Rescue In Vitro Maturation of a Germinal Vesicle Oocyte Leading to Pregnancy in a Case of Unexplained Infertility

Rescue in vitro maturation (rescue-IVM) refers to the post-retrieval culture of immature oocytes - typically at the germinal vesicle (GV) or metaphase I (MI) stage - under laboratory conditions, allowing them to complete maturation to metaphase II (MII) and become suitable for fertilization. This case report presents a successful pregnancy following rescue-IVM and preimplantation genetic testing for aneuploidy (PGT-A) in a 35-year-old woman with unexplained infertility and a history of ectopic pregnancy. Immature GV-stage oocytes retrieved during in vitro fertilization (IVF) were cultured using standard protocols, and several progressed to MII without pharmacologic stimulation. Following delayed intracytoplasmic sperm injection (ICSI), two euploid blastocysts were obtained, one of which led to a viable singleton pregnancy. This case underscores the clinical relevance of rescue-IVM in IVF cycles with high proportions of immature oocytes, particularly in patients with diminished ovarian reserve or tubal factor infertility. It highlights the importance of individualized assisted reproductive technology (ART) strategies, and the potential of advanced embryology techniques - such as time-lapse monitoring and optimized ICSI timing - to improve outcomes in poor-prognosis cases.