Search

Objective: To report a birth of a healthy boy after long-term cryopreservation of oocytes by vitrification. Design: Clinical application. Setting: IVF Center. Patient: A 17 year-old female with secondary pulmonary hypertension caused by transposition of great vessels visited our center in 2002, and she wished oocytes cryopreservation to avoid possible sterility after the following category X medication treatment. Intervention(s): Vitrified oocytes on Electron Microscope (EM) grids were warmed after 5 years of storage. Surviving MII oocytes were microinjected for fertilization and two embryos were transferred into a gestational carrier day 5 after microinjection. Main Outcome Measure(s): Survival, fertilization, cleavage, clinical pregnancy and delivery. Result(s): Eleven out of fourteen oocytes (78.6%) survived warming. Eight Metaphase II (MII) oocytes and 3 in vitro matured oocytes were microinjected; all 11 oocytes (100%) fertilized and 2 embryos were transferred on day 5. A healthy baby boy weighing 3,600 g was delivered at 38 weeks of gestation. Live-birth rates per warmed oocyte and per injected oocyte were 7.1% and 9.1% respectively. Conclusion(s): Cryopreservation after vitrification with EM grids maintained the developmental competence of oocytes after long-term storage and resulted in a successful live birth. [ABSTRACT FROM AUTHOR]

Objective: To determine the efficiency of our vitrification technique when applied in young fertile women. Design: Clinical research and application. Setting: In vitro fertilization center. Patient(s): Twenty-one women were recruited from the navy community with 19 patients finishing the study. Intervention(s): Vitrified oocytes with use of the electron microscopic grid method were warmed 6 months after vitrification. Surviving metaphase II oocytes were microinjected for fertilization, and clinical results were evaluated. Main Outcome Measure(s): Survival, fertilization, and cleavage rate. Pregnancy and implantation rate. Result(s): Three hundred ninety-five oocytes were warmed, of which 320 oocytes (81.0%) survived. Two hundred eighty-five metaphase II oocytes were microinjected for fertilization; 206 of them (72.3%) fertilized, and 53 embryos were transferred to 19 patients (in 20 warming cycles). Twenty-four of 53 transferred embryos (45.3%) implanted as confirmed by ultrasound examination. Of the 20 transfers, 16 resulted in clinical pregnancy (80%), 3 miscarried (15%), and 13 (65%) went on to produce 20 live births, respectively. This is much higher in comparison with our previous data using supernumerary oocytes where the rates of implantation and pregnancy were 6% and 21%. Live-birth rates per warmed oocyte and per injected oocyte were 5.1% and 7.2%, respectively. Conclusion(s): High pregnancy and implantation rates were observed after 6 months of cryopreservation by vitrification when oocytes from fertile woman were used. Proper screening of candidates for oocyte cryopreservation is of crucial importance to assure a favorable pregnancy outcome. [Copyright &y& Elsevier]