Immature Sperm

An immature sperm is a “younger” sperm cell that lacks the characteristic features and functions of mature sperm. An immature sperm is immobile, so it cannot swim through the fallopian tube to reach the egg and does not have the ability to break down the wall of the egg to fertilize it (acrosome reaction). For this reason, men with a relatively high proportion of immature sperm can have low fertility.

An immature sperm is also called a spermatid or sperm precursor cell.