title: Treatment of patients with long-standing unexplained subfertility with in vitro fertilization.
abstract: OBJECTIVE
  To evaluate whether IVF is an effective treatment for long-standing unexplained subfertility.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Tertiary care infertility center in a university hospital.
  
  
  METHODS
  Two hundred two couples with unexplained subfertility of 2 years' duration or more who attended the center for their first IVF attempt.
  
  
  METHODS
  Couples were placed on a waiting list for IVF. They received no treatment until IVF was started.
  
  
  METHODS
  Pregnancy rate (PR) while on the waiting list and PR after IVF treatment.
  
  
  RESULTS
  Complete data sets were available for 131 couples. Seventeen of 131 women became pregnant while waiting for IVF treatment (PR 0.9% per exposure cycle), whereas 45 of 119 receiving IVF treatment became pregnant (PR 17% per IVF attempt).
  
  
  CONCLUSIONS
  IVF treatment has substantial added value over waiting and is an efficient treatment for long-standing unexplained subfertility.
authors.affiliation: Division of Reproductive Medicine, University Hospital Groningen, The Netherlands. p.f.j.donderwinkel@oprit.rug.nl
authors.forename: P F
authors.initials: PF
authors.lastname: Donderwinkel
authors.forename: H
authors.initials: H
authors.lastname: van der Vaart
authors.forename: V M
authors.initials: VM
authors.lastname: Wolters
authors.forename: A H
authors.initials: AH
authors.lastname: Simons
authors.forename: G
authors.initials: G
authors.lastname: Kroon
authors.forename: M J
authors.initials: MJ
authors.lastname: Heineman
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D015993:Life Tables; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013997:Time Factors