A breast pump assembly is provided having a housing that is hermetically sealed to define a chamber within the housing, a pump disposed within the housing, wherein the pump is in fluid communication with the chamber and with an atmosphere outside the housing, and a valve system having a first, second, and third port, wherein the first port is in fluid communication with the atmosphere outside the housing, the second port is in fluid communication with the chamber within the housing, and the third port is configured to connect to a pumping kit such that the third port is in fluid communication with the pumping kit.
