MOSCOW, November 17, Nadezhda Bekhova. Space tourism is gradually developing, orbital hotels are being designed, and stationary bases on the Moon are just around the corner. The question arises about possible pregnancies in conditions of weightlessness and increased radiation. To assess the risks for offspring conceived outside of Earth, scientists are conducting experiments on satellites and the ISS.
Honeymoon in orbit
In 2001, billionaire Dennis Tito, a former engineer at NASA, became the world's first space tourist. He spent seven days on the ISS. And recently I booked tickets with an open date (when the start is unknown) with SpaceX for a flight around the Moon – together with my wife. The Starship class ship can accommodate nine passengers and four crew members. Separate cabins are available.
The American company Orbital Assembly Corporation designs orbital hotels. One is luxurious, for the richest, for 28 people. The second is simpler, for 440 guests. With artificial gravity (due to rotation) – less than the earth's, as on the Moon or Mars.
Under the NASA program, several companies are developing versions of the station to replace the ISS. And Voyager Space conceived a private space hotel – in partnership with Hilton. They offer to spend a honeymoon or a romantic weekend there.
“Space is no longer the domain of professional astronauts, and transportation is rapidly evolving, so we think sex will happen there within the next ten years,” writes David Cullen of Cranfield University, one of the authors of the preprint on the inevitability of conception among space tourists.
It’s time to widely discuss “unregulated human conception” outside the Earth, scientists say. It is important to understand how this will affect pregnancy, whether there are high risks of abnormal fetal development and ectopic pregnancy.
Intimate questions
Humanity lives in a gravity of 1 g, under the protection of the magnetosphere and atmosphere, which do not allow galactic rays and solar wind to pass through . In orbit there is weightlessness and increased background radiation. During interplanetary travel, the ionizing radiation is even stronger.
There is very little information about the effect of extraterrestrial conditions on germ cells. In a recent review, experts from the UAE, Austria and South Africa found only 21 articles on this issue, of which 17 described experiments with animals on Earth, three on the ISS and one during the Space Shuttle program. According to these works, in microgravity and hard ionizing radiation, the quality of sperm in animals deteriorates and mutations occur. For men, the evidence is generally inconsistent. Perhaps due to different lengths of stay in space, sampling methods, and ages. Social and psychological factors should also not be neglected. We noticed that in space the level of sex hormones often decreases, which affects spermatogenesis.
Female astronauts typically suppress their periods during orbital missions using contraception and delay having children until after their careers. On average, this is 38 years, so it is often necessary to resort to artificial insemination. And childbirth, as a rule, is normal, American researchers note in a review in Nature.
The embryos returned to Earth
No mammal has ever become pregnant in orbit or given birth there. Experiments have shown that invertebrates, amphibians and fish can give birth to healthy offspring in orbit. Experiments with more highly organized species were carried out only on Earth, simulating weightlessness.
And these experiments were unsuccessful. But at the end of October it was reported that they managed to grow healthy mouse embryos on the ISS.
Frozen embryos were sent into orbit in August 2021. For them, Japanese scientists have developed a special incubator and thawing system. The fact is that the biomaterial is stored at a temperature of minus 95 degrees Celsius. Only a qualified biologist can handle defrosting and subsequent cultivation. For astronauts, the tools and protocols were completely redone.
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The Japanese have prepared eight incubators. Each contains 90 frozen embryos at the stage of two blastomeres. Half were thawed on the ISS and cultured for four days in zero gravity, the rest underwent the same procedure, but with artificial gravity of 1 g created by rotation. Then everything was put in the refrigerator and returned to Earth – a month later.
The embryos developed into normal blastocysts without noticeable DNA damage. However, significantly fewer survived compared to what was observed on Earth: 17-19 percent versus 82 percent. This is not enough to produce offspring using IVF. Scientists intend to continue their experiments and create a device for fertilizing a female mouse in space with grown embryos.
As for radiation, its destructive effect on organisms has been well studied. However, experiments on Earth cannot fully reproduce the complex conditions in space. Therefore, Chinese researchers sent the biomaterial in an incubator to the SJ-10 satellite and returned it a few days later in a descent capsule.
During the flight, the embryos developed noticeably more slowly, and their quality also suffered. In addition, serious damage was found in the DNA, including epigenetic abnormalities in the form of extra methyl groups. So long-term exposure to even small doses of radiation is clearly dangerous for offspring.