title: How do cumulative live birth rates and cumulative multiple live birth rates over complete courses of assisted reproductive technology treatment per woman compare among registries?
abstract: OBJECTIVE
  How do the national cumulative (multiple) live birth rates over complete assisted reproduction technology (ART) courses of treatment per woman in Belgium compare to those in other registries?
  
  
  CONCLUSIONS
  Cumulative live birth rates (CLBRs) remain high with a low cumulative multiple live birth rate when compared with other registries and publications.
  
  
  BACKGROUND
  In ART, a reduction in the multiple live birth rate could be achieved by reducing the number of embryos transferred. It has been shown that by doing so, live birth rates per cycle were maintained, particularly when the augmentation effect of attached frozen-thawed cycles was considered.
  
  
  METHODS
  A retrospective cohort study included all patients with a Belgian national insurance number who were registered in the national ART registry (Belrap) and who started a first fresh ART cycle between 1 July 2009 until 31 December 2011 with follow up until 31 December 2012. We analysed 12 869 patients and 38 008 cycles (both fresh and attached frozen cycles).
  CLBRs per patient who started a first ART cycle including fresh and consecutive frozen cycles leading to a live birth. Conservative estimates of cumulative live birth assumed that patients who did not return for treatment had no chance of achieving an ART-related live birth, whereas optimal estimates assumed that women discontinuing treatment would have the same chance of achieving a live birth as those continuing treatment. A maximum of six fresh ART cycles with corresponding frozen cycles was investigated and compared with other registries and publications.
  
  
  RESULTS
  The CLBR was age dependent and declined from 62.9% for women <35 years, to 51.4% for women 35-37 years, to 34.1% for women 38-40 years and 17.7% for women 41-42 years in the conservative analysis after six cycles. In the optimal estimate, the CLBR declined from 85.9% for women <35 years, to 72.0% for women 35-37 years, to 50.4% for women 38-40 years and 36.4% for women 41-42 years. The cumulative multiple live birth rates for the whole population were 5.1 and 8.6% for the conservative and optimal estimate, respectively.
  
  
  CONCLUSIONS
  Conservative and optimal estimates use assumptions for the whole ART population and do not take the individual patient into account.
  
  
  CONCLUSIONS
  These data reinforce the validity of the Belgian model of coupling reimbursement of ART costs to a restriction in the number of embryos transferred. Our data can improve decision-making in medical ART practice both on the patient level and for society at large and could provide health care takers and insurance companies with a valid model.
  none.
authors.affiliation: Leuven University Fertility Centre, University Hospitals Leuven, 3000 Leuven, Belgium diane.deneubourg@telenet.be.
authors.forename: D
authors.initials: D
authors.lastname: De Neubourg
authors.affiliation: I-BioStat, KU Leuven, 3000 Leuven and Universiteit Hasselt, 3500 Hasselt, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Bogaerts
authors.affiliation: Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Blockeel
authors.affiliation: Fertility Centre, AZ St Lucas, 9000 Ghent, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Coetsier
authors.affiliation: Centre de Procréation Médicalement Assistée, Clinique Saint-Vincent, 4000 Liège, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Delvigne
authors.affiliation: Laboratoire de Procréation Médicalement Assistée, Université Libre de Bruxelles, Hôpital Erasme, 1070 Brussels, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Devreker
authors.affiliation: Centre de Procréation Médicalement Assistée, Université de Liège, 4000 Liège, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Dubois
authors.affiliation: Nutrition, Environment and Health, University of Liège, 4000 Liège, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Gillain
authors.affiliation: Leuven Institute for Fertility and Embryology, 3000 Leuven, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Gordts
authors.affiliation: Department of Gynaecology-Andrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, 1200 Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Wyns
mesh_terms: D000328:Adult; D001530:Belgium / Q000453:epidemiology; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology / Q000628:therapy*; D050498:Live Birth / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D011247:Pregnancy; D012042:Registries / Q000706:statistics & numerical data*; D027724:Reproductive Techniques, Assisted / Q000706:statistics & numerical data*
keywords: assisted reproduction technology; conservative estimate; cumulative live birth rate; cumulative multiple live birth rate; optimal estimate; registry