Men have nipples, mammary glands and the hormones required, but the ability for male lactation rarely turns on. Here’s why ...

Some animals have reproductive strategies so extreme that they can lead directly to their own death. In certain species, ...

(Pirotehnik/iStock/Getty Images Plus) Giving birth to more than the average number of children or having no children at all ...

When closely related species mate, their offspring sometimes survive but cannot reproduce. This pattern often affects males ...

Microglia (immune cells) and the RANK protein are essential for triggering puberty and maintaining fertility in the brain.

How many kids is too many, or too few, for your health? Science may finally have an answer, and it's not what you'd expect.

A new study shows that as humpback whale populations recover from past whaling, older males are gaining a major advantage in ...

There is something like less than one chance in 10 billion that this kind of thing could occur," said one expert.

Most people know only two things about the appendix: You don’t need it – and if it bursts, you need surgery fast. That basic ...

If you’re trying to conceive, timing may matter in more ways than previously thought. Researchers at the University of Manchester, Queen’s University in Ontario, Canada and Cryos International in ...

A study published in 'Nature' indicates that the number of children and the timing of having them are related to biological ...