OP09.03: Intramural ectopic pregnancy: emerging from obscurity – an extended series

To evaluate clinical and sonographic characteristics of intramural pregnancy (IMP), as well as treatment outcomes. This was a retrospective cohort study of consecutive women diagnosed with an IMP between 2008-2024. An IMP was diagnosed on ultrasound if the pregnancy was implanted within the uterine corpus above the level of the internal cervical os, was separate from the interstitial section of the fallopian tube and breached the decidual–myometrial junction. Clinical, sonographic, and treatment outcomes were analysed. A total of 21 patients diagnosed with IMP were included in this study; 9 (43%) had partial and 12 (57%) complete IMP. Median gestational age was 8+1 (range, 5+5-12+0) weeks. In 13/21 (62%) the pregnancy was implanted close to the interstitial portion of the fallopian tube, in 9 cases below and in 3 cases above, and in the remaining case it was unclear due to severe anatomical distortion. 8/21 (38%) had a live IMP. Four patients (19%) had no identifiable risk factors for IMP, the remaining 81% had previous uterine surgery or concomitant uterine pathology. Over half were initially managed conservatively [12/21 (57%)], with 10/21 (48%) having expectant management, 1/21 (5%) having local methotrexate and 1/21 (5%) undergoing embryocide. In most cases conservative management was successful [11/12 (92%)] with median hCG resolution time of 71 (range, 35–143) days and median pregnancy resolution time of 303 (range, 63-535) days. One patient continuing pregnancy required emergency hysterectomy at 20 weeks' gestation for major blood loss. The remaining 9/21 (43%) cases had primary surgical treatment, predominantly transcervical suction curettage [7/9 (78%)]. However, two patients presented with uterine rupture and required emergency laparoscopy. Diagnosis of IMP can be challenging, but if diagnosed early, most patients will have good clinical outcomes with gestation, site and clinical presentation determining conservative or surgical management options. Conservative management is effective but is associated with prolonged resolution times.