title: Analysis of oocyte cryopreservation in assisted reproduction: the Italian National Register data from 2005 to 2007.
abstract: This paper reports on oocyte cryopreservation efficacy in Italy with respect to successful IVF from 2005 to 2007, presenting data from 193 centres collected by the Italian National Register. Post-thawing survival rates, number of transferred embryos, implantation rates and clinical pregnancy rates per transfer with respect to frozen/vitrified oocytes (FVO) were analysed. These numbers were compared with those obtained using frozen embryos or fresh oocytes. A total of 121,708 cycles were initiated, of which, 7.1% (8682) were FVO cycles and 2.4% (2952) were frozen embryo cycles. Of the 81,786 FVO, 52.5% (42,917) were thawed and 26.9% (22,005) inseminated. Of those inseminated, 68.0% (14,966) yielded good embryos. These numbers were significantly lower than those using fresh oocytes in which 77.9% (197,242; fresh oocytes versus FVO P<0.001) of inseminated oocytes generated good embryos. Implantation rate using FVO was 6.9%, which was significantly lower than that using fresh oocytes (13.5%; P<0.001) and frozen embryos (8.8%; P<0.001). Pregnancy rate per transfer using FVO was 12.5% and significantly lower than that using fresh oocytes (24.9%; P<0.001) or frozen embryos (16.4%; P<0.001). There were 505 deliveries after IVF with FVO and 582 babies.
authors.affiliation: ART Italian National Register, National Centre for Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, 00161 Rome, Italy. giulia.scaravelli@iss.it
authors.forename: G
authors.initials: G
authors.lastname: Scaravelli
authors.forename: V
authors.initials: V
authors.lastname: Vigiliano
authors.forename: J M
authors.initials: JM
authors.lastname: Mayorga
authors.forename: S
authors.initials: S
authors.lastname: Bolli
authors.forename: R
authors.initials: R
authors.lastname: De Luca
authors.forename: P
authors.initials: P
authors.lastname: D'Aloja
mesh_terms: D000013:Congenital Abnormalities / Q000453:epidemiology; D015925:Cryopreservation / Q000379:methods*; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D005615:Freezing; D006801:Humans; D007558:Italy / Q000453:epidemiology; D009865:Oocytes; D011247:Pregnancy; D018873:Pregnancy Rate; D058989:Vitrification