelopmental outcomes.
At the core of this investigation lies hCG, a glycoprotein hormone traditionally recognized for its critical role in early pregnancy maintenance. It is clinically administered as a trigger to induce final oocyte maturation and subsequent ovulation in ART cycles. Despite its widespread use, the broader biological consequences of hCG administration timing and dosage, particularly regarding the epigenome of resulting embryos and offspring, remain poorly understood. Jiang and colleagues address this knowledge gap by systematically evaluating how hCG exposure on trigger day affects DNA methylation patterns—a key epigenetic mechanism regulating gene expression—in offspring conceived via ART.
Utilizing a large cohort of ART offspring and sophisticated epigenomic profiling techniques, the researchers uncovered that variations in trigger-day hCG levels corresponded to distinct DNA methylation signatures detectable in peripheral tissues of the children years post-birth. These methylation changes were not random but localized to genes with established roles in neurodevelopment and synaptic function. Notably, altered methylation was observed in loci involved in neuronal proliferation, differentiation, and synaptic plasticity, processes fundamental to cognitive development and neurological health.
The implications of these findings are considerable given the rising prevalence of ART-conceived individuals globally. Epigenetic modifications such as DNA methylation are dynamic yet heritable through cell division, and perturbations during critical windows of embryonic development can have cascading effects on gene regulation. Jiang et al.’s data suggest that the timing and hormonal milieu created by hCG administration on trigger day may inadvertently shape the epigenetic program of the embryo with consequences extending into postnatal brain development.
To unravel the potential neurodevelopmental consequences, the team correlated their epigenetic data with standardized neuropsychological assessments performed on the ART offspring. They reported significant associations between specific methylation patterns and measures of cognitive function, executive processing, and social behavior, domains frequently implicated in neurodevelopmental disorders. This links the biochemical intervention in ART directly to behavioral phenotypes observed in the children, underscoring the functional relevance of epigenetic imprinting driven by hCG exposure.
Mechanistically, the study posits that hCG triggers a cascade of intracellular signaling events including modulation of DNA methyltransferase (DNMT) activity and chromatin remodelers during oocyte maturation and early embryo development. These processes may alter the establishment or maintenance of methylation marks at neurodevelopmentally critical genes. Interestingly, variations in the hCG dose and timing created distinct epigenomic landscapes, emphasizing the fine balance required in ART hormone protocols to avoid unintended epigenetic dysregulation.
This research not only advances understanding of ART-associated neurodevelopmental risks but also offers actionable insights for clinical practice. Optimizing hCG administration parameters could mitigate adverse epigenetic and developmental outcomes, enhancing the safety profile of ART. The notion that a single hormonal manipulation at a specific time point can induce persistent epigenomic and neurodevelopmental alterations demands a reevaluation of ART protocols incorporating epigenetic endpoints.
The findings may also have broader implications beyond ART, revealing fundamental principles of how transient hormonal milieus during early development can imprint long-lasting changes on gene regulation and phenotype. This could inform developmental biology, neuroepigenetics, and endocrine research, potentially identifying biomarkers predictive of neurodevelopmental risk across diverse prenatal exposures.
Furthermore, the study leverages cutting-edge epigenomic technologies such as whole-genome bisulfite sequencing and single-cell methylation analysis, coupled with rigorous neurobehavioral phenotyping in a longitudinal cohort framework. This integrative, multi-omics approach sets a new standard for assessing the safety and long-term effects of reproductive interventions, blending molecular precision with clinical relevance.
Ethically, these insights prompt a dialogue about the need for comprehensive monitoring of ART offspring, integrating epigenetic screening and neurodevelopmental surveillance to detect and potentially intervene in early deviations. The epigenetic alterations detected by Jiang et al. are reversible in principle, raising the prospect of targeted epigenetic therapies or nutritional interventions to restore typical developmental trajectories.
Moreover, the study encourages further exploration into paternal contributions and environmental factors interacting with trigger-day hCG effects, recognizing that ART outcomes emerge from a complex interplay of genetics, epigenetics, and external exposures. Identifying modifiers of hCG-induced epigenetic programming could refine personalized ART approaches tailored to individual risk profiles.
Overall, this landmark research by Jiang and colleagues opens a new frontier in reproductive medicine, illustrating that the endocrinology of ART cycles extends beyond immediate gamete maturation to sculpt the epigenomic and neurodevelopmental fate of future generations. It reinforces the imperative for precision medicine in reproductive technologies and highlights the power of epigenetics in mediating early-life environmental influences on human development.
As ART continues to bring hope to millions struggling with infertility, understanding and controlling the subtle molecular ripples of treatment interventions like hCG administration becomes paramount. Jiang et al.’s study sets a vital precedent, demonstrating that optimizing hormone triggers is not merely a matter of improving pregnancy rates but safeguarding the neurological health and well-being of ART-conceived individuals throughout their lives.
Subject of Research: Human chorionic gonadotropin (hCG) effects on DNA methylation and neurodevelopment in offspring conceived via assisted reproductive technologies (ART).
Article Title: Trigger-day hCG effects on DNA methylation and neurodevelopment in ART offspring.
Article References:
Jiang, Y., Wei, X., Liu, X. et al. Trigger-day hCG effects on DNA methylation and neurodevelopment in ART offspring. Nat Commun (2026). https://doi.org/10.1038/s41467-026-74712-7
Image Credits: AI Generated
Fossils from some of the oldest-known animals on Earth, dating from 574 million years ago (Ediacaran period), suggest that cloning, not competition, dominated the Ediacaran seas, slowing evolution until environmental stress helped drive the rise of sexual reproduction and a burst of biodiversity.
The post Earth’s Earliest Animals May Have Thrived Too Easily to Evolve appeared first on Sci.News: Breaking Science News.
Outside experts found that two studies cited in a federal case on medication abortion had serious design problems and that their authors had undisclosed conflicts of interest
© Erin Hooley/Chicago Tribune/Tribune News Service via Getty Images
Login