Smoking marijuana may harm a man's fertility, according to new research. But men who smoke pot may also have sperm that are faster swimmers.

New research clarifies the role of albumin in both fertilization and fighting infection.

Immigration has historically offset America's low fertility rate, but the recent dramatic drop in immigration threatens that trend.

Separating child-free adults (those who chose not to have children) from other types of nonparents reveals they're just as happy.

Separating child-free adults (those who chose not to have children) from other types of nonparents reveals they're just as happy.

Many embryos blacklisted by a test for IVF fertilization often develop into healthy babies. "This is going to revolutionize how IVF moves forward."

Researchers have used the gene editing tool CRISPR/Cas9 to make male mosquitoes infertile. When females mate with them, they're rendered infertile, too.

Rising fears over declining human sperm count among men in Western countries may be overblown, according to researchers at Harvard’s GenderSci Lab.

Our chemical environment appears responsible for an alarming plummet in sperm counts – in humans and in animals.