👶 Reproduction in space: an intriguing experiment...

It seems paradoxical: embryos formed in microgravity initially show increased vigor, but then encounter growth problems. This discovery raises questions about the possibility of reproduction during future prolonged space missions.

Researchers at the University of Adelaide in Australia simulated the absence of Earth's gravity. They used a device called a clinostat, which rotates samples on two axes to create a sensation of weightlessness. In this setup, mammalian sperm, including human, showed a reduced ability to navigate towards an egg, with about 30% less success compared to normal conditions.


The team then observed the fate of embryos formed under these conditions. After a short period, these early embryos, called blastocysts, displayed greater vigor than those conceived under normal gravity. This initial advantage is likely explained by natural selection, where only the most capable sperm reach the egg in microgravity.

However, this promising momentum does not last. With prolonged exposure to the absence of gravity, the quality of these embryos deteriorates. They then begin to accumulate a developmental delay compared to their terrestrial counterparts. Scientists attribute this decline to disruptions caused by microgravity on cellular processes occurring during the first embryonic divisions.


This work, published in Communications Biology, adds an important piece to our knowledge about reproduction in space. It raises practical questions for space colony projects or tourist stays in orbit. If reproduction proves problematic in microgravity, maintaining human populations away from Earth would represent a major obstacle.

The team now plans to study whether reduced gravity, such as that on the Moon or Mars, could mitigate these effects. Meanwhile, the discovery of the initial improvement in embryo quality opens avenues for medically assisted reproduction technologies on Earth, particularly in the treatment of certain types of infertility.