Fig. 1.
Graphic representation of ovarian function and menstrual activity in relation to menopause. Fig. 1A – For women who experience natural menopause, ovarian function, and menstrual activity decline gradually in a synchronized fashion (gradual shading of bars). Fig. 1B – Women who undergo hysterectomy with one or both ovaries conserved experience an abrupt cessation of menses at the time of the surgery (solid bar) but a gradual decline in ovarian function (gradual shading of bar). These women experience a lag time between hysterectomy and cessation of ovarian function that may last 10 or more years and may be difficult to measure correctly in the clinical setting. *In this figure, we are assuming that the removal of the uterus or of one ovary have no consequences on the remaining ovarian function (one or two conserved ovaries). In fact, removal of the uterus or of one ovary may lead to an earlier cessation of ovarian function by approximately 4 years (Farquhar et al., 2005; Rocca et al., 2007; Phung et al., 2010). Fig. 1C – Women who undergo bilateral oophorectomy with or without hysterectomy experience an abrupt cessation of both ovarian function and menstrual activity at the time of surgery (solid bars).