Interstitial pregnancy management: A multicentric analysis of 98 patients from the FRANCOGENT group comparing surgery and medical treatment

Objective: To evaluate the outcomes associated with each therapeutic option for patients diagnosed with interstitial pregnancy (IP). Methods: We conducted a multicentric retrospective cohort study within the departments of Gynecology and Obstetrics involved in the Francogent research group. Women treated for an interstitial pregnancy between January 2008 to December 2019 were included. Three therapeutic options were evaluated: surgical treatment (ST); in situ methotrexate combined with systemic methotrexate (IS-MTX); and systemic methotrexate (IM-MTX). Success of first-line treatment was defined by hCG negativation (<5I U/L). Secondary outcomes included the need for secondary surgical procedure, secondary medical treatment, emergency surgery, postoperative complications, duration of hospitalization, and delay before hCG negativation. Results: A total of 98 patients were managed for IP: 42 (42.9%) patients had IM-MTX; 34 (34.7%) had IS-MTX; and 22 (22.4%) had ST. First-line treatment was successful in all patients of the ST group (22/22, 100%), in 31% of patients within the IM-MTX group (13/42) and 70.6% (24/34) in the IS-MTX group. The sole parameter associated with the risk of treatment failure was the mode of methotrexate administration. The size of the gestational sac or the presence of fetal heartbeat was not associated with decreased medical treatment (IS or IM–MTX) efficiency. Conclusion: Either ST or IS-MTX are good options for IP treatment associated with high success rates. A single-dose regimen of IM-MTX is less efficient than IS-MTX or ST. Symptomatic patients with severity criteria should always undergo emergency surgery. IP remains a high-risk condition that should be managed, whenever possible, in referral centers to potentialize the chances of favorable outcomes.