title: Clinical status of human embryo cryopreservation in the United States of America.
abstract: This report describes the results with frozen human embryos from 25 member institutions of the Society of Assisted Reproductive Technology with cryopreservation experience before 1989. Two thousand eighty-five patients had a total of 7397 oocytes and pre-implantation embryos frozen. The number of oocytes, zygotes, cleaved embryos, and blastocysts frozen, thawed, transferred, and the resulting number of pregnancies were 463/127/8/0, 2,133/778/540/47, 4,460/1,567/1,089/68, and 341/186/138/3, respectively. The number of embryos transferred per pregnancy and pregnancy rate per transfer for zygotes, cleaved embryos, and blastocysts were 11.5/17.4%, 16.0/12.5%, and 46.0/4.3%, respectively. The average number of frozen-thawed embryos transferred per pregnancy was 15.0 and the average clinical pregnancy rate per transfer was 13.4%. Forty-eight births have resulted in 41 singletons and 7 sets of twins. Of centers reporting frozen-thawed transfers, 54.6% (12/22) have at least one clinical pregnancy and 75.0% (9/12) of centers reporting a pregnancy have at least one birth.
authors.affiliation: Genetics & IVF Institute, Fairfax, Virginia 22031.
authors.forename: E F
authors.initials: EF
authors.lastname: Fugger
mesh_terms: D015925:Cryopreservation; D004624:Embryo Transfer; D004622:Embryo, Mammalian; D005307:Fertilization in Vitro; D006801:Humans; D009865:Oocytes; D011795:Surveys and Questionnaires; D014481:United States