title: Frozen-thawed epididymal spermatozoa for intracytoplasmic sperm injection.
abstract: OBJECTIVE
  To report the fertilization rate and pregnancy results for intracytoplasmic sperm injection (ICSI) cycles using frozen-thawed epididymal spermatozoa.
  
  
  METHODS
  Retrospective analysis of consecutive ICSI cycles.
  
  
  METHODS
  Tertiary referral center for infertility.
  
  
  METHODS
  Infertile couples in whom 39 patients (59 ICSI cycles) required the use of frozen-thawed epididymal spermatozoa. As no cycles were performed using fresh epididymal spermatozoa, outcomes were compared with those of 130 couples (170 ICSI cycles) using fresh ejaculated spermatozoa for severe oligoasthenozoospermia-teratozoospermia, in which < 200,000 motile spermatozoa were retrieved after Percoll density gradient centrifugation.
  
  
  METHODS
  Epididymal sperm aspiration during microsurgery, followed by ICSI.
  
  
  METHODS
  Fertilization, embryo cleavage, ET, and clinical pregnancy rates (PRs).
  
  
  RESULTS
  A total of 484 metaphase II oocytes were injected with frozen-thawed epididymal spermatozoa, resulting in a two-pronuclear fertilization rate per injected metaphase II oocyte of 47%, significantly lower than in cycles using fresh ejaculated spermatozoa (73%). Embryo implantation rates (12.0% versus 13.3%) and clinical PRs per transfer (18.4% versus 27.0%) were not different. When the prefreeze vitality was > 20%, compared with lower vitality, both the fertilization (56% versus 22%) and embryo cleavage (91% versus 57%) rates were significantly greater.
  
  
  CONCLUSIONS
  The routine collection and cryopreservation of epididymal spermatozoa at microsurgery allows multiple ICSI treatment cycles with success rates similar to those of ejaculated spermatozoa. However, when the vitality of aspirated spermatozoa is < 20%, the poor fertilization rates indicate the need to consider an alternative source of viable spermatozoa.
authors.affiliation: Monash IVF, Epworth Hospital, Richmond, Victoria, Australia.
authors.forename: C A
authors.initials: CA
authors.lastname: Holden
authors.forename: G F
authors.initials: GF
authors.lastname: Fuscaldo
authors.forename: P
authors.initials: P
authors.lastname: Jackson
authors.forename: A
authors.initials: A
authors.lastname: Cato
authors.forename: G J
authors.initials: GJ
authors.lastname: Southwick
authors.forename: R
authors.initials: R
authors.lastname: Hauser
authors.forename: P D
authors.initials: PD
authors.lastname: Temple-Smith
authors.forename: R I
authors.initials: RI
authors.lastname: McLachlan
mesh_terms: D000328:Adult; D015925:Cryopreservation; D003593:Cytoplasm; D004822:Epididymis; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D008875:Middle Aged; D009845:Oligospermia / Q000628:therapy; D011247:Pregnancy; D012189:Retrospective Studies; D013081:Sperm Motility