Objective  To investigate the change of uterine size in ovarian aging in women living in a Beijing community.

  Methods  A total of 418 healthy women aged 30 to 68 years who could be staged by STRAW+10 staging system were recruited from a Beijing community and prospectively followed up for 5 years. Menstrual dairy was recorded daily by every woman during the research. Transvaginal ultrasonography was performed for measurement of uterine size at baseline and each year during the 5 years. Serum estradiol (E₂) was tested as well.

  Results  At baseline, various diameters and volume of uterus began to shrink significantly since the early post-menopausal stage+1a and shrank further at stage+1c (P < 0.05), while not changed much at late post-meno-pausal stage. The thickness of endometrium decreased from stage+1a (P < 0.05) and showed no significant change after that (P>0.05). E₂ in menopausal transition and the first 2 years after menopause had a large variation that no significant difference was found comparing with reproductive stage (P>0.05). E₂ level decreased significantly at stage+1c(P < 0.05) and kept at a low level at late postmenopausal stage, with no statistically significant difference compared with stage+1c (P>0.05). For women still at the same STRAW+10 stages after 5-year's follow-up, there was only decline in some diameters at early and late postmenopausal stages and no obvious change in endometrial thickness. E₂ level only decreased in the late postmenopausal stage(P < 0.01). For women with stage progress after 5-year's follow-up, each line diameter and volume of the uterus changed significantly during transition to early postmenopausal stage +1a/+1b, or from menopausal transition stage to ensuing stages. Change in endometrial thickness was only found in those transformed since menopausal transition stage. E₂ level changed mainly after menopausal transition stage. Uterine fibroids increased significantly during the transition from the reproductive stage to the menopausal transition stage (P < 0.01) and began to shrink after menopause but with no statistically significant difference(P>0.05). The decline in uterine volume in women with uterine fibroid was mainly observed at early postmenopausal stage, with no obvious change afterwards.

  Conclusions  Uterine size, endometrial thickness, and E₂ level do not change in synchronization. Uterine size shrinks during a rather long time since menopause, endometrial thickness begins to reduce mainly in the early stage after menopause. E₂ in menopausal transition and the first 2 years after menopause has a big variation which does not decrease obviously until 2 years after menopause.