A case of failed oocyte maturation in vivo and in vitro

Objective: To study a couple for whom all oocytes failed to mature during three attempts at IVF/ICSI treatment. Our aims were (a) to promote oocyte maturation in vitro and (b) to identify the stage of maturation arrest. Design: Case report. Setting: Infertility treatment center with academic research links. Patient(s): Couple with unexplained infertility. Intervention(s): Exogenous gonadotropin stimulation culminating in the retrieval of right oocyte-cumulus complexes that were exposed to gonadotropins for 24 hours in vitro. Main Outcome Measure(s): Observation of oocyte cumulus complexes, measurements of oocyte diameter, oocyte chromatin staining with Hoechst 33258, Result(s): The cumulus complexes varied in appearance and expanded in vitro, but yielded immature oocytes. Germinal vesicle breakdown occurred in all oocytes;and chromatin was consistent with arrest at entry into M-phase. The oocytes were of a size normally competent to mature. Conclusion(s): Infertility in this couple was attributed to the failure of oocytes to enter M-phase. This was not overcome by exposure to gonadotropins in vitro nor associated with incompetence due to small oocyte size. (Fertil Steril(R) 1999;71.567-70. (C) 1999 by American Society for Reproductive Medicine.)