A novel system for in vitro maturation of human oocytes

Objective: To compare in vitro maturation of cumulus-free oocytes in glucos e-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 a llocated to culture with P1 or TC199. Metaphase II oocytes were fixed for i mmunofluorescence analysis or fluorescence in situ hybridization at 24 or 4 8 hours (or both). Media were compared by performing conditional logistic r egression analysis that controlled for egg-specific factors. Main Outcome Measure(s): Proportion of mature oocytes and appearance of nor mal spindle-chromosome cytoarchitecture. Reproductive Medicine, Result(s): At 24 hours, more P1 oocytes than TC199 oocytes reached metaphas e 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. Met aphase 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 ge rminal vesicle stage at 0 hour, those at metaphase I at 0 hour were more li kely 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 America n Society for Reproductive Medicine.).