A novel system for in vitro maturation of human oocytes

Objective: To compare in vitro maturation of cumulus-free oocytes in glucose-free medium (P1) and standard medium (TC199). Design: Prospective, cohort study. Setting: Assisted reproductive technology program. Patient(s): One hundred eight patients undergoing ICSI. Intervention(s): Germinal vesicle-stage or metaphase I-stage oocytes were allocated to culture with P1 or TC199. Metaphase II oocytes were fixed for immunofluorescence analysis or fluorescence in situ hybridization at 24 or 48 hours (or both). Media were compared by performing conditional logistic regression analysis that controlled for egg-specific factors. Main Outcome Measure(s): Proportion of mature oocytes and appearance of normal spindle-chromosome cytoarchitecture. Reproductive Medicine, Result(s): At 24 hours, more P1 oocytes than TC199 oocytes reached metaphase II (59.7% vs. 44.9%). At 48 hours, 71.7% of P1 oocytes and 61.0% of TC199 oocytes reached metaphase II, but this difference was not significant. Metaphase II oocytes in P1 were 34.3% more likely than those in TC199 to have a bipolar spindle with aligned chromosomes. Compared with oocytes at the germinal vesicle stage at 0 hour, those at metaphase I at 0 hour were more likely to progress to metaphase II (72.6% vs. 46.1% at 24 hours; 84.1% vs. 60.6% at 48 hours). Conclusion(s): P1 is superior to TC199 for in vitro maturation of granulosa-free human oocytes. (Fertil Steril(R) 2001;75:1185-93. (C) 2001 by American Society for Reproductive Medicine.).