Programming the onset of ovarian stimulation: from early follicular phase start to oral contraceptive pill, to luteal phase E2, Duostim, and random start oral contraceptive protocols.

Ovarian stimulation has been the single most efficient measure ever taken in assisted reproductive technology for improving outcomes by harvesting multiple oocytes and ultimately, embryos. Today, ovarian stimulation protocols consist of administrating exogenous gonadotropins to override the natural mechanisms that control the ovulatory quota to one in humans. For practicality issues, there have been numerous attempts to control, or "program," when ovarian stimulation is initiated to improve functionality and in turn efficacy for assisted reproductive technology programs. The different options for controlling the onset of ovarian stimulation currently available are discussed here, as well as the novel possibility of using progestins for blocking premature ovulation.