EP15.06: A case of abnormally invasive placentation in a nulliparous woman following uterine artery embolisation for uterine fibroids

Abstract

Abnormal placentation is typically associated with prior Caesarean delivery but other etiologies have been reported. Uterine artery embolisation is increasingly being performed for non-invasive treatment of uterine artery fibroids. The impact of this therapy on subsequent pregnancy outcome is unclear. We present a case of a 32 year old woman with a large multifibroid uterus and resultant heavy menstrual bleeding. The largest leiomyoma was posterofundal, extending through the entire myometrial thickness, and measuring 86 x 84 x 97 mm, with very little surrounding myometrium. She desired fertility preservation due to nulliparity and underwent uterine artery embolisation via interventional radiology. The procedure failed to cure her symptoms and she subsequently underwent laparotomy and myomectomy with successful removal of the leiomyoma. She conceived spontaneously a year later. Routine fetal anatomy survey at 18.6 weeks gestation demonstrated an extensive placental implantation with multiple large placental lacunae. As the pregnancy advanced, the lacunae increased in complexity and size, with high velocity blood flow seen swirling around the lacunae on Cine-loops and in B-Flow mode. The largest lacunae were 80 mm in diameter. It was noted that the myometrium was very thin at the site of the myomectomy. The woman's pregnancy course was complicated by gestational diabetes mellitus and pre-eclampsia. A Caesarean delivery was performed at 35.2 weeks gestation due to worsening pre-eclampsia. A live female infant weighing 2300g was delivered. The placenta was morbidly adherent. An emergent peripartum hysterectomy was performed with a 6000 mL blood loss. Histopathological studies of the placenta and uterus confirmed the diagnosis of placenta accreta with focal placenta increta. This case demonstrates the ultrasound signs of abnormally invasive placentation, and that pregnancy after arterial embolisation for leiomyomas may be associated with adverse pregnancy outcomes.