In women, there has been little evidence to indicate a sparing effect of oral contraceptive use on the age of menopause. One recent report indicates that women with a history of oral contraceptive use have lower cycle Day 3 FSH values than women with no prior history. Since this FSH value is believed to be predictive of the ovarian follicular reserve, these findings may suggest some influence of oral contraceptives on the rate of follicular recruitment. In this regard, it is important to note that we began P4 implant treatments relatively early and implemented them over a relatively long period in the reproductive life span of the female rat. Thus, variations in the age at which oral contraceptive use is initiated, and the consistency of such use, may make it difficult to determine significant effects of steroids on the rate of follicular loss in women. In addition, most oral contraceptives contain low amounts of estrogens. ventolin inhalers
In this regard, we have demonstrated that in female rats, cotreatment with E2 counteracts the protective effects of P4 implants on reproductive aging. Thus, the low amounts of estrogens in oral contraceptives may counteract potential protective effects of P4 on follicular loss. It is also not clear whether the progesterone derivatives used in contraceptives would have the same protective effects as P4 used in this study. Nevertheless, future studies of women who receive long-term treatments with progestogen implants (Norplant) for contraceptive purposes may provide more insight into the role of elevated P4 on follicular recruitment and the onset of menopause.