Baby Sleep Advice That Can Lower Your Milk Supply

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Wondering how to keep up your milk supply when baby sleeps through the night? Or perhaps you’re noticing that your milk supply has dropped after sleep training? Here’s what you need to know.

We all want sleep.

I don’t begrudge you your eight hours, I promise. And I understand what it feels like to miss the uninterrupted nights you took for granted before you had kids.


Worried your baby isn’t sleeping long enough? Our FREE guide will give you 10 baby sleep facts all parents need to know. Get some peace of mind about your baby’s sleep!

I also take it (given that you’re reading this) that you’re breastfeeding, and maybe even having milk supply issues, sleep frustrations, or both. So you should know:

There are a lot of different “tricks” out there to get your baby to sleep. But not all of them are developmentally appropriate at the ages “they” suggest you do them. None of them are actually guaranteed to get you sleep. And many of them can actually harm your milk supply.

Here is some common sleep advice you might want to take a critical look at if you are a breastfeeding parent:

Medical Disclaimer: The content of this blog post is not medical advice nor is it a substitute for medical advice, diagnosis, treatment, or professional lactation care. This post is for educational and informational purposes only. It is the reader’s responsibility to review all information regarding any medical condition or treatment with a healthcare provider.


First of all, there is simply no research to support that formula-fed babies sleep better than breastfed babies. Overall, they wake the same amount (source)!

Although formula-fed babies do tend wake a bit less frequently in the first few weeks, differences disappear quickly. Regardless of feeding style, research has shown both formula fed and breastfed babies get the same amount of sleep in a 24 hour period and are equally capable of developing sleep skills (source).

I know the prospect of there being even a chance that formula will help your baby sleep more soundly makes the idea of offering it tempting, especially when you’re tired.

However, infant sleep researchers hypothesize that this deep sleep early in life might make some babies more vulnerable to SIDS (source, source). In other words, a deep sleeping infant isn’t necessarily a desirable goal. Night-waking actually protects babies.

But if you’re breastfeeding, perhaps the biggest issue with offering formula at night is the significant impact it can have on your milk supply.

Mom feeding her young baby a bottle before bed. Sometimes this can cause low milk supply issues.

You’ve probably heard it said that milk production is a matter of supply and demand, and this is true (source). When your body detects demand–through nursing or pumping–your body continues to make milk. If the demand decreases, supply decreases.

When baby gets a bottle of formula at night, your body gets no signal (demand) that it needs to produce more milk. In order to protect your overall milk supply, especially if you are pumping for baby at work, you need to give your body this signal. In other words, you need to pump a full session (about 20 minutes typically) for every bottle of formula baby gets–at any time, day or night.

And this doesn’t only apply to formula bottles: Relying on a frozen milk “stash,” or offering a “top off” bottle of formula or breast milk before bed to promote sleep can also lower milk supply.

As you can imagine, pumping at night every time baby gets a bottle of formula or frozen breast milk is actually more work for you, not less. Not only do you need to sit there to pump, but now you have pump parts to sterilize and bottles to wash.

Mom washing bottle parts

Now if exclusive breastfeeding is not your goal, then this may not be a huge concern for you. You can combination feed if that’s what you’d like to do! Just be prepared for a decrease in milk supply, and remember that you’ll be making up for that decrease with formula.

What if you need to supplement? If you are needing to supplement, speak with a qualified lactation professional (usually an IBCLC, since most pediatricians have little to no lactation training) about how to protect your milk supply in the meantime. An IBCLC can help you build your supply so that supplementation is no longer necessary, or she can help you maintain your current supply so that you do not eventually need to transition exclusively to formula. Every situation will be unique.


This is problematic advice for several reasons, the first being that it is an outdated practice, one that is no longer recommended due to being a choking hazard (source).

The second reason has to do, once again, with your milk supply: Any food that baby gets without needing to stimulate the breast has the potential to lower your milk supply.

On top of that, most infant cereal has fewer calories, less fat and fewer vitamins and minerals than human breast milk anyway, so cereal would be filling up the valuable real estate of a baby’s tiny tummy with a food substance that is less nutritionally dense than breast milk. Not to even mention that there is no research to support that cereal actually helps babies sleep (source).

And finally, there is the issue of early solids. All major health organizations now recommend waiting to at least six months of age–no longer 4-6 months–before introducing foods other than breast milk or formula. If baby is older than 6 months of age, he or she doesn’t need to take cereal in a bottle. And if baby is younger than that, they probably shouldn’t be eating cereal period.

Did you know? It is no longer recommended to introduce solids at 4-6 months. Introducing solids too early can also result in low milk supply.


While it seems like a nice way to encourage “good” sleep habits, promote longer sleep stretches at night, and make your life a little simpler, feeding a breastfed baby on a schedule is not recommended by anyone who has really studied lactation.

Again, it all goes back to milk supply.

Breastfed babies are excellent at regulating their own milk intake, but they are also limited by a mother’s unique milk storage capacity.

