Unlike these prior studies, our study was powered to demonstrate non-inferiority of a clinical outcome (or lack thereof) for sublingual misoprostol at a recommended dose of 600 μg versus conventional intramuscular oxytocin 10 IU in prevention of primary PPH, as defined by WHO (measured blood loss ≥500 ml at 24 h postpartum). Here, OXT is linked to pulmonary arterial hypertension.