title: Ultrasound-guided embryo transfer and the accuracy of trial embryo transfer.
abstract: BACKGROUND
  Studies have suggested that ultrasound-guided embryo transfer (UG-ET) may improve the outcome in IVF; however, several factors may account for the improvement in pregnancy rate. This study examines the use of ultrasound to determine the accuracy of trial transfer (TT) in preparation for ET.
  
  
  METHODS
  Sixty-seven consecutive patients prospectively underwent UG-ET over a 2 month period. Total cavity length by US was compared with the length noted by TT. A difference of > or = 1 cm was considered significant. All embryos were placed within 1-2 cm of the fundus by US.
  
  
  RESULTS
  Twenty patients (29.9%) had a difference of > or = 1 cm and 13 patients (19.4%) had a difference of < or = 1.5 cm. Patients with a difference of > or = 1 or > or = 1.5 cm had a significantly greater depth at transfer (P < 0.001) and uterine cavity length (P < 0.001) when compared with patients without a difference. Clinical pregnancy, implantation, delivery and overall miscarriage rates did not differ between patients with a difference of > or = 1 or > or = 1.5 cm versus no difference. There were no ectopic pregnancies.
  
  
  CONCLUSIONS
  Nineteen percent of patients had a discrepancy of > or = 1.5 cm and approximately 30% had a difference of > or = 1 cm from TT at UG-ET, suggesting a benefit to UG-ET. A large prospective randomized trial comparing UG-ET with blind transfer is required to assess further if UG-ET should be used in all cases of ET.
authors.affiliation: Cornell Center for Reproductive Medicine, 505 East 70th Street, 3rd floor, New York, NY 10021, USA.
authors.forename: Mousa I
authors.initials: MI
authors.lastname: Shamonki
authors.forename: Steven D
authors.initials: SD
authors.lastname: Spandorfer
authors.forename: Zev
authors.initials: Z
authors.lastname: Rosenwaks
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D015994:Incidence; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging*