Nipple shields can be used by breastfeeding mothers to facilitate the feeding process. The disclosed embodiments relate to nipple shields with a port through which liquid supplement can flow from a supply tube into an interior section of the shield. The liquid supplement can be drawn through ports in a tip of the shield in order to augment a naturally expressed flow of milk. A flap of material is bonded to an interior portion of the nipple shield over an optional channel formed in the interior portion so as to form a closed, flap-covered channel leading from an input port on a lower portion of the shield to a an interior location near the tip of the shield.