title: Fertilization and pregnancy outcome after intracytoplasmic injection with fresh or cryopreserved ejaculated spermatozoa.
abstract: OBJECTIVE
  To assess fertilization, implantation, and pregnancy rates in patients undergoing ICSI using fresh and cryopreserved sperm from ejaculated semen samples.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Academic and private medical centers.
  
  
  METHODS
  One hundred fifty-eight patients.
  
  
  METHODS
  Intracytoplasmic sperm injection.
  
  
  METHODS
  Fertilization, implantation, and pregnancy rates were evaluated; 61 cycles of ICSI were performed with cryopreserved and 79 cycles of ICSI were performed with fresh spermatozoa. Also, we divided the outcomes according to the semen characteristics, normozoospermia, oligozoospermia, asthenozoospermia, and oligoasthenozoospermia.
  
  
  RESULTS
  Overall, normal-fertilization rates were higher using fresh sperm (73.8%) compared with cryopreserved sperm (68.7%). Cycles performed in patients with normozoospermia or oligozoospermia had similar fertilization, implantation, and pregnancy rates using fresh or cryopreserved sperm. When asthenozoospermic and oligoasthenozoospermic semen samples were used, the normal-fertilization rate was higher with fresh sperm compared with cryopreserved sperm. However, implantation and pregnancy rates were similar in fresh and cryopreserved sperm samples from patients with asthenozoospermia or oligoasthenozoospermia.
  
  
  CONCLUSIONS
  Semen with abnormalities in the motility may be more susceptible to sperm cryopreservation damage, resulting in lower fertilization rates. However, once the oocyte is fertilized, implantation and pregnancy rates are similar to those in patients with oligozoospermia and normozoospermia.
authors.affiliation: Fertility-Assisted Fertilization Center, São Paulo, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Borges
authors.forename: Lia Mara
authors.initials: LM
authors.lastname: Rossi
authors.forename: Christiany Victor
authors.initials: CV
authors.lastname: Locambo de Freitas
authors.forename: Patrícia
authors.initials: P
authors.lastname: Guilherme
authors.forename: Tatiana Carvalho S
authors.initials: TC
authors.lastname: Bonetti
authors.forename: Assumpto
authors.initials: A
authors.lastname: Iaconelli
authors.forename: Fabio Firmbach
authors.initials: FF
authors.lastname: Pasqualotto
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D015925:Cryopreservation / Q000706:statistics & numerical data*; D004542:Ejaculation; D005260:Female; D005306:Fertilization; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000628:therapy*; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome