Is reproduction in space possible? Scientists investigate

Humankind's aspirations to become an interplanetary species necessitate understanding how reproduction might occur in microgravity conditions. Questions around the feasibility of pregnancy, its maintenance, and birthing in space pose significant challenges for future exploration. Current research on the International Space Station (ISS) is illuminating these issues.

Presently, we lack conclusive knowledge about whether reproduction - from conception to birth - is safe for parents and their progeny in microgravity. Nevertheless, recent experiments hint at optimistic possibilities. Evidence reveals that mouse embryos can develop in space without any adverse effects.

In August 2021, a scientific study involved dispatching fertilized mouse cells to the ISS. These cells, frozen for transit, were subsequently thawed aboard the ISS and kept at body temperature in a designated location. Over four days, the zygotes were allowed to develop into the blastocyst stage, a cell group that ultimately forms the fetus and placenta.

Comparative samples were retained on Earth, while another sample, sent to the ISS, was situated in a centrifuge to simulate artificial gravity. The study revealed that, in all three settings, embryonic development was consistent.

The researchers wrote, "The embryos cultured under microgravity conditions developed into blastocysts with normal cell numbers, inner cell mass, trophectoderm, and gene expression profiles similar to those cultured under artificial-1 g control on the International Space Station and ground-1 g control". This suggests that gravity doesn't significantly influence the formation of blastocysts and the early development of mammalian embryos, as published in iScience.

The experiment results are promising. Previous studies, using mice, also indicate that space flights neither affect mouse fertility nor increase offspring mortality of those conceived post-return to Earth.

Notwithstanding, it's worth noting that the blastocyst stage represents an early phase of pregnancy in humans, occurring roughly three weeks post-fertilization. The highest risk of complications arises much later, an area future research will undoubtedly explore. It's essential to recognize that human physiological responses may differ from those of mice.

The study's researchers also highlight another aspect. Astronauts aboard the ISS spend a significant portion of their day exercising to reduce gravity's impact on bones and muscles. The question remains whether an expecting astronaut, despite her activity level, can transmit these benefits to her fetus. The potential effects of this scenario are yet to be understood.