To understand what I mean, it helps to think about a factory warehouse. A warehouse stores the items a factory produces. The factory workers will slow down and produce fewer items when they see the warehouse is running out of room to store them. If the factory workers empty out the warehouse every so often, the factory can resume producing items at a steady rate. If the warehouse size is small, it needs to be emptied out more often to make room for more product. If it’s a large warehouse, it can hold a lot more product before it needs to be emptied out again.

Your breasts work the same way: If her breasts are full, milk production slows down, and if they are emptied, more milk is made. If she has a small storage capacity, her breasts need to have milk removed more often to keep up production than if she had a larger storage capacity.

Milk storage capacity does not depend on how large or small a mom's breast are, nor is it related to how much or how little she can pump. The pump is not a reliable indicator of low milk supply or storage capacity.

Your milk storage capacity does not put a limit on the total volume of milk she is capable of making (small and large capacity breasts can produce the same volume of milk in a 24 hour period). And it does not have anything to do with your breast size (large breasts can have small storage capacity, and small breasts can have huge storage capacity) or how much she is able to pump (pump output is NOT a reliable indicator of supply or storage capacity).

The beauty of breastfeeding is that an otherwise healthy infant with a good latch, who is allowed to nurse on demand, will nurse exactly as often as they need to to maintain your milk supply long term.

When a baby naturally starts to sleep longer stretches, your body will regulate to meet baby’s demand and you won’t need to do anything special to do anything special at night to protect or promote supply.

The system runs on autopilot!

So this is how feeding schedules become problematic:

If a mother with a small storage capacity tries to get her baby on a feeding schedule, she might not be removing milk frequently enough to maintain her current rate of milk production over time.

The more immediate concern, however, is that baby may not have taken in enough milk at the last feed to get him to the next feed without being hungry.

Feeding on demand not only protects milk supply, but it keeps baby satisfied. Don’t forget–breast milk is easily and quickly digested, and breastfed babies simply need to eat frequently; this is especially true if you have a small storage capacity.

Stretching out time between nursing sessions–or nursing less often than whenever baby cues–in order to conform to an arbitrary feeding schedule can have a real impact on your milk supply.

New research has found that breastfeeding mothers who nurse according to a schedule nurse noticeably less frequently–closer to 6-8 times a day compared to around 10-12+ (source). So it’s not surprising, then, that mothers who follow parent-led schedules tend to quit breastfeeding sooner than mothers who don’t (source).

People who tell you parent-led schedules didn’t cause a supply issue either lucked out by having a large storage capacity (one not as easily affected by a schedule) or never nursed long enough for the issue to surface (think back-to-back pregnancies).

If your goal is to breastfeed the two years or more that the World Health Organization recommends, this issue with feeding schedules is worth noting.

Help! My supply is already low! What do I do? If you suspect you have low supply, speak with a lactation professional, usually an IBCLC, as soon as possible. Remember that milk production is a matter of supply and demand, so to increase supply the best course of action is to nurse and/or pump more frequently. In-person assistance may be needed and is always recommended.

Might be bad advice: “START SLEEP TRAINING”

If you’re a breastfeeding parent, most run-of-the-mill, traditional sleep training methods (think cry-it-out, graduated extinction, controlled crying, and other variations of the Ferber method, etc.), can be problematic if baby isn’t getting the chance to nurse as often as he or she needs to at night to maintain milk supply. Some people can make it work, while others–who may already be struggling to find time to pump while working or who may be dealing with latch or weight gain issues, for example–won’t be so lucky.

That said, I say that “start sleep training” might be bad advice because it really depends on what exactly is meant by sleep “training.” And some parents do genuinely need assistance with their baby’s sleep, so getting that assistance would be a good thing.

But if you don’t feel comfortable with traditional sleep training methods…where does that leave you? Are you doomed to perpetually sleepless nights?

No! Absolutely not.


Many of these techniques require more information than I can flesh out in a few paragraphs at the bottom of this article, so this topic will eventually get its own post. But until then…

Here’s What I Recommend:

I am extremely picky about sleep programs for babies. Because the truth is, many courses that are marketed as “gentle” still involve leaving baby to cry for periods of time. And many courses marketed as “breastfeeding friendly” still encourage night weaning by arbitrary ages and schedules that can interfere with on-demand nursing. So what do I recommend instead, you ask?

  • These courses by Lauren at Isla Grace. Her programs are attachment-focused and about as breastfeeding-friendly as they come.
  • These guides by Lyndsey Hookway. Lyndsey is an IBCLC and infant sleep expert who focuses on whole-family sleep solutions.
  • These books:


Worried your baby isn’t sleeping long enough? Our FREE guide will give you 10 baby sleep facts all parents need to know. Get some peace of mind about your baby’s sleep!

If you enjoyed this post, be sure to check out our digital library of helpful resources that quickly teach how to avoid common breastfeeding problems and give you the peace of mind and confidence you need to meet your breastfeeding goals.

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