title: Intracytoplasmic sperm injection as a treatment for unexplained total fertilization failure or low fertilization after conventional in vitro fertilization.
abstract: OBJECTIVE
  To determine whether IVF or intracytoplasmic sperm injection (ICSI) should be the choice of treatment in case of a previous IVF attempt with unexplained total fertilization failure or low fertilization (<25%).
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Leiden University Medical Center.
  
  
  METHODS
  Thirty-eight couples undergoing IVF and ICSI on sibling oocytes after a first IVF attempt with total fertilization failure or with low fertilization (<25%).
  
  
  METHODS
  Performing IVF and ICSI on sibling oocytes.
  
  
  METHODS
  Fertilization and (ongoing) pregnancy rate.
  
  
  RESULTS
  A total of 271 oocytes were collected in 24 oocyte retrievals in the total fertilization failure group. Hundred nine oocytes were randomly allocated to IVF and 12 were fertilized (11%); 162 sibling oocytes were allocated to ICSI and 78 were fertilized (48%). In 8 of the 24 patients fertilization occurred after IVF. The pregnancy rate after transfer of 1 IVF and 1 ICSI embryo (n = 3) was 67% and after the transfer of 2 ICSI embryos (n = 21) this was 52%. In the low fertilization group 169 oocytes were collected in 14 oocyte retrievals. Seventy-two oocytes were randomly allocated to IVF and 16 were fertilized (22%). Ninety-seven sibling oocytes were allocated to ICSI and 58 were fertilized (60%). In 7 of 14 patients fertilization occurred after IVF. The pregnancy rate after the transfer of 1 IVF and 1 ICSI embryo (n = 5) was 80% and after the transfer of 2 ICSI embryos (n = 9) this was 33%.
  
  
  CONCLUSIONS
  Performing ICSI on some oocytes of a cohort may avoid total fertilization failures both in patients with a history of total fertilization failure and in patients with a history of low fertilization, as the percentage of fertilization is higher after ICSI compared to IVF and the recurrence of total fertilization failure and low fertilization is high after IVF treatment.
authors.affiliation: Department of Reproductive Medicine, Leiden University Medical Center, Leiden, The Netherlands. L.A.van_der_Westerlaken@LUMC.nl
authors.forename: Lucette
authors.initials: L
authors.lastname: van der Westerlaken
authors.forename: Frans
authors.initials: F
authors.lastname: Helmerhorst
authors.forename: Sandra
authors.initials: S
authors.lastname: Dieben
authors.forename: Nico
authors.initials: N
authors.lastname: Naaktgeboren
mesh_terms: D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data; D006801:Humans; D007246:Infertility / Q000628:therapy*; D008297:Male; D009865:Oocytes; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000706:statistics & numerical data; D013094:Spermatozoa; D017211:Treatment Failure