The mean total dose of oxytocin received during labor was significantly greater among PPH cases than among the controls 1.52 +/− 0.04 and 0.95 +/− 0.06 UI, p <0.01 for Kruskall Wallis test); and greater among induced women than in women with spontaneous onset of labor, among both cases (3.05 +/− 0.09 and 1.10 +/− 0.03 UI respectively, p<0.01 for Kruskall Wallis test) and controls (2.04 +/− 0.13 and 0.71 +/− 0.13 UI respectively, p<0.01 for Kruskall Wallis test). Here, OXT is linked to pulmonary arterial hypertension.