title: Cryopreservation of oocytes and embryos.
abstract: In humans, embryo cryopreservation is now a widespread routine procedure, both reliable and flexible. It can successfully be applied to excess embryos, arising from in vitro fertilization, at any developmental stage. The role of gonadotropin-releasing hormone analogues in embryo freezing has given rise to much controversy, whereas in oocyte donation, systematic embryo cryopreservation reduces the efficacy of the whole procedure. New ultrarapid techniques led for the first time to viable pregnancies. Whereas technical goals are being achieved, social and legal problems arise that cannot be neglected, concerning the fate of embryos in storage in case of conflicting situations. Oocyte cryopreservation is rather disappointing at present, and many studies highlight the risks of cryoinjury to the zona pellucida, the meiotic spindle, and other cytoskeletal cell structures. New insights into freezing isolated primordial mouse follicles provide alternate research prospects to store the female gamete.
authors.affiliation: Hôpital Necker Enfants Malades, Institut National de la Sante et de la Recherche Medicale, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Mandelbaum
mesh_terms: D015925:Cryopreservation / Q000379:methods* / Q000592:standards; D004622:Embryo, Mammalian; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D005854:Germ Cells; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome
chemical_list: D007987:Gonadotropin-Releasing Hormone