Menopause
Menopause typically occurs between 49 and 52 years of age. The majority of women have their last period between the ages of 48 and 55. The average age of the last period in the United States is 51 years, in the United Kingdom is 52 years, in Ireland is 50 years and in Australia is 51 years. In India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. The menopausal transition or perimenopause leading up to menopause usually lasts 7 years (sometimes as long as 14 years).
Hysterectomy
The average onset age of menopause after hysterectomy with ovarian conservation is 3.7 years earlier than average. This has been suggested to be due to the disruption of blood supply to the ovaries after a hysterectomy or due to missing endocrine feedback of the uterus. The function of the remaining ovaries is significantly affected in about 40% of women, some of them even require hormone replacement treatment. Surprisingly, a similar and only slightly weaker effect has been observed for endometrial ablation which is often considered as an alternative to hysterectomy.