Written by Wendy, IBCLC.
If your baby has ever refused to drink your pumped breast milk, you know how stressful this can be. After all, you’ve worked hard to pump that milk, and you don’t want it to go to waste. Not only that, but usually, this happens when you are separated from your baby, and the idea of your baby fussing and not eating can make this separation all the more challenging.
Many parents wonder if the reason their baby has rejected their milk is because of a bad smell. Perhaps you’ve given your pumped milk a sniff test, and you notice that it has a soapy, metallic, or even rancid scent. When breast milk has an unpleasant odor, something called high lipase is often blamed. While high lipase content may be a cause of breast milk with a bad or sour smell, this isn’t always the case. Still, it’s a potential culprit to be aware of.
Here, we’ll go over everything you need to know about high lipase and breast milk, including how to know if it’s what’s causing your issue, how to manage it, and what to do if something else is causing your baby to reject your milk.
WHAT IS HIGH LIPASE?
Lipase is an enzyme that naturally occurs in breast milk. Its job is to break down fats in your breast milk. When triglycerides (a kind of fat) are broken down in breast milk by lipase, fatty acids are released. It’s theorized that when there is a high amount of lipid activity in breast milk, it may change the scent of breast milk. This scent is usually described as soapy, but it’s also been described as metallic or like milk that’s gone sour.
HOW DOES HIGH LIPASE IMPACT BREAST MILK?
As the Academy of Breastfeeding Medicine (ABM) points out, lipase activity in breast milk isn’t necessarily a bad thing, as it has antimicrobial impacts on breast milk—in other words, it decreases the overgrowth of microorganisms.
The Academy of American Pediatrics assures that even though high lipase milk may have an unpleasant odor and even an unpleasant taste, it’s not unhealthy for babies to drink. It doesn’t cause upset tummies, introduce unhealthy bacteria, or alter the nutritional content of the breast milk.
As the ABM notes, we lack evidence that points to babies flat-out rejecting pumped milk based on odor. The fact is, many babies have no problem with high lipase milk that smells bad—they just seem to go with the flow. You can be assured that it’s fine for these babies to drink it.
At the same time, some babies just don’t like the smell or taste of breast milk with high lipase … and this is where high lipase may become an issue.
HOW TO KNOW IF HIGH LIPASE IS THE PROBLEM?
Given that our young babies can’t articulate to us what is causing them to refuse our pumped milk, it’s important not to jump to conclusions that your baby is rejecting your pumped milk based on smell or odor alone.
Again, though, some babies really do seem to reject bad-smelling or tasting milk. So, how might you be able to tell if this is what’s going on with your little one? One method is to do some experimentation. The fact is that freshly pumped milk usually doesn’t have a bad smell—it’s only milk that has sat around for a period of time that will be affected by high lipase.
So, what you can do is give your baby freshly pumped milk a few times in a bottle—making sure it’s given by the same person, in the same location, at roughly the same time of day—and see how your baby reacts. Make sure you also smell the fresh milk and note how it smells.
Then, give your baby pumped milk that has been stored in the fridge or freezer and see how they react. If they refuse it—especially if you notice that it has an unpleasant odor—you might be able to assume that they are reacting to the scent or smell of the milk.
WHAT TO DO ABOUT HIGH LIPASE?
So, let’s say you have a baby who really seems to have trouble with the scent or odor of your milk. What can you do about it?
USE MILK AS SOON AS POSSIBLE
Fresh milk is less likely to have an unpleasant taste or odor than stored milk. So, the sooner you give your baby your milk, the better. Of course, it’s not always practical to give your baby freshly pumped milk when you are away. You can consider mixing fresh milk with your stored milk to decrease the likelihood of a poor smell or taste.
FREEZE YOUR MILK WELL
According to the ABM, the colder you freeze your milk, the less likely it is to have an alteration in taste or smell. So, this might mean storing milk further back in your freezer or adjusting the dial on the freezer to a colder setting. Moving refrigerated milk to the freezer as soon as possible—if you know you aren’t going to use it—can be helpful as well.
CONSIDER SCALDING YOUR MILK
Some mothers find that scalding pumped milk – heating it to just before it boils – can help neutralize the effects of lipase and decrease the bad odor or taste of the milk. The ABM recommends against scaling your milk because doing so can remove important immunological factors from the milk. The AAP says that although heating milk changes some of the biological qualities of the milk, it is sometimes better than having your baby reject your milk altogether. You can reach out to your pediatrician for advice about what to do in your individual case.
WHERE TO GO FROM HERE
It’s vital to keep in mind that babies reject pumped milk or bottle-fed milk for numerous reasons. Some babies just aren’t used to the bottle yet. Some babies may need a different bottle nipple or a different approach to bottle-feeding (check out paced bottle feeding for some helpful tips!). Other babies do better when being bottle-fed in different positions, different environments, or when the caregiver does a little skin-to-skin with the baby.
If you are having trouble getting your baby to drink your expressed milk, it can be a game-changer to work with a breastfeeding counselor or lactation consultant to help you figure out what is going on with your baby and to come up with an effective solution.
*This is not intended to be medical advice. Please consult with your healthcare provider.
