Biological Clock

A woman's biological clock is the relationship between the age of the person and her fertility. The fertile period of a woman starts with the attainment of menarche. Fertility increases as a woman ages, peaks around 20-25 years of age and then gradually starts to decline.

A drop in fertility is typically seen around 35 years with a complete cessation of fertility occurring after the woman reaches menopause. The biological clock plays an important role in determining a woman's chances of conceiving successfully and the need for fertility treatment.