The 4 Month Sleep Regression

The 4-month sleep regression can be awfully painful. Newborns can be pretty good sleepers on their own in the beginning. Then, they get a little older and the 4 month sleep regression strikes.

I always chuckle when I meet a new mom with a 3 week old. “He’s a perfect sleeper!” Wait till he’s 4 months old, mama… just wait.

Even if your baby wasn’t a good sleeper during the newborn stage, the regression can be tough. Right when you thought your baby’s sleep couldn’t get any worse- it did!

Here’s your guide to the 4-month sleep regression: what it is, why it happens and how to get through it.

Signs of the 4 Month Sleep Regression

  • Frequent night wakings
  • Shorter or skipped naps
  • Inconsolable fussiness
  • Weakened appetite during the day

Why does it happen?

Even though it’s called a regression, your baby is not moving backward. Her brain is taking a huge leap forward in development: she’s graduating from newborn sleep to adult sleep.


Newborn Sleep

Newborns only have two types of sleep: active sleep and quiet sleep. Active sleep is when she grunts, kicks, squirms or even cries out in her sleep. Quiet sleep is that deep, still, sleep that is so unique to new babies.

Newborns spend most of their time in deep sleep. Very deep sleep. This is why a newborn can sleep right through a wedding and be so hard to wake for feedings in the first few weeks.

During both active and quiet sleep, newborns are not aware of their surroundings. This is why it can be very effective to rock your newborn to sleep in your arms and then lay her down in her bassinet. She won’t realize you’ve put her down and will slumber in peace until her next feeding.


Adult Sleep

Adult sleep is different. When we sleep, we travel through FIVE stages of sleep within each 90-minute sleep cycle. The stages vary from light sleep, medium, deep, deeper, and REM sleep (when we dream.) Right after the dream stage, we experience a partial awakening. If our pillow is in the right position and we’re comfortable, we fall right back asleep. This happens without even realizing that we woke up. But if something changed, like your pillow fell down or you need a drink, you wake up completely. You make yourself comfortable again, and start the falling asleep process from scratch. This repeats every 90 minutes for adults and every 45 minutes for babies.

The 4 month sleep regression is when your baby’s sleep changes from newborn sleep to adult sleep. Instead of active and quiet sleep, your baby now experiences multiple levels of sleep each time she sleeps. She wakes up every 45 minutes or so to make sure that her surroundings are safe, just like adults do. And now that she’s older, she’s becoming much more aware of her surroundings.

This is why old tricks won’t work anymore. Rocking your baby to sleep in your arms and putting her down in the bassinet won’t work because she won’t fall into a deep sleep in your arms. She will only fall into the first stage of sleep which is very light. As soon as you put her down, she’ll wake up, and now that she’s aware of her surroundings, she won’t be happy that she’s not your arms anymore! You’ll then have to help her fall back asleep all over again.

For a baby to fall into a deeper state of sleep at this age, you’ll need to rock her for at least 30 minutes so that she won’t wake up when you lay her down. And even then, she’ll wake up 15 minutes later at the end of her sleep cycle…remember, the whole cycle only lasts 45 minutes before she wakes up! And the process begins again.

 Smaller Feeds, Greater Hunger

Another factor that contributes to this regression is smaller feedings during the day. Four-month-olds babies get distracted during feedings – the world got a lot more interesting recently! This leads to distracted feedings, causing your baby to often eat a half meal or just a snack at each feed.

This leads to hungry nighttime wakings that are reinforced by night feedings. And so the chicken-and-egg cycle starts: smaller feedings during the day, which leads to more feedings at night, which leads to fewer feedings during the day.

How long does it last?

Even though it’s called the 4 month sleep regression, it can start as early as 3 months or kick in as late as 5 months. The duration and intensity vary from baby to baby – for some babies, it can last just a week or two and resolve itself and for others, it can be extremely difficult and never go away on its own without sleep training.

 How to move through it

  • If you can, wait a few weeks to see if the regression will resolve itself on its own. Make sure your baby is on the right schedule for her age. If things persist after a couple of weeks,
  •  Identify and eliminate your baby’s sleep dependencies and teach your baby how to fall and stay asleep on her own.
  • Make sure to maintain adequate feedings during the day to reverse the night feeding cycle. Wean off of night feedings if necessary.
  • Don’t rush to start solids. This won’t necessarily help.
  • Don’t unswaddle your baby unless he is rolling over.

Bonus Tip🌟

Sleep is deepest before midnight, and after midnight babies will wake up and need your help to fall back asleep every 1 or 2 sleep cycles, which can have her waking up every hour between 1-4am! Between 4-6 am, sleep is at it’s the lightest state of the whole night, so it’s pretty common for your baby to be waking frequently during this time through the regression. Sleep gets (mercifully) deeper again in the last hour before wakeup, when most babies fall back asleep again for another hour of deep sleep.

So keep this in mind: If your baby wakes up early and then falls right back asleep 30 minutes later for a nap, she wasn’t ready to wake up for the day. That was a night waking which tricked you into thinking it was a morning wakeup!


By | 2019-09-17T11:15:09-04:00 September 17th, 2019|Categories: Sleep Troubles|0 Comments

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