A neonate with umbilical arteriovenous malformation showing hemorrhagic shock from massive umbilical hemorrhage.

We describe herein the case of a 3-day-old male neonate with umbilical arteriovenous malformation showing umbilical hemorrhage. The patient was born after 38 weeks and 3 days of gestation with a birth weight of 2784 g. Sudden massive umbilical hemorrhage occurred on day 3. Cardiopulmonary arrest developed, but the patient was successfully rescued by immediate cardiopulmonary resuscitation. An umbilical venous catheter was inserted for blood access. However, umbilical hemorrhage continued and hemostasis was difficult. Congenital bleeding disorders were excluded based on laboratory findings. Ultrasonography on day 15 revealed a mass with rich blood supply directly under the umbilicus. Umbilical arteriovenous malformation was suspected from abdominal contrast-enhanced computed tomography on day 17. Excision of the arteriovenous malformation was performed on day 29. The mass was connected to three arteries including the umbilical arteries, with the umbilical vein flowing out from the mass. Umbilical arteriovenous malformation was diagnosed from evidence during the operation and pathological findings. Umbilical arteriovenous malformations are rare and often discovered by heart failure symptoms, but rare cases present with umbilical bleeding, as in this report. Umbilical arteriovenous malformation must be taken into consideration as along with congenital bleeding disorders when massive umbilical hemorrhage is identified. Thieme Medical Publishers.