You can begin pumping immediately, although if your baby is healthy and eating normally, you might wait until your supply has regulated before starting to pump. If you plan to return to work, start pumping about two weeks before your first day back.
Come into the cold
Pumped milk can be stored in bags, bottles or other fridge- and freezer-approved containers. Be sure that you wash your hands before transferring milk from one vessel to another, and label the milk with the date it was pumped.
It’s a date
Breast milk can be saved up to six hours at room temperature, five days in the refrig- erator, and up to six months in the freezer. Once you’ve thawed frozen milk, it’s good at room temperature for up to four hours and should not be refrozen.
Mix it up
Don’t worry if your milk separates while stored; it’s normal for cream to rise to the top. To blend the layers, simply swirl the bottle once the milk has been warmed. (To bring milk to body temperature, hold it under running water or place in a bowl of warm water for 20 minutes.)
Tip: It’s safe to add breast milk to the same refrigerated container throughout the day, according to the experts at Medela (medelabreastfeedingus.com). The key is to let the milk cool before pouring it in—you don’t want to add warm milk to already cooled milk.