Background: Our aim was to examine whether women who had a low number of retrieved oocytes at their first IVF attempt reach the menopausal transition and/or the natural menopause earlier than women of similar ages with a high number of retrieved oocytes.
Methods: We conducted a retrospective cohort study among women in The Netherlands who received IVF treatment between 1983 and 1995. For the present study, we selected all cohort members who had a regular menstrual cycle at the time of the first visit to the gynaecologist (n = 4601). After a median follow-up of 5.5 years, 3871 (84%) women still had a regular menstrual cycle pattern, 547 (12%) women had entered the menopausal transition (i.e. no menses for 3-11 months, use of HRT or irregular menstrual cycles) and 27 (1%) women had reached natural menopause. We examined whether the quantity and the quality of the retrieved oocytes were related to an early menopausal transition and early menopause. The live birth rate per embryo transfer was used as indicative of the quality of the oocytes.
Results: The age-adjusted odds ratio (OR) for having entered the menopausal transition/natural menopause for women with a poor response (0-3 oocytes) at their first IVF attempt was 3.1 [95% confidence interval (CI) 2.4-3.8] compared with women with a normal response (>3 oocytes). Women who were stimulated with gonadotrophins during IVF treatment but did not undergo an IVF puncture because of an anticipated poor response (cancelled IVF cycle) had an age-adjusted OR of 3.2 (95% CI 2.3-4.3). There was no significant difference in the odds of reaching the menopausal transition/natural menopause, after adjustment for age and the number or retrieved oocytes, between women who did and did not have a live birth following their first embryo transfer (OR = 1.3; 95% CI 0.95-1.7).
Conclusions: These results indicate that a low remaining quantity of oocytes, as reflected by a low number of retrieved oocytes at first IVF treatment, is an important predictor of the risk of an early menopausal transition/natural menopause. The quality of the oocytes did not affect the risk of an early menopausal transition/natural menopause once the number of retrieved oocytes had been taken into account. Our findings support the concept that the number of remaining follicles in the ovaries is one of the main aspects of reproductive ageing.