While nipple thrush itself can’t affect your milk supply, the symptoms from it can make some women avoid breastfeeding because of the pain, thus negatively affecting their supply. “Since breast milk is usually produced based on supply and demand, if the demand is decreased then the supply will be decreased,” Keith explains. “It’s important for women to try and continue to breastfeed. If it’s too painful, you can try pumping.” If you do try pumping, be sure to wash and sterilize all materials used so that the equipment doesn’t end up reinfecting you down the line.