China has begun the world's first space experiment on human artificial embryos, with samples now aboard its space station and the study progressing smoothly, scientists announced Wednesday. Delivered ...

In a lab in Japan, scientists transformed cells from the tails of male mice into eggs. They fertilized the eggs with ordinary mouse sperm and implanted them in surrogate mouse moms. The experiment was ...

Over the past four decades, sperm counts among men worldwide have dropped by more than 50 percent, according to a 2022 meta-analysis published in Human Reproduction Update. The decline is accelerating ...