Can hysterosalpingo foam sonography (HyFoSy) replace hysterosalpingography (HSG) as first choice tubal patency test: a randomized comparison (foam study)?

Abstract

Objective: Traditionally, tubal patency testing during fertility work‐up is performed by hysterosalpingography (HSG). Hysterosalpingo‐foam‐sonography (HyFoSy) is an alternative technique without radiation exposure and is less expensive than HSG. Globally, there is a shift towards the use of office‐based diagnostic methods, such as HyFoSy. Here, we assess whether HyFoSy is as accurate as HSG in evaluating tubal patency and if it leads to comparable pregnancy outcomes. Design: Multicenter prospective comparative study with a randomized non‐inferiority design. Materials and Methods: Participating women underwent both HyFoSy and HSG, in randomized order, by a physician unaware of the result of the first test (NTR 4746). In case of discordant results for HyFoSy/HSG, women were randomly allocated to either a management strategy based on HyFoSy or one based on HSG. Assuming 7% discordant results, we needed to recruit 1,163 participants (van Rijswijk et al., 2018). Primary outcome is ongoing pregnancy within 12‐months after inclusion. Secondary outcomes are concordance between HSG and HyFoSy, pain scores, live birth, time to pregnancy, clinical pregnancy, miscarriage, multiple pregnancy, preterm birth. Results: Between June 2015 and January 2019, a total of 1164 women were scheduled to undergo HSG and HyFoSy. At moment of writing, data on 97% was available. 2.3% of the women did not undergo any tests, 5.0% had HSG only and 0.6% had HyFoSy only. From the women who had both tests, 2.9% had an inconclusive HSG and 8.5% had an inconclusive HyFoSy (RR 2.3, 95%CI 1.6‐3.2). In 0.8%, both tests were inconclusive. Among the women with two tests completed, 85% had concordant results (94.7% patent tubes, 3% with unilateral occlusion, 0.9% with bilateral occlusion, 1.4% with other findings). The mean pain score on the 1‐10 VAS‐scale was 5.4 (95%CI 5.2‐5.6) for HSG compared to 3.0 (95%CI 2.9‐3.2) for HyFoSy (p‐value<0.001). Pain score of HyFoSy was not affected by the order of the tests (p=0.34). Of the 136 eligible women with discordant results, 108 women gave consent to be randomly allocated to management based on HSG (n=53) or HyFoSy (n=55). At moment of writing, data on the primary outcome were available in 58.5% of the HSG‐group versus in 54.6% of the HyFoSy group. Ongoing pregnancy occurred in 30.2% of the women allocated to management based on HSG, and in 27.3% of the women allocated to HyFoSy (RR 1.1, 95% CI 0.6–2.1). By October 2019, 90% of women will have complete one year follow‐up. Conclusions: HyFoSy and HSG have a concordance of 85%, with HyFoSy experienced as significantly less painful and without the need of radiation exposure. In case of a discordant result, management based on the results of HyFoSy or based on the results of HSG lead to similar pregnancy outcomes. Reference: van Rijswijk J, van Welie N, Dreyer K, van Hooff MHA, de Bruin JP, Verhoeve HR, et al. The FOAM study: is Hysterosalpingo foam sonography (HyFoSy) a cost‐effective alternative for hysterosalpingography (HSG) in assessing tubal patency in subfertile women? Study protocol for a randomized controlled trial. BMC women's health. 2018;18(1):64.