title: Best site for embryo transfer: the upper or lower half of endometrial cavity?
abstract: BACKGROUND
  The objective of the present study was to determine the importance of the site of embryo transfer (upper or lower half endometrial cavity) on implantation and clinical pregnancy rates.
  
  
  METHODS
  A total of 400 transfers guided by ultrasound were randomly assigned to two groups according to the distance between the uterine fundus and the catheter tip at the time of embryo placement. Group I (n = 200) consisted of transfers corresponding to a distance of < 50% of the endometrial cavity length (ECL), i.e. transfer in upper half of the cavity; and group II (n = 200) consisted of transfers corresponding to a distance of > or = 50%, of the ECL, i.e. transfer in lower half of cavity. The Student's t-test, Mann-Whitney test and Fisher's exact test were used where appropriate.
  
  
  RESULTS
  The general characteristics of the study population and the main transfer cycle characteristics had an equal distribution (P > 0.05) between groups I and II. No significant difference in implantation or pregnancy rates was observed between groups I and II.
  
  
  CONCLUSIONS
  The implantation or pregnancy rates were similar whether the embryos were deposited in the upper or lower half of the endometrial cavity.
authors.affiliation: Center for Human Reproduction, Sinhá Junqueira Maternity Foundation, Ribeirão Preto, SP, Brazil. crh@crh.com.br
authors.forename: J G
authors.initials: JG
authors.lastname: Franco
authors.forename: A M V C
authors.initials: AM
authors.lastname: Martins
authors.forename: R L R
authors.initials: RL
authors.lastname: Baruffi
authors.forename: A L
authors.initials: AL
authors.lastname: Mauri
authors.forename: C G
authors.initials: CG
authors.lastname: Petersen
authors.forename: V
authors.initials: V
authors.lastname: Felipe
authors.forename: P
authors.initials: P
authors.lastname: Contart
authors.forename: A
authors.initials: A
authors.lastname: Pontes
authors.forename: J B A
authors.initials: JB
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer; D004717:Endometrium / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D014463:Ultrasonography