Simulated microgravity reportedly impairs sperm navigation, raising challenges for space reproduction

A post describing a University of Adelaide study says sperm from humans, mice and pigs largely retained swimming speed under simulated microgravity but struggled to navigate. Human sperm's success in a reproductive-tract-like maze fell about 40%; mouse fertilization success fell about 30% after four hours of exposure. Progesterone partly restored human sperm navigation, and the post suggests assisted reproduction or artificial gravity as possible approaches for space settlements.