A pressure regulating device (134) for use with a breathing assistance and/or resuscitation apparatus, the apparatus supplying gases over a flow rate range to an infant or neonate requiring resuscitation and/or breathing assistance, the pressure regulating device (134) comprising: a housing (300, 330) including an inlet (302, 328), a main outlet (304), and an external venting outlet (306, 332,334), the housing (300, 330) defining a flow path between the inlet (302, 328)and the main outlet (304), the inlet (302, 328) adapted to be in fluid communication or integrated with the breathing assistance and/or resuscitation apparatus and the main outlet (304) adapted to be in fluid communication with an infant. The pressure regulating device (134) also comprises an internal venting aperture between the inlet (302, 328) and the external venting outlet (306, 332,334), and a valve member (308) disposed within the housing (300, 330), between the external venting outlet (306, 332,334) and the internal venting aperture, so that when the pressure of gases in the flow path is below a predetermined level, the valve member (308) at least partially blocks the internal venting aperture (306, 332,334) and the gases flow from the inlet (302, 328) to the main outlet (304). When the pressure of the gases is above the predetermined level the valve member (308)opens to allow at least a portion of the gases to flow from the inlet (302, 328) through the internal venting aperture and the external venting outlet (304).
