Microgravity Impairs Sperm Navigation in Study

Researchers at the University of Adelaide have discovered that microgravity significantly impairs sperm navigation, raising new challenges for human reproduction in space. The study, published on March 26 in the journal Communications Biology, tested sperm from humans, mice and pigs in simulated zero-gravity conditions and found reduced success in reaching targets mimicking the female reproductive tract.

The team, led by Dr. Nicole McPherson from the university's Robinson Research Institute, used a 3D clinostat device to replicate microgravity. This machine rotates samples continuously, randomizing gravitational cues and creating a state of effective weightlessness for the cells. Sperm samples were introduced into narrow chambers designed to simulate the reproductive tract, where they attempted to navigate toward an egg-like endpoint.

In normal Earth gravity, sperm oriented themselves effectively, but under simulated microgravity, far fewer completed the path successfully across all three species. "This is the first time we have been able to show that gravity is an important factor in sperm's ability to navigate through a channel like the reproductive tract," McPherson said. The...