Human parthenogenetic blastocysts derived from noninseminated cryopreserved human oocytes

Objective: To report on the development of human parthenogenetic blastocysts and an in vitro attachment that was generated from noninseminated cryopreserved human oocytes for the first time. Design: Prospective study. Setting: Department of reproductive medicine in a medical institute in Buenos Aires, Argentina. Patient(s): Five healthy fertile donors. Intervention(s): Artificial activation of noninseminated cryopreserved human oocytes after thawing, parthenote culture, and their in vitro attachment. Main Outcome Measure(s): Survival rate, activation rate, cleavage rate, and blastocyst formation. Result(s): Thirty-six of 38 cryopreserved noninseminated oocytes survived after thawing (survival rate, 94.7%). Thirty-one of 36 oocytes showed one pronucleus (activation rate, 86.1%). Thirty of 31 cleaved (cleavage rate, 96.8%). Five of 30 showed cavitation (blastocyst rate, 16.7%). Conclusion(s): Noninseminated cryopreserved human oocytes showed a high survival rate after thawing. They responded very satisfactorily to artificial activation, which was followed by a high rate of parthenogenetic embryos, which can develop into blastocysts. In the future, these could be a new source for development of human parthe- nogenetic stem cells. (Fertil SterilÒ 2008;89:943–7. Ó2008 by American Society for Reproductive Medicine.)