Rising serum follicle-stimulating hormone levels is one of the earliest signs of human female reproductive aging. Whether or not elevated FSH remains a passive reflection of a diminishing ovarian follicle pool or actively contributes to declining female fertility with age has not been established. We therefore investigated female reproduction in mice expressing progressively rising serum levels of transgenic human FSH (Tg-FSH, 2.5-10 IU/L) independently of follicle depletion. We show that serum luteinizing hormone and estradiol levels and uterine size remained normal in Tg-FSH females, whereas ovarian weight and corpora lutea number were significantly increased up to 1.3 and 5-fold, respectively. Furthermore, the monotrophic FSH rise produced a striking biphasic effect on female fertility. Tg-FSH females less than 22 weeks old delivered increased litter sizes, then beyond 23 weeks litter sizes decreased rapidly culminating in premature infertility, despite continued ovary follicle development, increased ovulation and uterine embryo implantation sites, as well as normal serum levels of anti-mullerian hormone, a marker of ovarian follicle reserve. We found that rising circulating Tg-FSH produced premature infertility by increasing embryo-fetal resorption and parturition failure with age. Thus, our Tg-FSH mice present a novel paradigm to investigate selective contributions of elevated FSH to age-related female infertility, which revealed that rising FSH levels, in spite of no exhaustion of ovarian reserve, actively accelerates female reproductive aging primarily by post-implantation reduction of embryo-fetal survival.