Microwaves heat unevenly. A bottle can feel lukewarm outside while the milk inside has hot spots that scald a baby.
The CDC, the FDA and the American Academy of Pediatrics all advise against warming infant milk or formula in the microwave, because of the uneven heating and the risk of burns. Warming the bottle in a bowl of warm water is the standard method.
| Short answer | No |
|---|---|
| Why | Uneven heating and hot spots that scald |
| Also | Official advice covers breast milk and formula alike |
| Safe method | Warm water bath or a bottle warmer |
| Test | Shake and put a few drops on your inner wrist |
How to warm a bottle safely
- Place the sealed bottle in a bowl or pan of warm, not boiling, water.
- Leave it for a few minutes, or use a bottle warmer.
- Swirl to mix the milk without making bubbles.
- Test a few drops on your inner wrist, which should feel warm and not hot.
- Use the milk straight away and discard what is left after the feed.
What happens when you get it wrong
- Scalding. Hot pockets in the milk burn a baby mouth while the bottle feels fine.
- Pressure. A tightly capped bottle can build pressure when heated.
- Damaged milk. Overheating can damage the milk, which is one reason the American Academy of Pediatrics advises against it.
A bowl of warm water, which heats evenly and gently.
A bottle warmer, if you feed often.
Frequently asked questions
Can you microwave breast milk?
Health agencies advise against it, because of hot spots that can burn a baby and because overheating can damage the milk.
Can you microwave formula?
Not recommended. Warm it in a water bath and test it.
Do you need to warm milk at all?
No. Babies can drink milk at room temperature or cool, if they accept it.
Can you microwave a sterilizing bag?
Some steam sterilizer bags are made for it. Follow the maker, and never put a bottle with milk in.