Ongoing twin pregnancy after vitrification of blastocysts produced by in-vitro matured oocytes retrieved from a woman with polycystic ovary syndrome

Abstract

This case report describes an ongoing pregnancy after cryopreservation of blastocysts produced by in-vitro matured oocytes retrieved from a woman with polycystic ovary syndrome (PCOS). Oocyte retrieval was performed on day 18. The patient was administered 10 000 IU of hCG s.c. 36 h prior to oocyte collection. A total of 61 immature oocytes was obtained. Following incubation for 24-72 h in the YS maturation medium supplemented with 30% follicular fluid (hFF), 1 IU/ml FSH, 10 IU/ml hCG and 10 ng/ml rhEGF, 65.6% (40/61) of the oocytes were at the metaphase II stage. Thirty-eight oocytes (38/40, 95.0%) were fertilized after ICSI with the patient's husband's sperm and the 2PN oocytes were co-cultured with cumulus cells in YS medium supplemented with 10% hFF. Four embryos were transferred into the uterus on day 4 following oocyte retrieval but this failed to result in pregnancy. Eight embryos were developed to expanded blastocyst stage. The blastocysts were vitrified on electron microscope grids. Two years after cryopreservation, four blastocysts were thawed, three re-expanded and these frozen-thawed blastocysts were transferred to the uterus. A viable twin pregnancy was confirmed by ultrasound scan.