Progress in understanding human ovarian folliculogenesis and its implications in assisted reproduction

Abstract

Purpose To highlight recent progress in understanding the pattern of follicular wave emergence of human menstrual cycle, providing a brief overview of the new options for human ovarian stimulation and oocyte retrieval by making full use of follicular physiological waves of the patients either with normal or abnormal ovarian reserve. Methods Literature review and editorial commentary. Results There has been increasing evidence to suggest that multiple (two or three) antral follicular waves are recruited during human menstrual cycle. The treatment regimens designed based on the theory of follicular waves, to promote increased success with assisted reproduction technology (ART) and fertility preservation have been reported. These new options for human ovarian stimulation and oocyte retrieval by making full use of follicular waves of the patients either with normal or abnormal ovarian reserve lead to new thinking about the standard protocols in ART and challenge the traditional theory that a single wave of antral follicles grows only during the follicular phase of the menstrual cycle. Conclusions The understanding of human ovarian folliculogenesis may have profound implications in ART and fertility preservation. Further studies are needed to evaluate the optimal regimens in ART based on the theory of follicular waves and to identify non-invasive markers for predicting the outcome and the potential utilities of follicles obtained from anovulatory follicular waves in ART.

Luteal phase ovarian stimulation following oocyte retrieval: is it helpful for poor responders?

“…The traditional concept of folliculogenesis supports the recruitment of various antral follicles in each ovary from the “late luteal phase” of the preceding menstrual cycle to the following follicular phase [ 12 ]. Interestingly, there is increasing evidence to indicate that multiple waves of antral follicles develop during the same woman’s menstrual cycle challenging the concept of single recruitment episode during the follicular phase [ 12 , 14 ].…”

Immature oocyte retrieval and in vitro oocyte maturation at different phases of the menstrual cycle in women with cancer who require urgent gonadotoxic treatment

“…However, luteal phase IVM retrieval has been performed to avoid delaying cancer treatment (3)(4)(5)(6). The concept of multiple major follicle recruitment waves during a normal menstrual cycle supports this practice (7)(8)(9). We evaluated the feasibility and the efficacy of IVM treatment when oocyte retrieval was performed in early follicular, late follicular, or luteal phase in women with cancer who required urgent gonadotoxic treatment.…”

Fertility with early reduction of ovarian reserve: the last straw that breaks the Camel’s back

“…This has opened up a new horizon of opportunities to utilize ovarian stimulation in luteal phase following oocyte retrieval with follicular phase stimulation in the same cycle [108]. Typically, a luteal phase stimulation starts 2–7 days after oocyte retrieval in the same cycle.…”