Why sleep training and breastfeeding don’t mix (and what to do instead)

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I want to talk about sleep training/sleep programs/sleep methods for a bit… sorry, this is going to be long. And possibly rant-y. I’ll put a tl;dr at the end. 

I know many of you parents with young babies are bombarded by Instagram and Facebook ads for different baby sleep “programs”…

 or you’re learned about a sleep expert on the internet who has a plan to “teach” your baby to sleep twelve hours a night by the time they’re twelve weeks old…

or your friends gave you sleep training before your baby was born…

 or your boss or co-worker swears by a certain sleep method. 

Sleep is a big deal when you've got a baby. I get it. I really do.

Before I was an IBCLC (International Board Certified Lactation Consultant) I worked full-time while all three of my kids were breastfeeding. My commute was one hour each way. I was always exhausted. I know how much your baby’s sleep can make or break your day.

I have been there. I do not blame ANY parent for needing or wanting more sleep, ever.  Particularly in the USA where you’re expected to go back to work when your baby is 12 weeks old (or even sooner).

I know that sleep is vital to your ability to be a good parent.  I even took a very long and comprehensive Infant Sleep Education course to learn more about the science of sleep so I could help my clients get through the exhaustion.


If you’re exclusively breastfeeding and/or pumping for a baby under six months many of the current sleep “programs” or sleep “methods” that promise your baby will sleep 8-12 hour stretches can do more harm than good.

First, let’s go over something that isn’t well explained to most parents.  The typical 2 month old breastfeeding baby wakes up to eat every 2-3 hours overnight.  Once they’re around 4 months old, they are still usually waking twice a night to eat.  This is what keeps the milk factory chugging along nicely. 

Your body and milk supply are made to operate with frequent, consistent milk removals. This is how you keep a "full milk supply" when your baby is exclusively breastmilk fed.

MOST of the time you need at least 8 milk removals a day in the early months to maintain a full milk supply- and that needs to be pretty consistently spaced over the 24 hours.  That’s every 3ish hours, around the clock.  

frequent even milk removals, for example breastfeeding or pumping, keep your milk supply steady

For example: you can’t nurse once an hour between noon and 8 PM and then not nurse at all from 8 PM to noon the next day and continue to make a full milk supply (and also your baby will be really, really mad).  

So usually this comes out to some shorter 2 hour stretches or even cluster feeds during the day or in the evening/”witching hour” and (if you’re lucky) some 4 hour stretches overnight and it all works.


Once you start having consistent stretches of 5 hours or more without nursing or pumping your body is likely to make less milk.  Your milk supply can drop; sometimes just a little, sometimes a lot.

infrequent milk removals or consistent stretches longer than 5 hours without removing milk can cause your milk supply to drop


These longer stretches are a big part of what makes your body say “woah, this baby must be older to sleep so long- let’s get fertility back.” (here’s info from the CDC for more on how frequent breastfeeding can be good birth control, called the Lactational Amenorrhea Method or LAM, if you follow the rules). 

 If your baby is older when this happens, and already eating high quality solids as well as breastmilk, this is exactly what happens naturally!  Your body stops focusing on making a full milk supply and starts focusing on how to make a new baby. 

If your milk supply drops around month 3, you often aren’t aware of it.  Often in the USA babies see their pediatrician at 2 months of age and then not again until 4 months, so nobody is paying attention to baby’s weight in this two month span.

At 4 months, if there’s a big drop in weight percentiles, the first thing lactation consultants ask is if the baby is sleeping “through the night”.  We see this scenario play out over and over!

Below are the World Health Organization (WHO) weight charts for real babies who stopped gaining weight well during and after sleep training.  The pink arrow points out when they began their “training” or “method”.

Often times in these cases the parents are told that their milk isn’t high enough in calories or fat for their baby, or their baby needs to start solids immediately to gain weight, or lots of other things that don’t actually get to the cause of the problem.

Babies don’t always nurse more when they need more milk.  Depending on the personality of your baby they may be totally happy but their weight gain slows, or stops. I have even seen babies LOSE weight after being sleep trained.

And even if your milk supply does stay consistent (and sometimes it does!) there’s another problem.

Many of these sleep methods/trainings/programs recommend you only feed your baby 4 times a day- but babies who are eating breastmilk digest it so fast, and they eat small amounts close together.

Babies eating breastmilk generally eat small servings, so to get what they need to grow and flourish they are typically feeding 8ish times per day.  That lines up very nicely with how many milk removals you need in a day to keep up your supply.

So it’s very, very hard- nearly impossible- for babies to get the calories they need if they’re exclusively eating breastmilk and they are only eating 4 times per day. That would be 8 ounce bottles- and most babies eating breastmilk only ever eat 3-4 oz per serving!  

