title: [Value of cryopreservation of human embryos during the blastocyst stage].
abstract: The recent development of co-culture technique has permitted to cryopreserve human embryos at the blastocyst stage. The aim of the present study was to compare pregnancy rates after transfers of embryos frozen at an early embryo stage (2-8 cell stage, group A; n = 175) with others frozen at blastocyst stage (group B; n = 98). Our results demonstrated that the frozen/thawed blastocyst survival is approximately 100%. In comparison the early embryos survival rate was 59% (P < 0.05). Moreover, pregnancy rates/embryo transfer in group A (16.4%) were significantly improved by comparison to those observed with early embryos (6.2%) (P < 0.05). In conclusion, our results demonstrate that embryo frozen/thawed at the blastocyst stage can be useful for improving pregnancy rates after cryopreservation.
authors.affiliation: Unité clinique de PMA, Hôpital A. Béclere, Clamart.
authors.forename: S
authors.initials: S
authors.lastname: Freitas
authors.forename: F
authors.initials: F
authors.lastname: Le Gal
authors.forename: A
authors.initials: A
authors.lastname: Dzik
authors.forename: M
authors.initials: M
authors.lastname: Volante
authors.forename: C
authors.initials: C
authors.lastname: Lelaidier
authors.forename: F
authors.initials: F
authors.lastname: Olivennes
authors.forename: R
authors.initials: R
authors.lastname: Fanchin
authors.forename: D
authors.initials: D
authors.lastname: de Ziegler
authors.forename: A
authors.initials: A
authors.lastname: Hazout
authors.forename: R
authors.initials: R
authors.lastname: Frydman
mesh_terms: D001755:Blastocyst; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer / Q000379:methods*; D004622:Embryo, Mammalian; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D015996:Survival Rate
vernacular_title: Intérêt de la congélation des embryons humains au stade de blastocyste.