Vitrification of oocytes produces high pregnancy rates when carried out in fertile women.

To determine the efficiency of our vitrification technique when applied in young fertile women. Clinical research and application. In vitro fertilization center. Twenty-one women were recruited from the navy community with 19 patients finishing the study. 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. Survival, fertilization, and cleavage rate. Pregnancy and implantation rate. 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. 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.

Kim TJ ，Laufer LR ，Hong SW 《-》

Delivery rate using cryopreserved oocytes is comparable to conventional in vitro fertilization using fresh oocytes: potential fertility preservation for female cancer patients.

To explore the use of oocyte cryopreservation as a fertility-conserving option. Cancer treatments administered during the reproductive and adolescent years can result in sterility. Previous fertility preservation efforts focused on embryo rather than oocyte storage because the latter was deemed inefficient. Recently, several large reports of healthy births resulting from the transfer of embryos derived from frozen/thawed oocytes have been published. We sought to establish an oocyte cryopreservation program at our center. Twenty-three oocyte cryopreservation cycles were performed. Collected oocytes were cryopreserved by either the slow or the vitrification method. Approximately 1-4 months later, a programmed cycle of thawing/warming, fertilization with intracytoplasmic sperm injection, and ET was performed; cycle and pregnancy outcomes were assessed. University-based fertility center. Twenty-two infertile women. Oocyte cryopreservation. Oocyte survival, embryo development, pregnancy outcomes. Oocyte survival, 2-pronuclei fertilization, and blastocyst formation rates were 92%, 79%, and 43%, respectively. Fourteen women became pregnant; one miscarried; 10 have delivered 13 viable infants, and three pregnancies are ongoing for an ongoing/delivered pregnancy rate of 57%. This result was not statistically different from cycles performed consecutively in age-matched controls using fresh, nonfrozen autologous or donor oocytes during a similar time period. Oocyte cryopreservation appears to be a viable option for fertility preservation in some centers.

Grifo JA ，Noyes N 《-》

High survival rate of metaphase II human oocytes after first polar body biopsy and vitrification: determining the effect of previtrification conditions.

Keskintepe L ，Agca Y ，Sher G ，Keskintepe M ，Maassarani G ... -  《-》

Impact of oocyte cryopreservation on embryo development.

To verify whether the morphologic evaluation of zygotes and embryos derived from thawed oocytes could provide some relevant information regarding their developmental performance. Fertilization, zygote, and embryo morphology from sibling fresh and frozen oocytes was compared. Reproductive Medicine Unit, Società Italiana Studi Medicina della Riproduzione, Bologna, Italy. Two hundred thirty-four patients underwent intracytoplasmic sperm injection cycles from which 1,101 spare metaphase II oocytes were cryopreserved. Subsequently, 256 thawing cycles were performed, and 997 oocytes were thawed. Intracytoplasmic sperm injection was performed on both fresh and frozen oocytes. Fertilization rates, pronuclear zygote morphology, and embryo cleavage rates. Thawed oocytes had lower chances of being fertilized and developing into top-quality zygotes and regularly cleaving embryos when compared with sibling fresh oocytes irrespective of female age. As a result, the percentage of transferred cycles was significantly lower in frozen cycles compared with fresh cycles (79% and 93%, respectively); the proportion of transferred top-quality embryos followed the same trend. Reduced fertilization and cleavage rates in frozen cycles when compared with sibling fresh oocytes suggest that, even if surviving thawing, the process of slow freezing has a negative impact on the potential of further growth that is evident as early as the first cleavage divisions.

Magli MC ，Lappi M ，Ferraretti AP ，Capoti A ，Ruberti A ，Gianaroli L ... -  《-》

Fertilization, embryo development, and clinical outcome of immature oocytes from stimulated intracytoplasmic sperm injection cycles.

Shu Y ，Gebhardt J ，Watt J ，Lyon J ，Dasig D ，Behr B ... -  《-》