Double stimulation in the same ovarian cycle (DuoStim) is an intriguing strategy to improve oocyte yield and the number of competent embryos in a short timeframe

Proper ovarian stimulation regimens are crucial for any patient undergoing in-vitro fertilization (IVF). However, maximizing the oocyte yield in advanced maternal age patients with poor or suboptimal response is still a challenge. In fact, no standard treatment has been outlined yet to manage these women. Across the last years, an improved efficiency of the IVF units via blastocyst culture, vitrification and reliable embryo selection approaches paved the way to the investigation of novel unconventional stimulation protocols, like double stimulation in a single ovarian cycle (DuoStim). DuoStim, by conjugating follicular phase stimulation (FPS) and luteal phase stimulation (LPS) in the same ovarian cycle, allows to maximize the number of oocytes obtained in a short timeframe, a precious outcome when we aim at shortening time to pregnancy. In this regard, LPS seems to contribute to conventional stimulation with more oocytes with a comparable competence as FPS, retrieved per ovarian cycle. Although any stimulation protocol which exploits anovulatory waves of follicular growth needs a thorough investigation, no evidence has been produced to question the safety of DuoStim, which to date represents the most intriguing strategy to treat poor prognosis in IVF.