title: Prospective cohort study of three- versus two-dimensional ultrasound for prediction of oocyte maturity.
abstract: OBJECTIVE
  To determine whether three-dimensional follicular ultrasound (3-D) measurements are better predictors of optimal timing of hCG administration than two-dimensional (2-D) images, the current standard.
  
  
  METHODS
  Prospective, cohort study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Seventy-six patients undergoing IVF.
  
  
  METHODS
  Seventy-six consecutive patients undergoing serial follicular monitoring during IVF had an additional daily 3-D volume scan of their ovaries once lead follicles had reached 16 mm diameter.
  
  
  METHODS
  Number of mature oocytes retrieved.
  
  
  RESULTS
  The 2-D follicular diameter measurements predicted 25.4% of the observed variance in the number of mature oocytes retrieved. The 3-D follicular volume measurements were more predictive of outcome, accounting for 29.2% of the observed variance in number of mature oocytes retrieved. Follicles >22 mm diameter and 5 mL volume were associated with fewer mature oocytes reflecting an undesired postmature state. Follicles measuring 11 to 15 mm had a 50% chance of yielding a mature oocyte.
  
  
  CONCLUSIONS
  Three-dimensional follicular volume measurements have a stronger correlation with the number of mature oocytes retrieved than 2-D measurements. As 3-D technology improves, this parameter may replace 2-D measurements in the optimal timing of hCG before oocyte retrieval.
authors.affiliation: Department of Obstetrics and Gynecology, Hamilton Health Sciences Corporation and McMaster University, Hamilton, Ontario, Canada.
authors.forename: Doron
authors.initials: D
authors.lastname: Shmorgun
authors.forename: Edward
authors.initials: E
authors.lastname: Hughes
authors.forename: Patrick
authors.initials: P
authors.lastname: Mohide
authors.forename: Robin
authors.initials: R
authors.lastname: Roberts
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000592:standards; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000592:standards; D009865:Oocytes / Q000000981:diagnostic imaging* / Q000254:growth & development*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014463:Ultrasonography; D055815:Young Adult