When you buy through links on our site, we may earn an affiliate commission. This keeps it 100% reader supported and free of ads or sponsorships. Thanks for your support!

Get our Survival Guides

4 Month Sleep Regression

And JUSSSST when you thought you had the whole sleep-thing figured out — yeah, that’s right, you’ve mastered the mysteries of the baby-sleep-universe — BOOM! You hit the dreaded “4 month sleep regression.” Baby’s up again at night; perhaps even several times a night.

Fuuuuuuhhh…! This isn’t supposed to be happening… or is it?

You’re probably very confused if you don’t know what’s going on behind the curtain. Let’s have a look.

The Skinny

Technically speaking, a healthy, full-term 4-month-old baby **should be able to go about 8+ hours at night without needing to eat. By 5 months, they’ll typically go for 10-11 hours without a snack. Hot damn!

** “Should” does not mean “will.”

Yes, just because they can go for a stretch without eating doesn’t mean the sleep gods will be smiling upon you this month. Nay. In fact, the 4th month is a time of massive neurological change, as well as changes to your baby’s sleep patterns. Specifically…

Maturing Sleep Patterns

Over the 4th and 5th months, non-REM (i.e., deep sleep) increases as the pineal gland starts to secrete more and more melatonin, meaning your babe will sleep more soundly than she did as a newborn. On the downside, it also means that she’ll be more ALERT at the end of each sleep cycle, more like an adult. The catch is that adults know how to get themselves back to sleep in the middle of the night (unless you’re an insomniac like me); infants usually don’t.

Hence, the “partial arousals” they experienced between sleep cycles as newborns (and probably fell right back to sleep without anyone noticing) may well turn into full-on wake-up-crying arousals.

Most parents are totally thrown for a loop by these new night-wakings and begin to search for answers to this strange, unsettling pattern: is she hungry? Is she teething? Maybe she’s lonely? Ah, yes, I know, she’s lactose intolerant; that’s the ticket! (Etc., etc.)

You might be fooled into thinking that she’s waking out of hunger, but it’s probably not the case (especially if she’s waking at a time when she wasn’t before!). I mean, heck, as parents, we’ve been TRAINED to feed them every 3 hours since the time they were born (or else!). Sometimes, it’s harder for us to stop the knee-jerk reaction to feed them because we’re sooooo conditioned to do so, right? Having said that…

D i $ t R @ C t I 0 N

Just to be extra confusing, 4 months is also a time when babies seem to be way more distractible while nursing/feeding during the day (look, a squirrel!) and may in fact (is that our dog? I love the dog!) be eating (come here, doggie!) less than they normally do (I love dogs. Hey look, a window!) during the day (wait, is that mom’s hair I just grabbed? Hair is awesome).

This is a totally different matter altogether. To cover all your bases, pay special attention to baby’s daytime milk consumption [nursing moms may have a harder time gauging this. Sorry ’bout that]. If daytime milk consumption is waning, she may, in fact, be hungry at night. If not? I’m guessing it’s classic 4 month sleep regression. Just something to keep in mind.

19-Week Growth Spurt

Wait, what?

In 2 weeks (at about 4.5 months), your baby will experience another growth spurt where he may be more hungry, in general. You may go through a period when baby is eating ALL. THAA. TIME. Totally normal.

During this time, some nursing moms have trouble keeping up with milk production [I did]. I actually had to supplement with formula and pump a lot to get my supply up, which eventually happened.See also nursing supplements.

When baby wakes at night during this growth spurt, she may wake because she’s in between sleep cycles (classic sleep regression), orrrr because she’s hungry. Who knows for sure? Mwaaaaaa! Isn’t this confusing?!?!

My advice is use your best judgment and observe feeding behavior: if she’s latching on like she hasn’t eaten in days? I’m guessing she’s actually hungry. If she’s latching on for comfort and immediately falling back asleep? Chances are she wasn’t hungry in the first place. Oops. Don’t worry, you’ll figure it out over time. You always do.

