Transvaginal three-dimensional ultrasound: Reproducibility of ovarian and endometrial volume measurements

Objective: To assess the reproducibility of ovarian and endometrial volume measurements obtained using transvaginal three-dimensional (3D) ultrasound (US). Design: Prospective clinical study. Setting : A tertiary referral center for assisted reproduction. Patients: Forty women undergoing ovarian stimulation for IVF-ET using the long protocol of GnRH agonist. Intervention: Three observers independently measured 20 stored ovarian scanned volumes and 20 endometrial volumes. Also, ovarian volume was calculated from three diameters obtained by two-dimensional (2D) US. Main Outcome Measure: Analysis of variance, the paired Student's t-test, and calculation of intraclass and interclass correlation coefficients were used for statistical analysis. Results: Three-dimensional ovarian volume measurements were not significantly different from ovarian volume calculated from three diameters (7.98 versus 7.58 mt). The mean endometrial volume measurement was 3.56 mt. The intraobserver coefficient of variation for both ovarian and endometrial volume was 8%. The interobserver coefficient of variation was 9% for ovarian volume and 11% for endometrial volume. Intraclass and interclass correlation coefficients were 0.95 and 0.95 for ovarian volume and 0.90 and 0.82, respectively, for endometrial volume. Conclusion: Transvaginal 3D US produces highly reproducible ovarian and endometrial volume measurements.