We’re Nowhere Near Ready to Make Babies in Space, Experts Warn

If humanity truly hopes to colonize the solar system, it must overcome a challenge arguably greater than any technological hurdle: human reproduction beyond Earth. The idea may sound like science fiction, but a group of experts says figuring out how to protect astronauts’ reproductive health—and even make babies in space—is a very real and urgent issue.

In a report published Tuesday in the journal Reproductive BioMedicine Online, these experts argue that now is the time to build a comprehensive framework governing reproductive health and research in space. As both the distance and duration of human spaceflight missions extend, the hazards of space pose increasing risks to fertility, gamete health, and embryonic development, they say.

“Although we do not advocate reproduction in space at present, it is essential to prepare for fertility risks 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 prospect, but proactive planning is needed to address the biological, ethical, and health hazards that may arise.”

The reproductive hazards of spaceflight

Because the human body evolved here on Earth, it is fine-tuned to operate within the environmental conditions of our home planet. Space is therefore completely incompatible with our biology and physiology.

Radiation and microgravity are two of the greatest hazards to astronauts’ reproductive health. “Space radiation can damage DNA, disrupt gamete formation, and raise cancer risk, while microgravity interferes with hormonal regulation, gamete quality, and embryonic development,” Palmer explained.

Other threats inherent to 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 added. Being in space can also disrupt astronauts’ circadian rhythms—leading to hormonal imbalances and reduced fertility—and induce psychological stress that might impair reproductive function.

“Over the long term, prolonged exposure to these conditions may cause cumulative reproductive damage and heritable risks, including epigenetic changes that alter gene expression and potentially affect fertility and the health of future offspring,” Palmer said.

Charting a safe, ethical path forward

Before scientists can address these hazards, they need to fill critical 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 that was provided by women who flew on NASA’s Space Shuttle missions indicated that subsequent pregnancy rates and complications were largely unaffected, limited data has so far been reported from men and women who flew on longer missions. As such, there is a need for new evidence “to guide diagnostic, preventative, and therapeutic strategies in extraterrestrial environments,” the report’s authors write.

Future studies should aim to improve our understanding of how space hazards impact various stages of the reproductive process, according to Palmer and his colleagues. This new knowledge will help scientists develop more effective strategies to protect astronauts’ reproductive health, such as radiation shielding, medical countermeasures, and fertility-preservation methods.

“Advancing assisted reproductive technologies through AI, automation, and non-invasive tools will be key for safe use in space, alongside establishing clear ethical guidelines that prioritize informed consent, transparency, gender equity, and the protection of future offspring,” Palmer said.

One can’t overstate the importance of these ethical guidelines as humanity expands its reach beyond Earth and progresses toward in-space reproduction. But just to be clear, scientists will not be sending pregnant humans to space for research or any other purpose. Rather, they will rely on simulated environments and non-human models to study the reproductive risks of spaceflight, Palmer explained.

Still, “entering this new research frontier makes it essential to act now by establishing an international framework and a collective industry ethics review board,” he said. This will not only ensure that in-space reproductive research is conducted safely, responsibly, and transparently, but also safeguard humanity’s future as we work to establish a sustained presence beyond Earth.

Related: Humans will never colonize Mars