Ovulation

Moment at which a ripe egg cell is released from 1 of the ovaries. Ovulation occurs about 14 days before the next menstruation begins. It is the only time in the cycle when a sperm cell can fertilize an egg cell. An egg cell lives for about 24 hours. Because sperm cells can live up to 5 days, sexual intercourse in the days before ovulation can lead to a pregnancy.