title: Ultrasound-guided embryo transfer maximizes the IVF results on day 3 and day 4 embryo transfer but has no impact on day 5.
abstract: BACKGROUND
  The use of ultrasound-guided embryo transfer has been reported to affect success rates in some centres but not others. In a prospective study, we examined the influence of ultrasound guidance in embryo transfer performed on different days after oocyte retrieval.
  
  
  METHODS
  Two different methods of embryo transfer were evaluated in 1069 consecutive transfers. The ultrasound-guided embryo transfer was used in 433 cases, whereas 636 embryo transfers were performed with the tactile assessment ('clinical feel') method.
  
  
  RESULTS
  Ultrasound-guided embryo transfer yielded a higher overall pregnancy rate than the 'clinical feel' approach, 47 versus 36% (P < 0.001). This difference was statistically significant where embryos were transferred after 3 or 4 days of culture, 45.9 versus 37.1% (P = 0.001) and 42.3 versus 27% (P = 0.035) respectively but not significant (P = 0.112) on day 5 embryo transfer (56.3 versus 45.7%). Likewise, the implantation rate was significantly different between the two groups on day 3 and 4 embryo transfer, 23.3 versus 15.8% (P < 0.01) and 21.6 versus 15.7% (P < 0.05%) respectively but no statistical difference was noted on day 5 embryo transfer, 26.7 versus 23.6%.
  
  
  CONCLUSIONS
  Ultrasound assistance in embryo transfer on day 3 and 4 significantly improved pregnancy rates in IVF but had no impact on day 5.
authors.affiliation: 4th Department of Obstetrics and Gynaecology, Aristotle University of Thessaloniki, Thessaloniki Greece. iakentro@otenet.gr
authors.forename: Y
authors.initials: Y
authors.lastname: Prapas
authors.forename: N
authors.initials: N
authors.lastname: Prapas
authors.forename: A
authors.initials: A
authors.lastname: Hatziparasidou
authors.forename: P
authors.initials: P
authors.lastname: Vanderzwalmen
authors.forename: M
authors.initials: M
authors.lastname: Nijs
authors.forename: S
authors.initials: S
authors.lastname: Prapa
authors.forename: G
authors.initials: G
authors.lastname: Vlassis
mesh_terms: D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000592:standards*; D005260:Female; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D013997:Time Factors; D014463:Ultrasonography