Do men become less fertile with age?

Men also become less fertile with age, but their fertility decreases more slowly than in women and only begins to decline in later life. After the age of 45, we increasingly find chromosomal damage in sperm cells. This can lead to reduced fertility, to the eggs stopping developing before pregnancy occurs, or very early in pregnancy. We can detect such genetic errors with the Comet test, which examines the genetic content of each individual sperm cell.