Successful Clinical Outcome After a Modified Protocol of Rescue In Vitro Maturation of Oocytes: A Case Series Study

<i>In vitro</i> maturation (IVM) of oocytes represents an assisted reproductive technique with minimal or no ovarian stimulation application, rendering it beneficial for specific groups of patients facing infertility. IVM is based on the collection of immature cumulus-oocyte complexes (COCs) from antral follicles, subsequently cultured <i>in vitro</i> until they reach the metaphase II (MII) stage. Once maturation is accomplished, IVM oocytes are fertilized according to standard procedures. A variation of IVM is the "Rescue-IVM" protocol, which involves the maturation of immature COCs collected after a conventional <i>in vitro</i> fertilization (IVF) cycle, with a standard controlled ovarian stimulation protocol and <i>in vivo</i> human chorionic gonadotropin (hCG) maturation triggering. These immature COCs are cultured <i>in vitro</i> from the germinal vesicle (GV) on retrieval day (day zero) to the MII stage on the maturation check day (day one), prior to intracytoplasmic sperm injection (ICSI). In this study, we report five cases of patients who underwent an assisted reproductive technology (ART) cycle combined with modified Rescue-IVM, resulting in successful pregnancies. These cases offer high hope for patients with no synchronized follicles during ovarian stimulation to achieve a pregnancy, even when the fertilization occurs up to 28 hours post oocyte retrieval.