Detection of hysteroscopic fluid in the pouch of Douglas: a prospective cohort study about the predictability of bilateral tubal occlusion

PURPOSE: To determine whether an increase in cul de sac (CDS) fluid after hysteroscopy is predictive of tubal patency. METHODS: In a prospective clinical cohort study, 115 subfertile women undergoing laparoscopic and hysteroscopic surgery at the Medical University of Vienna were invited to participate. The primary outcome was determining whether an increase in fluid in the pouch of Douglas was reflective of unilateral or bilateral tubal patency. Vaginal sonography before and after hysteroscopy was performed to detect fluid in the pouch of Douglas, directly followed by laparoscopy with chromopertubation. RESULTS: Laparoscopic chromopertubation revealed bilateral Fallopian tube occlusion in 28 women (24.3%). Twenty-seven/40 patients (67.5%) with no fluid shift had bilateral occlusion during the consecutive laparoscopy (p < 0.001). One/75 patients (1.3%) showing a fluid shift had bilateral occlusion (sensitivity of a present fluid shift for uni- or bilateral patency 85.1%, 95% CI: 81.7–99.9, specificity: 96.4%, 95% CI: 75.8–91.8). Intracavitary abnormalities (odds ratio, OR, 0.038; p = 0.030) and adhesions covering one or both tubes (OR 0.076; p = 0.041) increased the risk for a false abnormal result, i.e., uni- or bilateral tubal patency despite the lack of a fluid shift. CONCLUSION: When CDS fluid does not change after hysteroscopy, this is a sensitive test for tubal occlusion and further testing may be warranted. However, if there is an increase in CDS fluid after hysteroscopy, particularly for a patient without fluid present prior, this is both sensitive and specific for unilateral or bilateral tubal patency.