Methotrexate injection for interstitial pregnancy: Hysteroscopic conservative mini-invasive approach.

Background: Interstitial localisation of ectopic pregnancy is associated with high rates of maternal morbidity and mortality. Considering the rarity of interstitial pregnancy, the optimal treatment regimen remains unclear. We propose the management of interstitial pregnancy with local methotrexate injection using a combined hysteroscopic and ultrasonographic approach.

Technique: Hysteroscopy was performed under local anaesthesia in the operating room, using a 2.9-mm Hopkins II Forward-Oblique Telescope 30° endoscope with a 4.3-mm inner sheath and 5 FR instruments. A needle was pushed into the cornual region injecting methotrexate solution directly into the gestational sac and into the myometrial tissue tangentially at the four cardinal points. A contemporary transabdominal ultrasound (US) was performed in order to reduce risks of complications.

Experience: Five patients with an US diagnosis of interstitial ectopic pregnancy admitted to our department between January 2016 and September 2019 were managed with a local hysteroscopic injection of methotrexate. The technique was effective in all patients and no surgical complications occurred during or after the procedure. Three patients were evaluated for tubal patency with contrast ultrasonography confirming bilateral tubal patency 9 months from treatment, while one patient had a spontaneous birth 22 months from their initial surgery.

Conclusion: The hysteroscopic ultrasound-guided approach combined with the local injection of methotrexate is a minimally invasive conservative approach that seems to be promising in the management of interstitial ectopic pregnancy.