Use refrigerated, opened, ready-to-feed and prepared formula within 48
hours.
Don't leave bottles of formula out of the refrigerator for more than two
hours.
Throw away the formula left in the bottle after a feeding, since germs from
baby's saliva will multiply in the warm formula.
Refrigerate any formula saved from one day to the next.
Be very careful if you are using a microwave oven to warm formula. It's
better not to microwave. Because of uneven heating, hot spots develop. If you
do use the microwave, shake the bottle well before testing the temperature on
your wrist.
Avoid bottle propping, and don't let a baby fall asleep holding his own
bottle. He could choke or aspirate the formula into his lungs. Falling asleep
with a bottle allows the sugary formula to pool in the mouth, in contact with
teeth, causing dental caries. When bottle-feeding in the lying-down position,
formula may travel from the back of the baby's throat up through the eustachian
tube into the middle ear, causing ear infections. Remember, bottle-feeding,
like breastfeeding, is a social interaction, in addition to a method of
delivering nutrition. There should always be a person at both ends of the
bottle, and babies should go to sleep attached to a person, not a bottle.