P35.02: Arteriovenous malformation of the uterus: successful pregnancy after medical treatment

Abstract

Uterine arteriovenous malformation (AVM) is a rare condition. Color Doppler ultrasound examination has been used to diagnose AVM prior to surgery in order to avoid dilation and curettage and the eventual worsening of the bleeding. Pregnancy following medical treatment of uterine AVM is rarely described. A 23-year-old woman, gravida 1, para 0, presented with a sudden massive vaginal bleeding. She reported regular menstrual cycles and had been on oral contraception for the last three years. In the recent past medical history she referred to a curettage for vaginal bleeding two months earlier. The transvaginal ultrasound examination showed a 13 mm anechoic non homogeneous, multilocular mass in the posterior right myometrium, beneath the endometrium. The color Doppler examination showed a large amount of turbulent arterial blood flow within the mass. Magnetic resonance confirmed the hypothesis of an AVM within the posterior subendometrial uterine wall. The patient was treated with intravenous conjugated estrogens and oral metilergometrine maleate. The bleeding regressed on the fourth day of therapy. The patient conceived eight months later. The pregnancy progressed uneventfully to term. The patient was admitted for elective Cesarean section at 39 weeks of gestation because of breech presentation of the fetus. The intraoperative examination of the uterus was normal. It is plausible that the transient vascular malformation was caused by trauma of the latest curettage. The case described showed a normalization of Doppler parameters in uterine vessels: it corresponded to the resolution of symptoms. We hypothesize that methylergonovine maleate induces a strong titanic contraction on myometrium and reduces the blood flow to the AVM making it collapse. To our knowledge this is the first report that describes the addition of high doses of intravenous conjugated estrogens, that can be helpful by covering exposed hemorrhagic vases with proliferative endometrium.