title: The role of in vitro fertilization and intracytoplasmic sperm injection in couples with unexplained infertility after failed intrauterine insemination.
abstract: OBJECTIVE
  To determine an optimal insemination technique in patients undergoing IVF after failed IUI and the role of intracytoplasmic sperm injection (ICSI) in such cases.
  
  
  METHODS
  Prospective, randomized study in couples with unexplained infertility (n = 63) and mild endometriosis (n = 7) undergoing IVF after four IUI cycles. Sibling oocytes were randomized into standard IVF or ICSI insemination according to the order of retrieval.
  
  
  METHODS
  In vitro fertilization program at the Instituto Valenciano de Infertilidad, Valencia, Italy.
  
  
  METHODS
  Seventy couples with unexplained infertility undergoing IVF after failing to conceive with controlled ovarian stimulation and IUI.
  
  
  METHODS
  In vitro fertilization and ICSI.
  
  
  METHODS
  Fertilization, cleavage, and embryo quality were compared in IVF- and ICSI-inseminated oocytes.
  
  
  RESULTS
  There was no significant difference in fertilization rates between ICSI (60.4%) and conventional IVF (54.0%). Similarly, there was no difference in embryo quality between both groups. There was no total fertilization failure in ICSI-inseminated oocytes, whereas 8 (11.4%) of 70 cases showed absence of fertilization when conventional IVF was used.
  
  
  CONCLUSIONS
  Couples with unexplained infertility and mild endometriosis failing to conceive with IUI and undergoing IVF have an 11.4% chance of fertilization failure that can be overcome easily by using ICSI in at least some oocytes. ICSI, however, is not superior to IVF as an insemination technique in most cases. These data should be used in counseling patients.
authors.affiliation: Instituto Valenciano de Infertilidad, Valencia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ruiz
authors.forename: J
authors.initials: J
authors.lastname: Remohí
authors.forename: Y
authors.initials: Y
authors.lastname: Minguez
authors.forename: P P
authors.initials: PP
authors.lastname: Guanes
authors.forename: C
authors.initials: C
authors.lastname: Simón
authors.forename: A
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D000328:Adult; D003376:Counseling; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007246:Infertility / Q000628:therapy*; D008297:Male; D008845:Microinjections / Q000379:methods; D018873:Pregnancy Rate; D011446:Prospective Studies