How to prepare breast milk expressed with Philips Avent? You can feed your baby breast milk from Philips Avent bottles and storage cups. Find out how to prepare expressed milk for your baby. Step-by-step instructions If you use frozen breast milk, let it defrost completely before you heat it. Note: In case of an emergency, you can defrost the milk in a bowl of hot water. Heat the bottle or storage cup with defrosted or refrigerated breast milk in a bowl of hot water or in a bottle warmer. Remove the screw ring and sealing disc from the bottle or remove the lid from the storage cup. If you are using a storage cup, screw the adapter ring onto the cup. Screw a sterilised screw ring with sterilised teat onto the bottle or onto the storage cup with adapter ring. Check the temperature Always check the temperature of the milk before you feed it to your baby and always discard any breast milk that is left over at the end of a feed. No microwave Never heat breast milk in a microwave, as this can cause uneven heating, which can lead to hot spots in the milk. It may also destroy nutrients in the milk.