The heritability of menopausal age is estimated to range from 30-85%, indicating a significant genetic component in this complex trait in which multiple genes may be involved.
Menopause is the time in a woman's life when her menstrual cycles cease and her body undergoes changes that will no longer allow her to become pregnant. This is a natural event that generally occurs between the ages of 40 and 60, and is most common between the ages of 45 and 50. If the last menstrual cycle occurs before the age of 40, it is considered premature.
The first thing that happens is that menstrual periods begin to change, and may occur more or less frequently. This situation can last from one to three years. Menopause is complete when there has been no period for a year, which is called postmenopause.
Population studies indicate that factors that may affect the age at which women have their final menstrual cycle are: smoking, age at menarche (first menstrual cycle), parity or total number of pregnancies, use of oral contraceptives, body mass index, ethnicity, socio-cultural factors, diet, physical exercise and family history.