It's commonly thought that sperm "race" to the egg, with the winner fertilizing it. But is this really the case?

While the causes are varied and range from infections to hormonal imbalances, deformities during meiosis—a specialized cell division process that creates sperm and eggs—is a leading cause.

They are formed in a woman's body before birth and have to be on standby for decades to possibly be fertilized one day. But as they age, they accumulate more and more DNA damage. Until now, it has ...

A genetic mutation in mice affects cells required for sexual reproduction and holds clues about male infertility that could pave the way for new treatments and male contraceptives, a Rutgers ...

Those germ cells that enter meiosis become oocytes ... oocytes within the ovary are already much larger than sperm, and the future egg retains most of this volume as it passes through meiosis.

Meiosis is the generation of germ cells (eggs and sperm). In meiosis, DNA replication is followed by two division cycles: meiosis I, which segregates homologous chromosomes and meiosis II ...

A new way to measure male fertility has been discovered by researchers at the University of Waterloo, opening the door to the ...

Just because a sperm is a strong swimmer doesn't necessarily mean it has the right amount of DNA, Dr. Lisa Lee told Newsweek.