In the United States, an estimated 645,000 men ages 20 to 50 have azoospermia, a condition in which no sperm are present in their ejaculate. Now, scientists are testing a potential treatment: ...

Human sperm have long been a subject of fascination—not just for their role in fertilization, but for their remarkable ability to navigate through some of the most viscous environments in the body.

More than one-sixth of adults around the world experience infertility in their lifetime. There is a high unmet need not only for increased access to affordable, high-quality fertility care for those ...

Groundbreaking research shows that as men age, harmful genetic mutations in sperm become more common—not just from random chance, but because some are naturally favored. Advanced sequencing revealed ...

A man in his early 20s received a transplant of his own sperm-producing stem cells, which had been frozen since his childhood, in an attempt to regain fertility. Doctors are waiting to see if the ...