Outlook: Roles of FSH and LH during the follicular phase: insight into natural cycle IVF.

A mounting interest in natural cycle IVF has challenged the medical community to better understand the mechanisms controlling the follicular phase and ovulation in particular, in an effort to optimize this procedure and its outcome. For practical reasons, the advancement of the follicular phase in the menstrual cycle is commonly timed according to the onset of last menses. However, this precludes knowing when the follicular phase truly begins and hampers the possibility of optimizing timing of late follicular-phase events, notably, the triggering of ovulation.