Giant chorangiomas are uncommon yet frequently associated with adverse pregnancy outcomes. A 37-year-old female was referred due to findings of a placental mass during a second-trimester ultrasound. A fetal survey at 26 weeks revealed a 69×97×75 mm heterogenous placental tumor with two prominent feeding vessels. Her prenatal course was complicated by worsening polyhydramnios requiring amnioreduction, gestational diabetes, and transient severe ductal arch (DA) constriction. Placental pathology confirmed the diagnosis of giant chorioangioma following delivery at 36 weeks. To our knowledge, this represents the first case of DA constriction in the setting of a giant chorangioma.