Fostering Good Sleep Habits

Okay, back to waking in the middle of the night for no apparent reason —

Babies who have learned how to self-soothe and get back to sleep without a crutch will fare much better than those who rely on mom or dad intervening after each waking (did you miss that article? Click here). Now is a great time to work on self-soothing skills, which will create a solid foundation for sleep-sanity going forward.

Breaking Bad Habits

At this age, try putting your baby down drowsy but awake. It’s hard at first, but doing this will allow your babe to learn how to “put herself to sleep.” It’s true!

If possible, try to avoid having him fall asleep nursing/feeding, rocking in the swing, bouncing in your arms, or riding around in the car as a matter of habit. It’s one thing to drive a newborn around in the car or stroller to calm him, but at this age, you’re just perpetuating a sleep crutch. Now, it’s time for him to sleep in his crib (or wherever he normally sleeps). The earlier you do this, the better. If you wait until baby can roll over, stand up, etc.? It’s muuuuuch harder. Do it now while they are still fairly immobile and can’t fight back. Haha, just kidding (sort of).

I know MANY moms who — even at 8 months of age — still do “that thing” to get their baby to nap every time. For one mom, it was walking outside with baby in the carrier; for another mom, it was putting her 9-month-old in her infant swing every time. I know another 11-month-old baby who has NEVER napped in his crib and will ONLY nap “accidentally” in a stroller or carrier.

I get it: they don’t want to fight nap time battles, but they’re inadvertently fostering a dependence on their crutch-of-choice to get baby to sleep. When babies-who-have-never-fallen-asleep-by-themselves start waking in the middle of the night between sleep cycles, they’re going to have a MUCH harder time getting themselves back to sleep. Like passing out on a friend’s couch after a hard night of drinking, baby will also wake up wondering where her shoes are and how she got there in the first place (minus the cotton mouth, of course).

Don’t be afraid of some tears in order to break bad habits.**

**Sometimes, you just need to hear it from someone else. So there you go. I said it. 😉

Remember: It takes about 3 days to break a habit. Prepare yourself for 3 days of suckage, stay the course, and then you’re home freeeee!

What Not to Do

This is also around the time when many a desperate mom (especially those who’ve gone back to work) resort to putting baby cereal in his bottle (at the advice of well-meaning friends, mothers, etc.) in hopes of making him sleep longer. Most docs now advise against this, as research shows baby cereal in fact does not help babies sleep longer. Doctors agree that babies should wait until 5-6 months before starting solid foods (i.e., “solid food,” meaning anything that’s not milk/formula). Yes, I know; your mother gave you rice cereal at 6 weeks and you turned out okay. These days, it’s sort of a no-no.

I believe if you keep working on good sleep habits, such as putting baby down drowsy but awake and breaking bad habits (persistent use of sleep crutches, etc.), 95% of you shouldn’t have to resort to harsh methods of sleep training down the line. It’s thaaa worst! Let’s see if we can do this naturally and progressively, aye?

4 Month Sleep Regression — Bottom Line:

4 months is a wacky time, y’all. There’s A LOT going on this month that may make it the sh*t!est month of sleep yet because at least with a newborn, you’re expecting to be up all night, right??

Do what you need to do to get through these next few weeks and the 4 month sleep regression should resolve on its own. Be aware though, if you introduce a new nighttime feeding, for example, you may be forming a new, unnecessary habit. Try telling that to a sleep-deprived mom at 3 am and she will smack you in the face. I GET IT, trrrrust me!! Sometimes, I would do ANYTHING to get Baby Alice back to sleep (good habits be damned!). We all do it. Just do the best you can and things should normalize again in 4-6 weeks.

In the words of the Waterboy, “You can do eeeeet!”

P.S. There’s another sleep regression coming around 8-9 months, but by that time, you’ll be a pro!

Exit mobile version