title: Sperm preparation before freezing improves sperm motility and reduces apoptosis in post-freezing-thawing sperm compared with post-thawing sperm preparation.
abstract: OBJECTIVE
  To evaluate whether sperm preparation (swim-up technique) before freezing improves the percentages of sperm motility, sperm viability, and non-apoptotic spermatozoa after freezing-thawing process compared with preparation after cryopreservation.
  
  
  METHODS
  Semen samples from 65 infertile males were equally divided into two aliquots one of which was processed for swim-up prior to cryopreservation and one of which was processed following cryopreservation. Sperm count, motility, and apoptosis index were measured in each group.
  
  
  RESULTS
  The total sperm count and the total motile sperm count decreased after thawing in both the pre-preparation and non-preparation groups compared with neat semen group (P < 0.001). Moreover, the percentage of apoptotic sperm in the pre-preparation group after cryopreservation was lower than that in the non-preparation group (P < 0.05), whereas the percentage of vital sperm with progressive motility was higher than that in the pre-preparation group (P < 0.001).
  
  
  CONCLUSIONS
  Semen preparation by swim-up before freezing resulted in better sperm quality and fewer apoptotic sperm than sperm preparation after thawing. Therefore, sperm preparation before cryopreservation should be considered in routine sperm cryopreservation.
authors.affiliation: Reproductive and Biology Unit (RBU), Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand, sispyi@mahidol.ac.th.
authors.forename: Somsin
authors.initials: S
authors.lastname: Petyim
authors.forename: Chanon
authors.initials: C
authors.lastname: Neungton
authors.forename: Isarin
authors.initials: I
authors.lastname: Thanaboonyawat
authors.forename: Pitak
authors.initials: P
authors.lastname: Laokirkkiat
authors.forename: Roungsin
authors.initials: R
authors.lastname: Choavaratana
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000235:genetics*; D015925:Cryopreservation; D004249:DNA Damage / Q000235:genetics; D005434:Flow Cytometry; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000473:pathology; D008297:Male; D055101:Semen Analysis; D012662:Semen Preservation; D013076:Sperm Count; D013081:Sperm Motility / Q000502:physiology*