Diagnostic Performance of Saline Infusion Sonography with Color Doppler Flow (SIS-CF) for Assessing Tubal Patency: A Prospective Cohort Study

Background/Objectives: Accurate evaluation of fallopian tube patency is an essential step in infertility assessment. This study investigated the diagnostic capability of saline infusion sonography combined with color Doppler flow (SIS-CF), using laparoscopic chromopertubation as the comparator method. Methods: A prospective diagnostic accuracy study was conducted between January and November 2025 at the Infertility Unit, Chiang Mai University Hospital, Thailand. Women requiring laparoscopic assessment for infertility evaluation or preconception investigation were consecutively enrolled. Each participant underwent SIS-CF immediately before laparoscopic chromopertubation within the same operative session. Primary outcomes included diagnostic indices for tubal patency. Secondary outcomes included procedural duration and perioperative safety. Results: Forty-four women (88 fallopian tubes) were included. SIS-CF demonstrated sensitivity of 89.4% (95% CI 78.1–95.9) and specificity of 95.5% (95% CI 77.2–99.9). Positive and negative predictive values were 98.3% and 75.0%, respectively. Likelihood ratios were 19.65 (positive) and 0.11 (negative), with overall accuracy of 90.9% (95% CI 82.9–95.8). Median procedure duration was 5.7 min for SIS-CF and 3.0 min for laparoscopic chromopertubation. No adverse events were recorded. Conclusions: SIS-CF demonstrated favorable diagnostic characteristics for evaluation of tubal patency. The technique provided functional information regarding tubal status while maintaining a minimally invasive profile. Further investigation is warranted to determine its role within routine infertility workups.