Menopause
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
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.