OXT and pulmonary arterial hypertension: According to the 2017 World Health Organization (WHO) guidance, treatment of PPH due to uterine atony consists of two major elements: first-response bundles, such as uterotonic drugs (mainly oxytocin), isotonic crystalloids, tranexamic acid (TXA), and uterine massage; and, if necessary, response to refractory PPH bundles, such as compressive measures (aortic compression or bimanual uterine compression), intrauterine balloon tamponade, and non-pneumatic anti-shock garment [9].