Tubal patency assessment using sequential transvaginal ultrasound and hysterosalpingo-foam sonography after methotrexate treatment for tubal pregnancy: a new approach to an old challenge

Abstract Research question To evaluate the efficacy of sequential 2D transvaginal ultrasound (US) and hysterosalpingo-foam sonography (HyFoSy) after methotrexate (MTX) treatment for tubal pregnancy among patients who desire a future pregnancy. Design A prospective trial was conducted between May 2019 and November 2020. Only patients who had a suspected tubal ectopic pregnancy diagnosed by US and treated by MTX were included. These patients underwent sequential transvaginal 2D-US assessment of the pelvic organs and a complementary HyFoSy for tubal patency. The primary outcome was tubal obstruction in the affected side. Results During a study period, a total of 360 women underwent sequential transvaginal 2D-US assessment of the pelvic organs and a complementary HyFoSy for tubal patency. Of them, 40 (11.1%) women fulfilling the inclusion criteria were enrolled. In 6/40 (15%), hydrosalpinx of the affected tube was found during the initial transvaginal US examination and were excluded from further investigation. In the remaining 34/40 (85%) patients, HyFoSy was performed. Tubal block was found in 10/34 (29.4%) the patients. Of these, 8/34 (23.5%) and 2/34 (5.9%) had a proximal block of the affected tube and bilateral proximal obstruction, respectively. HSG confirmed the tubal obstruction in all the affected cases. No procedure-related complications were documented. Conclusions In this preliminary study, almost every second woman who was treated by MTX for tubal pregnancy was diagnosed as having a tubal obstruction. We suggest that sequential transvaginal US and HyFoSy be part of the routine follow-up for these women, thus offering them timely referral to the appropriate specialist. This approach should be considered in clinical guidance addressing the follow-up of women with tubal pregnancy treated with MTX.