title: Reproductive potential of fresh and cryopreserved epididymal and testicular spermatozoa in consecutive intracytoplasmic sperm injection cycles in the same patients.
abstract: OBJECTIVE
  To determine if the cryopreservation of epididymal and testicular spermatozoa alters their reproductive potential by examination of patients who underwent consecutive cycles of ICSI using fresh and then cryopreserved spermatozoa.
  
  
  METHODS
  Retrospective review.
  
  
  METHODS
  Tertiary care university hospital.
  
  
  METHODS
  One hundred sixty-two consecutive cycles of ICSI were analyzed. Thirteen patients were identified as having undergone treatment with freshly retrieved epididymal spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. Eighteen patients underwent ICSI with freshly retrieved testicular spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle.
  
  
  METHODS
  None.
  
  
  METHODS
  Fertilization rates and pregnancy rates.
  
  
  RESULTS
  The fertilizing capacity of epididymal spermatozoa remained unchanged after cryopreservation and subsequent thawing, with fertilization rates of 58% and 57% for fresh and cryopreserved spermatozoa, respectively. Testicular spermatozoa, however, showed a significant decrease in fertilizing capacity after cryopreservation when compared with freshly retrieved spermatozoa (52% and 71%, respectively). Pregnancy rates appeared unaffected by the cryopreservation of epididymal spermatozoa (fresh, 3/13; frozen, 2/13) or testicular spermatozoa (fresh, 2/18; frozen, 5/18).
  
  
  CONCLUSIONS
  This study offers further evidence that motile epididymal spermatozoa retain their fertilizing capacity after cryopreservation. The data presented on testicular spermatozoa suggest that although cryopreservation may reduce the fertilizing capacity of testicular spermatozoa, there is no decrease in pregnancy rates.
authors.affiliation: Reproductive Medicine Unit, Liverpool Women's Hospital, England, UK. simon_j.wood@virgin.net
authors.forename: Simon
authors.initials: S
authors.lastname: Wood
authors.forename: Kevin
authors.initials: K
authors.lastname: Thomas
authors.forename: Karen
authors.initials: K
authors.lastname: Schnauffer
authors.forename: Stephen
authors.initials: S
authors.lastname: Troup
authors.forename: Charles
authors.initials: C
authors.lastname: Kingsland
authors.forename: Iwan
authors.initials: I
authors.lastname: Lewis-Jones
mesh_terms: D000328:Adult; D015925:Cryopreservation; D004822:Epididymis; D005260:Female; D005306:Fertilization; D006801:Humans; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000502:physiology*; D013737:Testis