Anomalous systemic arterial supply to the basal segment of the lung presenting with haemoptysis in the third trimester of pregnancy.

Anomalous systemic arterial supply to the basal segment of the lung (ABLL) is a rare cause of haemoptysis. ABLL may be complicated by massive haemoptysis, heart failure due to left-to-right shunt and infection. We describe a case of this condition presenting in the third trimester of pregnancy. Computed tomography chest angiogram confirmed the diagnosis. A multidisciplinary approach was necessary to determine treatment, which ultimately consisted of elective caesarean section at 36 weeks and 4 days' gestation, followed by transarterial embolisation 9 days postpartum.