Male and female reproductive systems allow human reproduction. Fertilisation occurs when a sperm and egg join to form an embryo. An embryo develops into an unborn baby in the uterus during pregnancy.

Modern humans may indeed have wiped out Neanderthals – but not through war or murder alone. A new study suggests that when the two species interbred, a slow-acting genetic incompatibility increased ...

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 ...