Fertility is the natural capability of giving life. Both women and men have hormonal cycles which determine both when a woman can achieve pregnancy and when a man is most virile. The female cycle is approximately twenty-eight days long, but the male cycle is variable. Men can produce sperm at any time of the month, but their sperm quality reduces occasionally, which scientists guess is in relation to their internal cycle.
In men, Erectile Dysfunction increases with age, but fertility does not decline in men as significantly as it does in women, however, evidence suggests that increased male age is associated with a decline in semen volume, sperm mobility, and sperm morphology.
In women, age plays a specific role in fertility. Although women can become pregnant at any time during their menstrual cycle, peak fertility occurs during just a few days of the cycle, usually two days before and two days after the ovulation date. This fertile window varies from woman to woman, just as the ovulation date often varies from cycle to cycle for the same woman. The ovule is usually capable of being fertilized for up to 48 hours after it is released from the ovary. Sperm survive inside the uterus between 48 to 72 hours on average, with the maximum being 120 hours (5 days).