Fertility is the ability of either a man or woman to conceive a child. It commences with puberty, rapidly reaches a peak, then slowly declines to the menopause in women and at a later age, the andropause in men.
Even if a woman is menstruating regularly at the age of 50, her fertility is greatly reduced due to the inability of eggs (ova) to be successfully released with each menstrual cycle. A woman’s fertility starts to reduce markedly from about 38 years of age and by 50 is down to 1% (i.e. a one in 100 chance of falling pregnant in a year with regular sex and no contraception).