To blind participants , the rule group simultaneously received intravenous oxytocin ( 3 IU/3 ml ) and a `` wide-open '' infusion of 0.9 % normal saline ( 500 ml ) ; the standard care group received intravenous 0.9 % normal saline ( 3 ml ) and a `` wide-open '' infusion of oxytocin ( 30 IU in 0.9 % normal saline/500 ml ) .