Administration of oxytocin (IV/IM); ergometrine/methylergometrine or other fixed drug combination of oxytocin and ergometrine (IM); misoprostol (oral).The preferred drug for prevention of PPH is oxytocin (10 IU, IV/IM). If unavailable, give IM ergometrine/methylergometrine or the fixed drug combination of oxytocin and ergometrine, if not contraindicated. If IM or IV uterotonics are unavailable, give oral misoprostol (600 μg). The gene discussed is OXT; the disease is pulmonary arterial hypertension.