title: The impact of the embryo transfer catheter on the pregnancy rate in IVF.
abstract: BACKGROUND
  The aim was to assess whether the type of embryo transfer set used for embryo transfer affects the ongoing pregnancy rate in IVF.
  
  
  METHODS
  The TDT set was compared with the K-soft 5000 in a large, prospective, randomized study. Patients were randomized moments before transfer by drawing a consecutively numbered, sealed, opaque envelope indicating the catheter to be used.
  
  
  RESULTS
  2059 embryo transfers in 1296 patients were analysed. The ongoing pregnancy rate was significantly higher in the K-soft group. If the first transfer of a patient (n = 1296) within this study period was analysed, the ongoing pregnancy rates were 27.1 versus 20.5% (P = 0.006). If the analysis is limited to patients that underwent their very first transfer ever (n = 607), the ongoing pregnancy rates were 30.3 versus 20.0% (P = 0.003) in favour of the K-soft.
  
  
  CONCLUSIONS
  We conclude from these data that the type of embryo transfer set used for embryo transfer does affect the ongoing pregnancy rate and that the impact of the variable transfer catheter on the ongoing pregnancy rate increases when the a priori chance of pregnancy increases.
authors.affiliation: Department of Obstetrics, Gynaecology and Reproductive Medicine, VU University Medical Centre, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands. h.vanweering@vumc.nl
authors.forename: Hans G I
authors.initials: HG
authors.lastname: van Weering
authors.forename: Roel
authors.initials: R
authors.lastname: Schats
authors.forename: Joseph
authors.initials: J
authors.lastname: McDonnell
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Vink
authors.forename: Jan P W
authors.initials: JP
authors.lastname: Vermeiden
authors.forename: Peter G A
authors.initials: PG
authors.lastname: Hompes
mesh_terms: D000328:Adult; D002404:Catheterization; D004624:Embryo Transfer / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies