title: Unexplained infertility: overall ongoing pregnancy rate and mode of conception.
abstract: BACKGROUND
  Unexplained infertility is one of the most common diagnoses in fertility care. The aim of this study was to evaluate the outcome of current fertility management in unexplained infertility.
  
  
  METHODS
  In an observational, longitudinal, multicentre cohort study, 437 couples were diagnosed with unexplained infertility and were available for analysis. They were treated according to their prognosis using standing national treatment protocols: (i) expectant management-IUI-IVF (main treatment route), (ii) IUI-IVF and (iii) directly IVF. Primary outcome measures were: ongoing pregnancy rate, patient flow over the strategies, numbers of protocol violation and drop out rates. A secondary outcome measure was the prediction of ongoing pregnancy and mode of conception.
  
  
  RESULTS
  Of all couples 81.5% (356/437) achieved an ongoing pregnancy and 73.9% (263/356) of the pregnancies were conceived spontaneously. There were 408 couples (93.4%) in strategy-1, 21 (5.0%) in strategy-2 and 8 (1.8%) in strategy-3. In total, 33 (7.6%) couples entered the wrong strategy. There were 104 couples (23.8%) who discontinued fertility treatment prematurely: 26 on doctor's advice (with 4 still becoming pregnant) and 78 on their own initiative (with 33 still achieving a pregnancy). Predictors for overall pregnancy chance and mode of conception were duration of infertility, female age and obstetrical history.
  
  
  CONCLUSIONS
  Overall success rate in couples with unexplained infertility is high. Most pregnancies are conceived spontaneously. We recommend that if the pregnancy prognosis is good, expectant management should be suggested. The prognosis criteria for treatment with IUI or IVF needs to be investigated in randomized controlled trials.
authors.affiliation: Department of Obstetrics and Gynaecology, Jeroen Bosch Hospital, PO Box 90153, 5200 ME 's-Hertogenbosch, The Netherlands. m.brandes@jbz.nl
authors.forename: M
authors.initials: M
authors.lastname: Brandes
authors.forename: C J C M
authors.initials: CJ
authors.lastname: Hamilton
authors.forename: J O M
authors.initials: JO
authors.lastname: van der Steen
authors.forename: J P
authors.initials: JP
authors.lastname: de Bruin
authors.forename: R S G M
authors.initials: RS
authors.lastname: Bots
authors.forename: W L D M
authors.initials: WL
authors.lastname: Nelen
authors.forename: J A M
authors.initials: JA
authors.lastname: Kremer
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007246:Infertility / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands; D011247:Pregnancy; D018873:Pregnancy Rate; D011379:Prognosis