title: Embryo implantation rates in oocyte donation: a prospective comparison of tubal versus uterine transfers.
abstract: OBJECTIVE
  To compare pregnancy and implantation rates in tubal and uterine transfers during a hormonal replacement cycle in an oocyte donation program.
  
  
  METHODS
  Prospective randomized.
  
  
  METHODS
  Forty-two consecutive patients who entered an oocyte donation program.
  
  
  METHODS
  Twenty-two patients were assigned for uterine transfer and 20 for tubal embryo transfer (ET).
  
  
  RESULTS
  Twenty-three pregnancies were achieved, 12 (54.5%) after uterine transfers and 11 (57.9%) after tubal transfers. Implantation rates in both groups are not significantly different (17.4% uterine transfers versus 21.5% tubal ETs).
  
  
  CONCLUSIONS
  Our results suggest that in hormonal replacement cycles (uniform endometrial stimulation) there is no advantage in transferring embryos to the fallopian tube. Furthermore, embryo quality and endometrial receptivity appear to be significantly more important than the time of entrance of an embryo to the uterine cavity in determining its chances of implantation.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, University of California, Irvine, Orange.
authors.forename: J P
authors.initials: JP
authors.lastname: Balmaceda
authors.forename: V
authors.initials: V
authors.lastname: Alam
authors.forename: D
authors.initials: D
authors.lastname: Roszjtein
authors.forename: T
authors.initials: T
authors.lastname: Ord
authors.forename: K
authors.initials: K
authors.lastname: Snell
authors.forename: R H
authors.initials: RH
authors.lastname: Asch
mesh_terms: D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods*; D005187:Fallopian Tubes; D005260:Female; D006801:Humans; D009865:Oocytes; D011247:Pregnancy; D011446:Prospective Studies; D014019:Tissue Donors; D014599:Uterus