title: Pregnancies and births after oocyte cryopreservation.
abstract: OBJECTIVE
  To determine the potential of oocyte cryopreservation techniques.
  
  
  METHODS
  Retrospective data analysis.
  
  
  METHODS
  A tertiary infertility center.
  
  
  METHODS
  Sixty-eight patients (29 to 37 years of age) undergoing assisted reproduction procedures for infertility problems.
  
  
  METHODS
  Oocytes from women treated for infertility were cryopreserved with a slow cooling/rapid thawing protocol in which 1,2 propanediol and sucrose were used as cryoprotectants. Eighty-six thawing cycles were performed.
  
  
  METHODS
  Rates of survival after thawing, fertilization after intracytoplasmic sperm injection, cleavage, implantation, and pregnancy.
  
  
  RESULTS
  We treated 68 patients through 86 thawing cycles. Seven hundred thirty-seven oocytes were thawed, and 59 transfer cycles were performed. The survival rate was 37%. The fertilization and cleavage rates were 45.4% and 86.3%, respectively. A total of 15 clinical pregnancies were achieved with pregnancy rates of 25.4% per transfer and 22% per patient. There were three miscarriages, resulting in an abortion rate of 20%. Seventeen of the 104 transferred embryos implanted, corresponding to an implantation rate of 16.4%. Thirteen babies were born, 8 females and 5 males.
  
  
  CONCLUSIONS
  Statistically significant results were obtained for fertilization, cleavage, and pregnancy rates. Our results show oocyte cryopreservation may represent an alternative to embryo storage in selected cases.
authors.affiliation: Tecnobios Procreazione, Via Dante 15, 40125 Bologna, Italy. borini@tecnobios.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Borini
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Bonu
authors.forename: Giovanni
authors.initials: G
authors.lastname: Coticchio
authors.forename: Veronica
authors.initials: V
authors.lastname: Bianchi
authors.forename: Monica
authors.initials: M
authors.lastname: Cattoli
authors.forename: Carlo
authors.initials: C
authors.lastname: Flamigni
mesh_terms: D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods; D010064:Embryo Implantation; D005260:Female; D006801:Humans; D009865:Oocytes / Q000166:cytology*; D011247:Pregnancy; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic