A breast pump comprises a body member ( 2 ) including a breast engaging portion ( 4 ) shaped to engage a region of a users breast, a container ( 32 ) attached to the body member ( 2 ), valve means ( 28 ) between the body member ( 2 ) and the container ( 32 ), and, within the body member ( 2 ), a sleeve ( 12 ) sealing the interior of the body member ( 2 ) from the atmosphere, the sleeve ( 12 ) being selectively movable from a rest condition to a displaced condition by actuating means ( 14 ) operatively connected to the sleeve ( 12 ), movement of the sleeve ( 12 ) from the rest condition to the displaced condition creating an increasing volume of reduced pressure within the body member ( 2 ) whereby firstly the valve means ( 28 ) is closed to prevent evacuation of the container ( 32 ), and whereby milk is expressed by the user into the body member ( 2 ), and return movement of the sleeve ( 12 ) from the displaced condition to the extended condition releasing the reduced pressure allowing the valve to open, the expressed milk flowing through the valve means ( 28 ) and into the container ( 32 ), the configuration of the sleeve ( 12 ) or the material of the sleeve ( 12 ) being such as to substantially prevent stretching of the sleeve ( 12 ) on movement between the rest and displaced conditions.
