Vitrification versus slow freezing of oocytes: effects on morphologic appearance, meiotic spindle configuration, and DNA damage.

To assess possible effects on subcellular organization after cryopreservation, we compared vitrified and slowly frozen oocytes in terms of their post-warm/thaw morphology, meiotic spindle configuration, and DNA integrity. DNA integrity of cryopreserved oocytes was not altered after the procedures, but vitrification was more effective than slow cooling, as shown by higher survival rate and spindle assessment despite a higher misalignment between meiotic spindle and polar body.

Twins born after transplantation of ovarian cortical tissue and oocyte vitrification.

OBJECTIVE: To present a combination of ovarian tissue and oocyte cryopreservation as an effective strategy for achieving pregnancy in a breast cancer patient. DESIGN: Case report. SETTING: Tertiary care university-affiliated hospital, tissue bank, and infertility clinic. PATIENT(S): A 36-year-old patient diagnosed with atypical medullar breast cancer and negative for estrogen, P, and HER2 receptors underwent ovarian tissue cryopreservation before receiving chemotherapy and radiotherapy. INTERVENTION(S): Laparoscopic ovarian cortex extraction, ovarian tissue cryopreservation, ovarian tissue thawing and transplantation, controlled ovarian stimulation (COS), oocyte retrieval, vitrification and IVF, and embryo culture and replacement. MAIN OUTCOME MEASURE(S): Resumption of spontaneous ovarian function after transplantation, response to COS, oocyte vitrification, IVF, pregnancy, and delivery. RESULT(S): Menses occurred 63 days after transplantation. Sixteen mature oocytes were obtained in four COS procedures. All vitrified oocytes survived warming, and 77.7% were fertilized. Two day 3 embryos were replaced, and two healthy boys were born at 34 weeks. CONCLUSION(S): Ovarian tissue cryopreservation and grafting preserves fertility. Simultaneous oocyte vitrification increases the success of assisted reproductive technology in poor-prognosis patients and avoids the consequences of the short lifespan of the transplanted tissue.