OBJECTIVE: To document the possibility to double-cryopreserve human metaphase II and pronuclear oocytes. DESIGN: Case report. SETTING: University-based IVF center. PATIENT(S): A couple with primary andrological infertility. INTERVENTION(S): Pronuclear stage oocytes derived after sperm injection into frozen-thawed metaphase II oocytes were cryopreserved again for later transfer. MAIN OUTCOME MEASURE(S): Post-thaw survival rates and pregnancy. RESULT(S): Five metaphase II oocytes survived the freeze-thaw procedure. Three of five oocytes presented with two pronuclei after sperm injection and were cryopreserved again. Post-thawing, all three oocytes developed into good quality embryos for transfer. A singleton pregnancy was achieved, resulting in the birth of a healthy girl. CONCLUSION(S): Double-cryopreservation of oocytes at metaphase II and at pronuclear stage is a treatment option in human-assisted reproduction.
OBJECTIVE: To document the possibility to double-cryopreserve human metaphase II and pronuclear oocytes. DESIGN: Case report. SETTING: University-based IVF center. PATIENT(S): A couple with primary andrological infertility. INTERVENTION(S): Pronuclear stage oocytes derived after sperm injection into frozen-thawed metaphase II oocytes were cryopreserved again for later transfer. MAIN OUTCOME MEASURE(S): Post-thaw survival rates and pregnancy. RESULT(S): Five metaphase II oocytes survived the freeze-thaw procedure. Three of five oocytes presented with two pronuclei after sperm injection and were cryopreserved again. Post-thawing, all three oocytes developed into good quality embryos for transfer. A singleton pregnancy was achieved, resulting in the birth of a healthy girl. CONCLUSION(S): Double-cryopreservation of oocytes at metaphase II and at pronuclear stage is a treatment option in human-assisted reproduction.