Sperm that sit around in the body for a week or more start to develop abnormalities that make them less effective at head-banging their way into the egg.
Spermā, kas no ķermeņa netiek izvadīta vismaz nedēļu, sāk veidoties novirzes, kas padara to mazāk efektīvu,  kad ar galvu jāieurbjas olšūnā.