Pregnancy resulting from transfer of repeat vitrified blastocysts produced by in-vitro matured oocytes in patient with polycystic ovary syndrome

This report describes a live birth produced from repeat vitrification and thawing of blastocysts derived from in-vitro matured (IVM) oocytes in a woman with polycystic ovarian syndrome. Immature oocyte retrieval was performed on day 12 of her induced menstrual cycle. The patient was administered 10,000 IU of human chorionic gonadotrophin s.c. 36 h before immature oocyte retrieval. A total of 47 immature oocytes were collected. Following IVM of these immature oocytes, 76.6% (36/47) become mature (at metaphase II stage). Thirty oocytes (30/36, 86.1%) were normally fertilized following insemination by intracytoplasmic sperm injection. The fertilized zygotes (two-pronuclear stage) were co-cultured with cumulus cells in YS medium supplemented with 10% human follicular fluid. On day 5 after insemination, three blastocysts were transferred. Unfortunately, fresh embryo transfer did not result in pregnancy. The remaining 10 embryos developed to the expanded blastocyst stage. These remaining blastocysts were vitrified with electron microscope grids following artificial shrinkage. Three months later, three blastocysts were thawed due to a clinical error. Consequently, the embryos were re-vitrified. After a week, the three blastocysts were warmed again. Two of them developed to hatched blastocysts. Following transfer, a full-term pregnancy resulted in the delivery of healthy twins.