OXT and pulmonary arterial hypertension: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide, contributing to approximately 20% of total maternal deaths.1 The gold standard uterotonic agent, oxytocin, has been shown to reduce the risk of PPH by 50% and is recommended by the WHO for administration via intravenous or intramuscular injection to every woman during the third stage of labour for the prevention of PPH.2 3