Your milk probably feels like a pretty precious commodity and managing it can become a really important bookkeeping task. I generally try not to be wasteful, but I kind of took it to another level when it came to my milk. I didn’t want to lose a single drop! (Anyone else?) You are probably going to waste some milk along the way, but here are some of the routines and habits that I used to try to make sure that I was using everything at the proper times and in ways that minimized waste.

One of the first things to be aware of is the “shelf life” for your pumped milk.  Knowing this helps you make sure that you use your milk before it goes bad and that you don’t dump something that didn’t need to be dumped because you weren’t sure whether or not it had gone bad. Here are some guidelines that are generally recommended for healthy full term babies. Source: www.breastmilkguidelines.com

  • Freshly expressed milk can be stored:
    • At room temperature (60-77 F) – up to 4 hours
    • In the Refrigerator (39 F or less) – up to 3 days*
    • In the Freezer (0 F or less) – up to 6 months
  • Previously frozen milk can be stored:
    • At room temperature (60-77 F) – up to 2 hours
    • In the Refrigerator (39 F or less) – up to 24 hours
    • In the Freezer (0 F or less) – should not be put back in the freezer

*This recommendation seems to have changed in the last couple of years. It was 3-8 days when my girls were babies and drinking pumped milk. I don’t think I kept milk in the fridge for 8 days, but I definitely went past 3 days. I don’t want to advise against recommendations, but I do want to say my babies were just fine drinking 3-5 day old milk. Use that info as you will. 😉

Once you start pumping, you will need a storage system for your milk. I rarely had extra milk to deal with when I was back to work full-time, so most of that milk was stored in the fridge. Before I went back to work, though, I did try to build up a freezer stash. I started pumping once or twice a day when my babies were about a week old. My routine was to pump between nursing sessions when they were sleeping. Some people will pump for a bit at the end of a feeding or find another time window that works for them instead. Whatever works for you is great here. It’s not necessary to do this, but you will probably appreciate it later if you are able to get some milk in your freezer before you go back to work. I was glad to have my frozen stash because I had trouble pumping enough to keep up. (People will point out that breastfeeding is all supply and demand and if you are consistently dipping in to a frozen stash, your body doesn’t know the true demand, so will not supply enough. I understand this, but the advice related to this is usually to either pump more or “just send what you pumped.” I tried really hard to pump more and knowingly sending less milk than I knew my baby would need did not feel like a practical solution. It felt unfair to my baby and to her caregiver, so I did the best I could and gained some perspective while I was at it.) Another plus to starting to pump on maternity leave is that you will have some practice with your pump before you are adjusting to all of the other changes that come along with being back at work and leaving your baby. It’s one less thing to figure out when everything else feels new.

All of the milk that I was pumping in the early days was making its way to the freezer. I froze the milk in 4 oz aliquots in freezer bags that are made specifically for breast milk. If I didn’t have exactly 4 oz to freeze, I waited until my next pumping session to combine milk so that I could freeze that specific amount. (This was my standard bottle amount, so having it frozen in those volumes made it easier when it came time to thaw milk for use. One bag was one bottle.) I labeled every freezer bag with the date and laid them flat to freeze, so they were easier to store. I had a box in the freezer where all the milk was ordered by date. However you keep it in your freezer, it is helpful to have some system to keep track of where your oldest milk is to ensure you don’t lose track of something and pass the 6 month storage window. Once I was back to work, most of the milk that I was pumping was stored in the fridge and easily used for a daycare bottle within the 3 (to 8 back then) days that was recommended. I didn’t store this milk in freezer bags. I kept it stored in spare bottles that came with my pump. These were also labeled by date and organized in the fridge with oldest first. These habits kept my milk stored safely and organized so nothing passed its “best by” date.

The next thing to think about is how to prepare bottles and a schedule that keeps your milk use efficient. I kept a schedule where I nursed in the morning before I left for work and right when we got home at the end of the day. I also tried to go to the daycare on my lunch break to nurse. (I loved doing this – it was one less bottle to pump and it also was a nice way to get to know her daycare teachers better.) It took a little bit of trial and error to figure out how many bottles I needed to send and how much milk each one should have. If you are primarily breastfeeding when you are with your baby, it can be really hard to know how much your baby is actually eating. When I first went back to work, I sent a mixture of 2 oz and 4 oz bottles as we were trying to figure out the right amount to send. Eventually, I switched to all 4 oz bottles because if daycare gave her a 2 oz bottle she almost always wanted another 2 oz bottle right away. I continued to send 4 oz bottles for pretty much the rest of the time I was sending bottles to daycare (to a little past her first birthday). Don’t panic if you see older babies drinking 8 or 10 oz bottles. These are probably bottles of formula. The composition of breast milk changes as your baby gets older, so you probably won’t need to keep increasing the volume for your baby. Your baby may eat larger volumes less frequently or something different, so play around with this a bit and make sure that you communicate with your child care provider to figure out what works best. Until you figure it out, I would send more bottles with smaller volumes to try to avoid wasting milk. Our daycare had a policy that they could only keep a bottle of breast milk for an hour after warming it. It’s less sad to think about dumping a small bottle of milk than it is to think about dumping a big bottle of milk.

The last thing to figure out is what milk you should be using to fill all those bottles. I tried to send a combination of freshly pumped milk and previously frozen milk each day because I was trying to manage that the milk in the freezer should be used within 6 months and that the refrigerated milk should be used within 3-8 days. When I prepared the bottles, I labeled them in the order that I wanted them to be used. Occasionally we would bring a bottle home at the end of the day that she didn’t need or want. I wanted to be sure that if there was a bottle left over, it was one that we could still use. Any milk that came from the freezer was labeled “use first” because if those didn’t get used that day, they would have to be dumped. (Previously thawed milk should be used within 24 hours.) Any milk that had been pumped a few days prior was labeled “use second” and the freshest milk didn’t get a special label. That way, if there was a bottle left at the end of the day, I could send it back the following day – usually with an updated label to “use first’ or “use second.”

And, like I’ve talked about before, breastfeeding doesn’t have to be all or nothing. Whatever you are able to do is great. The main thing is to just feed your baby. Fed is always best!