Accuracy of Ultrasound in Estimating Uterine Fibroid Size: A Correlative Study With Intraoperative Findings.

Background Uterine fibroids are the most common benign tumors of the female reproductive tract and frequently require surgical management. Accurate preoperative estimation of fibroid size is essential for selecting the optimal surgical approach, anticipating operative complexity, and improving surgical outcomes. Ultrasonography remains the most widely used first-line imaging modality because of its accessibility, cost-effectiveness, and noninvasive nature. However, its ability to accurately reflect true intraoperative fibroid size may vary. Objective To evaluate the accuracy of preoperative ultrasonography in estimating uterine fibroid size by comparing ultrasonographic measurements with intraoperative findings. Materials and methods This prospective observational correlational study included women diagnosed with uterine fibroids who were scheduled for elective myomectomy or hysterectomy at a tertiary care center. The maximum diameter of the dominant fibroid measured on preoperative ultrasonography was compared with the corresponding intraoperative measurement, which served as the reference standard. Statistical analysis included the paired t-test, Pearson's correlation coefficient, intraclass correlation coefficient (ICC), Bland-Altman analysis, and subgroup analysis according to fibroid size and type. Results Eighty participants with complete paired measurements were included in the analysis. The mean ultrasonographic fibroid diameter was 5.20 ± 2.10 cm, compared with an intraoperative diameter of 5.52 ± 2.18 cm. Ultrasonography underestimated fibroid size by a mean of 0.32 ± 0.88 cm. This difference was statistically significant (t(79) = -3.25, p = 0.0017), with a 95% confidence interval (CI) ranging from -0.52 to -0.12 cm. Ultrasonographic and intraoperative measurements demonstrated strong positive correlation and excellent agreement. Overall, 62 (77.5%) participants had ultrasonographic measurements within ±1 cm of the intraoperative measurement. Greater measurement discrepancies were observed among intramural fibroids. Conclusion Preoperative ultrasonography demonstrated strong correlation and excellent agreement with intraoperative measurements of uterine fibroid size. Although it showed a small but statistically significant tendency to underestimate fibroid size, particularly in intramural fibroids, ultrasonography remains a reliable first-line imaging modality for routine preoperative assessment. Awareness of its limitations may facilitate more accurate surgical planning, and supplementary imaging may be considered in selected complex cases.