Q: What is capacitation?

A: Capacitation is an important part of fertility, and is partially responsible for the sperm entering the egg.

Capacitation is the change in the sperm head membrane that prepares it for fusion with the egg membrane. Sperm have to undergo capacitation in the female reproductive tract before they are able to fertilize the egg. Capacitation is facilitated by the cervical mucus, and it usually takes several hours after ejaculation before the sperm can fertilize the egg. Sperm that reach the egg within minutes after ejaculation did not have enough time to undergo capacitation, and are less likely to be able to fertilize the egg.