Health and Medicine
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For all the talk about settling Mars, the Moon, or other extraterrestrial environments, it’s interesting that no one ever seems to mention the fact that reproduction in space has never been attempted. After all, we’re going to need to make a lot of alien babies if we want to thrive beyond Earth, so we’d better start learning a thing or two about cosmic loving.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.And that, in a nutshell, is the message delivered by a new report from a multidisciplinary group of scientists, including experts in reproductive health, aerospace medicine and bioethics. Just to be clear, the authors aren’t calling for any sexy space experiments, but simply highlight the alarming gaps in our knowledge regarding the risks associated with off-world reproduction.
“Despite over 65 years of human spaceflight activities, little is known of the impact of the space environment on the human reproductive systems during long-duration missions,” write the researchers. “Extended time in space poses potential hazards to the reproductive function of female and male astronauts, including exposure to cosmic radiation, altered gravity, psychological and physical stress, and disruption to circadian rhythm,” they explain.
Spermatogenesis, for instance, relies on rapid cell division – a process that is easily disrupted by radiation exposure. Experiments involving male mice have shown that spending one month aboard the International Space Station can alter DNA expression in the testes, although no comparable research has been conducted on human astronauts.
Likewise, we still don’t know how microgravity might interfere with reproduction, although there are reasons to believe it might cause problems. For example, post-fertilization processes like embryogenesis and implantation appear to rely on gravitational forces, suggesting that pregnancies in space may be at risk of complications.
Encouragingly, one study has shown that women who flew on NASA’s Space Shuttle did not experience elevated rates of pregnancy issues after returning to Earth. However, these female astronauts were all involved in short-term missions, and there’s currently no data regarding the reproductive risks associated with spending long periods of time in space, or traveling further than low-Earth orbit.
“Although short-term missions appear to have minimal impact on fertility, the long-term effects of radiation, microgravity, hormonal disruption, and epigenetic change remain unclear,” write the researchers. “As missions extend in duration and humanity moves towards establishing permanent off-world habitats, such as lunar bases or Mars expeditions, concerns about fertility and reproductive health are no longer hypothetical but pressing.”
The report authors therefore call for the creation of a comprehensive framework for examining the risks of reproduction in space, so that when the time does come to begin populating the cosmos, we’re ready.
“As human presence in space expands, reproductive health can no longer remain a policy blind spot,” said senior study author and NASA research scientist Dr Fathi Karouia in a statement. “International collaboration is urgently needed to close critical knowledge gaps and establish ethical guidelines that protect both professional and private astronauts – and ultimately safeguard humanity as we move toward a sustained presence beyond Earth.”
The study is published in the journal Reproductive BioMedicine Online.
