Video of a new mathematical model that predicts that mammalian sperm cells have two distinct swimming modes. This prediction opens new questions about potential connections between sperm cells’ motor ...

Researchers at Newcastle University in England report they have coaxed the first human sperm cells from embryonic stem cells, in a remarkable demonstration of how quickly the field of stem-cell ...

Research into how a father’s choices — such as diet, exercise, stress, nicotine use — may transfer traits to his children has ...

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: ...

Sperm are male reproductive (sex) cells. The word "sperm" can refer to spermatozoon (singular) or spermatozoa (plural). Sperm are tiny cells with an oval-shaped body and a long tail. They measure just ...

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 ...