Diagnostic Accuracy of Hysterosalpingography Compared With Laparoscopy in Assessing Tubal Patency Among Subfertile Women: A Retrospective Cohort Study.

Background Fallopian tube pathology accounts for approximately one-third of female factor subfertility. The National Institute for Health and Care Excellence (NICE) Fertility Guidelines (CG156) recommend hysterosalpingography (HSG) as the first-line investigation for women without high-risk factors, such as pelvic inflammatory disease (PID), endometriosis, or prior pelvic surgery. However, its diagnostic accuracy varies with limitations, including tubal spasm and technical artefacts, and the contemporary data from the United Kingdom (UK) fertility services remain limited. This study evaluated the diagnostic accuracy of HSG compared with laparoscopy in detecting bilateral tubal blockage in a UK fertility clinic cohort. Methods We retrospectively reviewed 1,105 women aged 18-45 years who underwent HSG at NUH Life, Nottingham University Hospitals NHS Trust, UK, between January 2017 and July 2022 for subfertility (> 12 months). Exclusion criteria included BMI > 35 kg/m², incomplete records, recent PID, contrast allergy, or uncertain pregnancy status. HSG results were classified as bilateral blockage, unilateral blockage, or both tubes patent. Laparoscopy with dye testing was used as the reference standard and was offered to women with abnormal HSG tests or ongoing clinical indications. Fifty-three women underwent both procedures, of whom 49 women were included in the final analysis. Diagnostic accuracy calculations were performed using Statistical Product and Service Solutions (SPSS, version 31.0; IBM SPSS Statistics for Windows, Armonk, NY). Results HSG suggested tubal obstruction in 136 women (12.3%): 21 bilateral (1.9%) and 115 unilateral (10.4%). Laparoscopic correlation was available for 49 women. For bilateral tubal occlusion, HSG demonstrated a specificity of 94.3% (95% CI: 80.8%-99.3%) and sensitivity of 42.9% (95% CI: 17.7%-71.1%). For unilateral tubal occlusion, HSG demonstrated a specificity of 40.0% (95% CI: 23.9%-57.9%) and a sensitivity of 92.9% (95% CI: 66.1%-99.8%).  Conclusion In this large cohort, HSG demonstrated bilateral tubal patency in 955 women, avoiding laparoscopy in the first instance. HSG demonstrated high sensitivity for unilateral tubal occlusion and high specificity for bilateral tubal occlusion, which supports its role as an initial screening tool. Laparoscopy remains essential for confirmation of abnormal findings and for identifying additional pelvic pathology in patients with ongoing clinical concerns. Larger prospective multicentric studies are required to provide more precise estimates of diagnostic accuracy.