title: The correlation between endometrial thickness and outcome of in vitro fertilization and embryo transfer (IVF-ET) outcome.
abstract: BACKGROUND
  To evaluate the relationship between endometrial thickness on day of human chorionic gonadotrophin administration (hCG) and pregnancy outcome in a large number of consecutive in vitro fertilization and embryo transfer (IVF-ET) cycles.
  
  
  METHODS
  A retrospective cohort study including all patients who had IVF-ET from January 2003-December 2005 conducted at a tertiary center.
  
  
  RESULTS
  A total of 2464 cycles were analysed. Pregnancy rate (PR) was 35.8%. PR increased linearly (r = 0.864) from 29.4% among patients with a lining of less than or equal to 6 mm, to 44.4% among patients with a lining of greater than or equal to 17 mm. ROC showed that endometrial thickness is not a good predictor of PR, so a definite cut-off value could not be established (AUC = 0.55).
  
  
  CONCLUSIONS
  There is a positive linear relationship between the endometrial thickness measured on the day of hCG injection and PR, and is independent of other variables. Hence aiming for a thicker endometrium should be considered.
authors.affiliation: Department of Obstetrics and Gynecology, Reproductive Medicine, King Faisal Specialist Hospital and Research Centre Riyadh, Kingdom of Saudi Arabia. ahlamaag@yahoo.com
authors.forename: Ahlam
authors.initials: A
authors.lastname: Al-Ghamdi
authors.forename: Serdar
authors.initials: S
authors.lastname: Coskun
authors.forename: Saad
authors.initials: S
authors.lastname: Al-Hassan
authors.forename: Rafat
authors.initials: R
authors.lastname: Al-Rejjal
authors.forename: Khalid
authors.initials: K
authors.lastname: Awartani