title: [Cryopreservation of human oocytes in the pronuclear stage with an automated "open system"].
abstract: In the period from June 1990 to February 1993, 718 excess pronucleated oocytes from 185 cycles were cryopreserved by using the "open freezing system" in our IVF-programme at the Department of Gynaecology and Hospital of the University of Bonn. 1.5 mol propanediol and 0.1 mol sucrose were used as a cryoprotectant. During this time 287, pronuclear oocytes were thawed; of these 245 survived the freezing process and were classified as intact. The survival rate in this study was 85.4%, though if only one intact pronuclear oocyte was transferred, no pregnancy could be achieved, whereas if two or three pronuclear oocytes were transferred, seven to ten pregnancies resulted, respectively (23.3% and 23.8% pregnancy rates). Eight healthy children have been born to date from four other ongoing pregnancies, one of them is a twin pregnancy.
authors.affiliation: Klinik für Frauenheilkunde und Geburtshilfe, Medizinische Universität zu Lübeck.
authors.forename: S
authors.initials: S
authors.lastname: al-Hasani
authors.forename: K
authors.initials: K
authors.lastname: Diedrich
authors.forename: O
authors.initials: O
authors.lastname: Bauer
authors.forename: M
authors.initials: M
authors.lastname: Hartje
authors.forename: D
authors.initials: D
authors.lastname: Krebs
mesh_terms: D002470:Cell Survival / Q000502:physiology; D015925:Cryopreservation / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D005307:Fertilization in Vitro / Q000295:instrumentation*; D006801:Humans; D007231:Infant, Newborn; D007247:Infertility, Female / Q000628:therapy*; D009865:Oocytes / Q000637:transplantation*; D011247:Pregnancy; D017388:Zygote Intrafallopian Transfer / Q000295:instrumentation*