The majority of exclusively breastfeeding or exclusively breastmilk fed babies under six months old eat every 3ish hours with maybe one or two longer stretches overnight. They can't safely go 8-12 hours without eating.

Lots and lots of the “sleep programs” out there right now are hyper focused on the baby sleeping 8-12 hour stretches by 12 weeks of age. You’ll see that these programs almost always say they “work for breastfeeding moms, too.”

Emphasis on the “too”.

That’s because these sleep programs were NOT made for exclusively breastmilk fed babies; they’re made for formula fed babies (because if you control how much baby eats and when they eat you can sometimes make sure they get all 30 oz a day in those 12 hours they’re awake).

Although to be fair, I have also seen plenty of formula fed babies who stop gaining weight well after sleep training.  


There are tons of products out there on the market right now that can cause babies to sleep through hunger cues. For example when a baby is strapped to a bassinet, with motion and sounds and a bag of rice on their chest, their feeding reflexes are dampened.

Getting babies to sleep flat on their backs is tricky!  Companies jump through tons of hoops and sell a billionty products made to try to convince your baby to stay asleep.

Just because you can sometimes make a very young baby sleep 8-12 hours in a row doesn't mean it's good for them.

I see so many babies around 3-4 months who were “taught” to sleep 8-12 hours straight- and that baby is now having weight gain problems.

These babies can:

  • Gain weight much more slowly, so they fall off their growth curve
  • Stop gaining weight at all
  • Lose weight

Usually the family books a visit with me in a panic after the 4 month pediatrician appointment when they realize their baby isn’t gaining well any more and their supply has dropped, which we may or may not be able to fix.

Back to Work Pumping Planning Sheet

Headed back to work? Take the guesswork out of making milk for your baby while you’re separated.

Many of the popular programs can provide really helpful information about taking care of your baby, but please please PLEASE use your critical thinking skills about how and when they tell you to feed your baby, particularly for babies under six months who are only eating breastmilk. 

Take the good from the program, and leave the rest.

Here’s what I tell the families I work with. I recommend that babies under six months who are eating exclusively breastmilk shouldn’t go longer than five hours overnight without eating.  

What if your baby sleeps these long stretches all on their own, without you doing any sort of training or method?  After all, sometimes they do! 

Congratulations and enjoy your unicorn baby!  I recommend you grab baby and do a dream feed (if possible) OR do a pump session after five hours so you don’t have such a long stretch between milk removals.

This is the BEST way to protect your milk supply if your baby is sleeping very long stretches. If your supply is chugging along well you can begin to move this dream feed or pump session later and later- making the space between milk removals longer- and see what happens.  If your supply drops it’s easy to just go back to what you were doing.

Yes, this means you will still need to get up overnight.  You won’t be getting “a full night’s sleep” of one eight hour stretch.

So... we're back to where we started then. Sleep is a big deal. How do you get more?

Generally my favorite baby sleep advice is to change your focus.  Instead of aiming to get your baby to sleep as long a chunk of time as possible, I want you to aim to get yourself back to sleep as soon as possible when baby wakes up. Two or three overnight feedings aren’t terrible if your baby goes right back to sleep (and so do you).  

After all, adults wake up at night all the time!  When you wake up in the middle of the night and fall right back asleep it doesn’t bother you.  It’s waking up and then laying there awake for another hour or two that exhausts you.

If you are looking for a better way to get your baby to sleep well at night,  including great ways to get baby to sleep in their bassinet or crib instead of your arms, my absolute favorite book is The No Cry Sleep Solution for Newborns.  And if you are at all open to the baby ever spending any time in your bed, Sweet Sleep is also amazing and evidence-based.


Popular baby sleep programs, sleep methods or sleep training systems that cause a very young baby to sleep 8-12 hour stretches without feeding can be damaging to your milk supply and your baby may be underfed. Please be very careful and consider other sleep education sources that are made specifically for exclusively breastmilk fed babies under six months old.

Big thanks to my colleagues and IBCLCs Annie Frisbie, Leah Segura, Johanna Sargeant, and Lori Atkins for sending me additional weight charts for this piece, and Chanelle Andrews, CBS for her editing help! 

Please note: This blog post includes Amazon affiliate links. If you purchase items through Amazon after following my links above, I earn 4% of the purchase price.

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One thought on “Why sleep training and breastfeeding don’t mix (and what to do instead)

  1. What about a 4 month baby who continues to breastfeed every 2 hours around the clock? I have been considering sleep training to try and get 4 hour stretches (with 2 feeds) overnight. Our current situation is not sustainable (5 feeds + up to additional 2 wakes) and I am considering a transition to formula due to lack of sleep.

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