Pumping breast milk: the basics

Co-written by Deja Ramos, a Certified Doula (DONA), ICCE, and Co-Founder of The Birth Companions and Anna Morales, Co-founder of Mila Support

Whether you’re pumping occasionally, building a stash, or pumping full-time, the mechanics are the same and a little routine and know-how around storage makes it much less overwhelming. Here’s what to know about building a routine, and handling pumped (also called “expressed”) milk safely.

Building a routine

• A pumping session typically takes about 15-20 minutes, though this varies.

• If you’re building a stash, many people start a few weeks postpartum, once feeding is more established; if you’re preparing to return to work, starting a couple of weeks ahead gives you time to build a routine before you need it.

• Consider your baby's receptiveness to an artificial nipple if they have been exclusively breastfed from birth. 

• The recommended timeline is introducing a bottle between 4-6 weeks if there is a plan to use one in baby's first year. Even if it is just as a trial run.

• The most common pump fit issue is flange size. Pumps ship with the largest flange size as a "one size fits all" approach, but a flange that is too large is an ineffective "latch" and will not support efficient pumping for supply or storage. Getting professionally sized is a really good idea.

• An IBCLC or lactation counselor can help troubleshoot pump fit and settings, which make a real difference in both comfort and how much milk you’re able to pump.

Storing and handling breast milk safely

• Room temperature (77°F or colder): up to 4 hours.

• Refrigerator: up to 4 days.

• Freezer: about 6 months for best quality, up to 12 months acceptable.

• Store milk toward the back of the fridge or freezer, not the door, and label containers with the date. Leave a little space at the top of containers before freezing, since milk expands.

• Thaw the oldest milk first, thaw in the refrigerator or under lukewarm running water (never in the microwave), and use refrigerator-thawed milk within 24 hours. Once milk is warmed or brought to room temperature, use it within 2 hours, and never refreeze thawed milk.

• These timeframes are the guideline to go by, rather than a smell or taste test — breast milk doesn’t always announce spoilage the way other food does. One thing worth knowing so it doesn’t catch you off guard: some people’s milk naturally has more of an enzyme called lipase, which can make stored milk smell or taste soapy or metallic even when it’s completely fine to use. If your baby refuses stored milk and you suspect this, an IBCLC or lactation counselor can help you figure out a workaround.

Keeping your pump clean

A simple routine goes a long way: rinse pump parts that touch milk after each use, wash them with warm soapy water (or run them through the dishwasher if they’re labeled dishwasher-safe) at least once a day, and let them air dry. It’s also worth a quick check of your tubing now and then for any mold, and giving shared surfaces like dials a wipe if you’re using a shared or rented pump. Your pump’s manual will have any model-specific cleaning tips.

Note: a common misconception about pumps is the meaning of the term "hospital grade" - hospital grade does not assess the strength of the pumping action. It only confirms that milk passes through replaceable parts, so the machine can be used by different people.

Sourced from: CDC (Pumping Breast Milk; Breast Milk Storage and Preparation; Breast Pump Hygiene), Academy of Breastfeeding Medicine (Clinical Protocol #8: Human Milk Storage).