Diagnostic performance of HyFoSy versus HSG for tubal patency: accuracy and agreement analysis

Tubal patency examination is an essential part of the infertility workup; hysterosalpingo-foam sonography (HyFoSy) is a recommended substitute for the standard hysterosalpingography (HSG). This study aimed to determine the diagnostic concordance of HyFoSy and HSG, as well as the impact of uterus position on test performance.

The prospective observational cohort study enrolled 80 infertile women referred for assessing tubal patency at Al Yarmouk Hospital. Recorded parameters included demographics (age, parity, uterus position) and the results of tubal patency testing (patent, unilateral, or bilateral blocked tubes). HyFoSy was performed first, followed by HSG.

Age and parity were insignificant. HyFoSy showed a high degree of diagnostic concordance with HSG (85%), with a Cohen's k coefficient of 0.3 (95% confidence interval, CI: 0.05-0.55). Gwet's agreement coefficient 1 was 0.84 (95%, CI: 0.74-0.94), indicating strong agreement. McNemar's test revealed significant systematic bias between the methods (p < 0.001), suggesting that HyFoSy and HSG are not interchangeable, which was further confirmed by Bland-Altman analysis showing a mean bias of +0.25 in favor of HyFoSy. The latter has a tendency to overestimate tubal patency among women with a retroverted uterus.

HyFoSy is a promising tool for use as a complementary infertility test, showing high concordance with HSG. However, it should not be used as a stand-in for HSG without clinical judgment, especially in women with a retroverted uterus. The best of both approaches may be provided by a hybrid strategy that uses HyFoSy as a first-line test and saves HSG for cases that are unclear or high-risk.