title: A prediction model for selecting patients undergoing in vitro fertilization for elective single embryo transfer.
abstract: OBJECTIVE
  Construction of a prediction model to enable the selection of patients for elective single ET.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Fertility center in a tertiary referral university hospital.
  
  
  METHODS
  Six hundred forty-two women undergoing their first IVF treatment cycle in which no more than two embryos were transferred.
  
  
  METHODS
  Database analysis.
  
  
  METHODS
  Ongoing pregnancy and multiple pregnancy.
  
  
  RESULTS
  In multivariate analysis, the best predictors for ongoing pregnancy were female age, the number of retrieved oocytes, the developmental stage score and the morphology score of the two best embryos available for transfer, and the day of transfer. Younger age and high quality of transferred embryos were the best predictors for increased risk of multiple pregnancy. The resulting model enables the calculation of probabilities of pregnancy and twin pregnancy. Depending on embryo quality, there is a threshold age under which the chance of singleton pregnancy is higher if one embryo is transferred compared with two embryos.
  
  
  CONCLUSIONS
  Application of this model may enable a reduction in the chance of twin pregnancy without compromising singleton pregnancy rates in a subgroup of patients undergoing IVF.
authors.affiliation: Division of Reproductive Medicine, Department of Obstetrics and Gynecology, Erasmus University Medical Center, The, Rotterdam, Netherlands.
authors.forename: Claudine C
authors.initials: CC
authors.lastname: Hunault
authors.forename: Marinus J C
authors.initials: MJ
authors.lastname: Eijkemans
authors.forename: Math H E C
authors.initials: MH
authors.lastname: Pieters
authors.forename: Egbert R
authors.initials: ER
authors.lastname: te Velde
authors.forename: J Dik F
authors.initials: JD
authors.lastname: Habbema
authors.forename: Bart C J M
authors.initials: BC
authors.lastname: Fauser
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Macklon
mesh_terms: D000328:Adult; D000375:Aging; D000704:Analysis of Variance; D002452:Cell Count; D015331:Cohort Studies; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D016015:Logistic Models; D016017:Odds Ratio; D009865:Oocytes; D006080:Ovarian Follicle / Q000033:anatomy & histology; D018579:Patient Selection; D011247:Pregnancy; D011272:Pregnancy, Multiple; D012372:ROC Curve; D012189:Retrospective Studies; D013076:Sperm Count; D014427:Twins