Cytogenetic evaluation of human oocytes that failed to complete meiotic maturation in vitro

OBJECTIVE: To determine the cause of infertility in a couple whose oocytes failed to mature in two consecutive fertility treatments. DESIGN: Case report. SETTING: University-based IVF program. PATIENT(S): A 32-year-old woman with unexplained infertility. INTERVENTION(S): Cytogenetic evaluation of oocytes that failed to reach meiotic metaphase II stage of maturation. MAIN OUTCOME MEASURE(S): Observation of oocyte maturity and chromosome composition after fixing and staining with Orcein stain. RESULT(S): Cytogenetic analysis revealed that the oocytes had successfully resumed meiosis. Germinal vesicle breakdown was also indicated, and chromosomes were at metaphase II stage of development. However, meiotic reduction of those chromosomes failed. CONCLUSION(S): Infertility in this couple seems to be attributed to the failure of the chromosomes to complete the reduction phase of metaphase II of meiosis.