A hands-free breast pump system is disclosed. A breast shield having an adhesive inner surface for adhering to a woman's breast is disclosed. The breast shield may be connected to an adapter for transferring a vacuum generated by a pump to the breast. The adapter also allows milk expressed from the breast to drain from the adapter to a container. In the alternative, the breast shield may form part of a breast shield adapter system which is connected to a conventional breast shield by a drain line so that a conventional breast pump system is used to supply a vacuum and to collect the milk.