Preoperative Endovaginal Sonographic Diagnosis of an Unruptured Interstitial Pregnancy

Interstitial pregnancies carry a higher maternal morbidity and mortality rate, due to the abundant ovarian and uterine arterial supply of this region, than do other tubal pregnancies. Prerupture diagnosis is crucial, inasmuch as rupture (which usually occurs at a later stage than in tubal gestations) may be followed by rapid exsanguination. Precise early diagnosis may permit conservative nonsurgical treatment with methotrexate. A case is presented in which preoperative diagnosis of an unruptured interstitial pregnancy was aided by endovaginal sonographic examination. Considerations of subsequent management are discussed.