Objective: After the confirmation of an intact interstitial pregnancy through sonographic diagnosis and laparoscopy, systemic and local methotrexate therapy is a well established conservative treatment to preserve the uterus. The parameters of successful treatment are the course of serum hCG value and sonographic changes. In this case series we describe sonographic monitoring under methotrexate (MTX) application and the residual sonographic findings after completing therapy.
Methods: Three consecutive patients (two singleton and one twin pregnancy) with intact interstitial pregnancies were diagnosed and treated with MTX between 2000 and 2004. During the treatment we recorded the hCG values, maximum size of the interstitial lesion, vitality of the pregnancy, and vascularization.
Results: In all patients the sonographic diagnosis of an interstitial pregnancy was confirmed by laparoscopy. Following systemic MTX therapy, the hCG values normalised within 8 weeks in the singleton pregnancies and in 10 weeks in the twin pregnancy. During conservative therapy vascularization in the lesion withered continuously. The size of the primary myometrial lesion decreased at a slow rate and part of the lesion persisted in all three patients.
Conclusion: Despite decreasing hCG levels, residual sonographic patterns of an interstitial ectopic pregnancy persist in the uterine wall.