Transvaginal Sonography Post–Office Hysteroscopy as a Screening Tool for Tubal Patency: A Reliable and Feasible Technique in an Outpatient Setting

Objective: To determine feasibility and accuracy of post-hysteroscopic transvaginal ultrasonography (TVUS) measurement of pelvic fluid accumulation as a screening method for tubal patency (TP). Methods: We conducted a retrospective cohort study of 85 patients who underwent uterine cavity assessment by office hysteroscopy at our university-affiliated fertility centre from November 2019 to October 2020. During the study period, two-dimensional (2D) TVUS was performed pre- and post-hysteroscopy to evaluate TP. Patient records were reviewed for demographics, diagnosis, and prior/subsequent TP testing. Predictive values for TP were calculated. Results: Pelvic fluid accumulation post-hysteroscopy was found in 65.9% of patients (56). Accumulation of fluid was seen with the use of as little as 10–50 mL of saline. Using more fluid did not increase the likelihood of demonstrating TP (P = 0.17). A trend towards more false-negative results for TP was observed when less fluid was used (7.7% with 10–50 mL vs. 3.8% with 60–190 mL and 1.3% with 200–760 mL; P = 0.10). The positive predictive value (PPV) of TVUS post-hysteroscopy in comparison to known patency/occlusion was 100%; negative predictive value (NPV) was 33%; sensitivity was 82.8%; and specificity was 100%. Similar values were seen in a second analysis that included patients with highly suspected patent or occluded tubes (n = 60); presumed predictive values were: PPV 100%, NPV 42%, sensitivity 78.8%, and specificity 100%. The use of more fluid did not increase pain (P = 0.75). This finding remains after accounting for confounders (e.g., pre-medication, endometrial biopsy). Conclusion: TVUS pre- and post-hysteroscopy is feasible in an outpatient setting, and can serve as a reliable screening tool for TP. When hysteroscopy is performed and TP is not known, TVUS can be added for screening, potentially omitting the need for more invasive examinations. With limited non-urgent ambulatory services, it is of upmost importance to maximize information from a single procedure.