Scientists have reported it for decades: Overpopulation can impair reproduction. Crowded chickens lay fewer eggs. Crowded ...

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.

A new article in Ecological and Evolutionary Physiology examines how the immune system and reproduction interact in female mammals, especially during pregnancy, from mating to birth. Subscribe to our ...