Container and milk expression device comprising the same

A container for receiving milk being expressed by a mother, the container being at least partly delimited by a wall comprising a visually transmissive wall, the visually transmissive wall being arranged to be in sight of the mother while the container is being worn by the mother, wherein one or more discontinuities interrupt(s) uniform extension of at least one surface of the wall, the one or more discontinuities being integral to the wall, and provided at a defined height or heights relative to a milk-supporting base of the container, to indicate a fill level by visual inspection by the mother, while wearing the container, of the one or more discontinuities and milk received in the container, and wherein said at least one surface of the wall whose uniform extension is interrupted by the one or more discontinuities comprises an interior surface of the wall, which interior surface is contactable by the milk received in the container.