Human animals have a simple, direct system: copulation and sperm delivery may lead to fertilization of an egg, if the timing is right. Once a sperm joins an egg, the resulting zygote gets implanted on ...

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. Lauren E.

The new embryo enters embryonic diapause until the new-born offspring leaves the pouch nine months later. Thus, when the embryonic diapause is included, females are continuously pregnant throughout ...

An underlying principle of female reproductive biology appears to have been overturned by a report from researchers at Massachusetts General Hospital (MGH). In an article in the March 11, 2004 issue ...

Optimal timing of reproduction is critical to ensure adequate conditions for raising young. However, factors influencing timing of reproduction may differ between sexes. Harsh seasonal environments ...

In mammals - including us humans - sperm are surprisingly picky about temperature, thriving best in conditions a few degrees cooler than normal body temperature. But, given that the female ...