title: [Human embryo cryopreservation: current state in France (1985-1993). French Federation of IVF Biologists].
abstract: The French Federation of IVF Biologists (BLEFCO) reports the first survey on the fate of 102,812 human embryos frozen in France during a nine-year period (1985-1993). Ninety-four per cent of surviving embryos were transferred to the parental couple, 6% were thawed to conclude their storage while embryo donation remained exceptional (0.2%). Fifty-five per cent of all thawed embryos survived the freeze-thaw procedure. However, only 3.5% of the transferred embryos achieved full-term development (as compared to 9% for unfrozen embryos). Thus, embryo freezing efficiency remains low but high14 variable among different centers. Therefore, cryopreservation has led to the birth of more than 1,200 babies and for several group, has contributed up to 22% of IVF deliveries. The variability observed in the results can be largely related to the adequacy of programmable freezers. Indeed, 68% of frozen embryos survived after thawing in case of manual seeding (15% pregnancy per transfer) versus 42% in case of automatic seeding (9% pregnancy per transfer p < 0.001). Freezing has no adverse effect on the rate of anomalies at birth (1.8%).
mesh_terms: D015925:Cryopreservation / Q000706:statistics & numerical data* / Q000639:trends; D004622:Embryo, Mammalian; D005260:Female; D005307:Fertilization in Vitro; D005602:France; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D011795:Surveys and Questionnaires
vernacular_title: Congélation des embryons humains: enquête sur la situation en France (1985-1993). Fédération des BLEFCO.