title: Pregnancy with frozen-thawed and fresh testicular biopsy after motile and immotile sperm microinjection, using the mechanical touch technique to assess viability.
abstract: BACKGROUND
  There are few reports of pregnancy using immotile sperm, and none using a purely mechanical assessment of viability.
  
  
  METHODS
  In this pilot study, we retrospectively analysed 66 cycles in 61 patients with determinant male factor, recording rates of fertilization, implantation, normal pregnancy and take-home babies achieved with ICSI. Sperm selection was based on morphologically normal appearance under the inverted microscope. Viability of immotile spermatozoa was assessed by the mechanical touch technique to observe tail flexibility and tail shape recovery.
  
  
  RESULTS
  Of 17 ICSI cycles using frozen-thawed testicular sperm, six microinjected with immotile and 11 with motile sperm, we achieved fertilization rates of 65.7 and 74.3%, respectively, and five pregnancies (two and three, respectively). Of 49 ICSI cycles using fresh testicular sperm, 10 microinjected with immotile and 39 with motile sperm, we achieved fertilization rates of 73.4 and 64.4%, respectively, and 12 pregnancies (three and nine, respectively).
  
  
  CONCLUSIONS
  Immotile (fresh and frozen-thawed) testicular sperm of normal morphological appearance can be used to achieve clinical pregnancy with ICSI. Our results strongly suggest that immotile sperm viability can be assessed by the mechanical touch technique.
authors.affiliation: Hospital Universitario de Canarias, Servicio de Ginecología y Obstetricia, Unidad de Reproducción Humana,Carretera General, Ofra S/N La Cuesta, 38320 La Laguna, Santa Cruz de Tenerife, Spain. neudam@hotmail.com
authors.forename: Neuda Marques
authors.initials: NM
authors.lastname: de Oliveira
authors.forename: Rebeca
authors.initials: R
authors.lastname: Vaca Sánchez
authors.forename: Sonsoles
authors.initials: S
authors.lastname: Rodriguez Fiesta
authors.forename: Tomas
authors.initials: T
authors.lastname: Lopez Salgado
authors.forename: Rubi
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Jose C Alberto
authors.initials: JC
authors.lastname: Bethencourt
authors.forename: Raquel
authors.initials: R
authors.lastname: Blanes Zamora
mesh_terms: D000328:Adult; D001706:Biopsy; D002470:Cell Survival; D015925:Cryopreservation; D010064:Embryo Implantation; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007248:Infertility, Male / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology; D013737:Testis / Q000166:cytology*; D016896:Treatment Outcome