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 ...

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 ...