BIRTH AFTER CRYOPRESERVATION OF IMMATURE OOCYTES WITH SUBSEQUENT IN-VITRO MATURATION

Objective: To establish the clinical feasibility of using cryostored g erminal vesicle oocytes for IVF and ET. Design: Case report. Setting: Private infertility clinic. Patient(s): A 28-year-old woman with tubal infertility undergoing IVF therapy.Intervention(s): Oocytes collected after ovarian stimulation were frozen without insemination or were in seminated, fertilized, and frozen as cleavage stage embryos. No fresh oocyte or embryo transfer was undertaken. All oocytes were thawed, and those that survived were used for IVF-ET. Main Outcome Measure(s): Oo cyte cryosurvival, in vitro maturation, fertilization, embryo developm ent, and pregnancy outcome. Result(s): None of 16 mature oocytes survi ved thawing; however, three of 13 germinal vesicle oocytes survived. A fter 30 hours in vitro maturation two oocytes had matured and underwen t intracytoplasmic sperm injection with the partner's sperm. Both fert ilized normally and were transferred to the patient. The woman deliver ed an apparently healthy female infant at 40 weeks. Conclusion(s): Thi s case report proves the feasibility if not the efficiency of using im mature oocytes for cryostorage, coupling both cryopreservation and in vitro maturation. (Fertil Steril(R) 1998;70:578-9. (C) 1998 by America n Society for Reproductive Medicine.).