In a report published Tuesday in the online journal Reproductive Biomedicine, these experts argue that now is the time to create a comprehensive framework governing reproductive health and research in the space. They say that as both the distance and duration of human spaceflight missions increase, space hazards pose increasing risks to fertility, gamete health, and fetal development.
“Although we do not currently advocate reproduction in space, preparing for reproductive risks is essential as renewed interest in lunar missions and Mars exploration grows,” lead author Giles Palmer, a clinical embryologist and executive director of the International IVF Initiative, told Gizmodo in an email. “Reproduction in space remains a distant possibility, but active planning is needed to deal with the biological, ethical and health threats that may arise.”
Reproductive risks of space flight
Because the human body evolved here on Earth, it is well-adapted to function in the environmental conditions of our home planet. So space is completely incompatible with our biology and physiology.
Radiation and microgravity are the two biggest threats to astronauts’ reproductive health. “Space radiation can damage DNA, disrupt gamete formation and increase cancer risk, while microgravity interferes with hormonal regulation, gamete quality and embryo development,” Palmer explained.
Other hazards inherent in the space environment include toxic dust from lunar or Martian regolith, limited resources, and chemical or microbial contamination within enclosed spacecraft, all of which can harm maternal and fetal health, he said. Living in space can also disrupt astronauts’ circadian rhythms—causing hormonal imbalance and reduced fertility—and induce psychological stress that can impair reproductive function.
“Over the long term, chronic exposure to these conditions can lead to cumulative reproductive damage and hereditary risks, including epigenetic changes that alter gene expression and potentially affect the fertility and health of future offspring,” Palmer said.
Determining a safe, ethical path forward
Before scientists can address these threats, they need to fill significant knowledge gaps about them. For example, studies in animal models have shown that short-term radiation exposure disrupts menstrual cycles and increases cancer risk, but Palmer’s review found little reliable data from astronauts who returned from long-term space missions.
While data provided by women flying on NASA space shuttle missions indicated that subsequent pregnancy rates and complications were largely unaffected, limited data have been reported so far from men and women flying on longer missions. Thus, the report’s authors write, new evidence is needed “to guide diagnostic, preventive, and therapeutic strategies in extraterrestrial environments.”
According to Palmer and his colleagues, future studies should aim to improve our understanding of how space hazards affect different stages of the reproductive process. This new knowledge will help scientists develop more effective strategies to protect astronauts’ reproductive health, such as radiation shielding, medical countermeasures, and fertility-preserving methods.
“Advancing assisted reproductive technologies through AI, automation, and non-invasive devices will be critical to their safe use in space, as well as establishing clear ethical guidelines that prioritize informed consent, transparency, gender equity, and the safety of future offspring,” Palmer said.
One cannot overstate the importance of these ethical guidelines as humanity continues to expand its reach beyond Earth and move toward reproducing in space. But to be clear, scientists will not send pregnant humans into space for research or any other purpose. Instead, they will rely on simulated environments and non-human models to study the reproductive risks of space flight, Palmer explained.
Still, “entering this new research frontier makes it necessary to act by establishing an international framework and a collective industry ethics review board,” he said. This will not only ensure that reproductive research in space is conducted safely, responsibly and transparently, but will also safeguard the future of humanity as we work to establish a continued presence beyond Earth.
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