Just when you thought you had bedtime beat: your baby is fussy and wakeful. Not to worry; after helping hundreds of new parents navigate the dreaded 4-month sleep regression, I’ve got 10 tips you need to get things back on track.

Meet our expert Rachel Turner Certified Sleep Sense™ Consultant, Owner, Hello Sleep

What’s happening?

At 4 months, even good sleepers suddenly experience a 2-3 week sleep regression, when they won’t sleep and wake frequently at night.

The good news? It’s not actually a regression at all—it’s more like a progression: a sign your baby’s sleep cycle is maturing. She’ll be on this new cycle for the rest of her life.

The challenge? At this age, your baby’s also learning to roll over, absorbing language, recognizing faces, becoming more active—all milestones that can contribute to sleep regression.

Is it normal?

Very normal—although it can be trying for mom and dad. Newborns only experience two sleep cycles a night. But at 4 months, your baby starts cycling through 4 stages of sleep, like adults.

Suddenly, she’ll spend more time in a lighter, non-REM sleep stage, causing more frequent wake-ups. And it may take her a little time to adjust.

What can I do about it? 

Knowing it won’t last forever can be a comfort—but here’s what you can do in the meantime.

1. Slowly break sleep associations

Learning to sleep independently can be hard for babies—and negative sleep associations can make sleep regression even more challenging. 

2. Use lightly weighted sleepwear

During the 4-month sleep regression, a little extra comfort can go a long way. A lightly weighted swaddle (if baby isn’t rolling over yet) or sleeping bag will help keep her calm and cozy.

3. Feed as much as needed

It’s not uncommon for babies to experience an increase in appetite during a sleep regression. The 4 month sleep regression often coincides with a growth spurt that will make baby extra hungry.

4. Black out the nursery

Newborns aren’t afraid of the dark, but they do respond to light; it tells their brains that it’s time for activity. So at bedtime, the darker the better—especially during a sleep regression.

5. Put baby down drowsy, but awake

Getting baby in the crib before they’re totally asleep helps teach them how to fall asleep independently—it’s also going to help you break those sleep associations.

6. Keep it quiet

Any extra noise is going to distract baby from sleep, especially now that they’re spending more time in lighter sleep stages.

7. Stick to your routine

The 4-month sleep regression might make it difficult to stay on your normal schedule but skimping on your routine will make it that much harder to get to it once the regression is over.

8. Adjust baby’s bedtime

To compensate for shorter naps during the day, try moving bedtime ahead. Not getting enough will make baby overtired, only adding to the fussiness of the four-month sleep regression.

9. Give them time to practice

The 4-month sleep regression usually coincides with babies learning to roll over. Your baby is trying to master this new skill and might think bedtime means practice time.

10. Don’t do it alone

The 4 month sleep regression, while only temporary, can be utterly exhausting. Be sure to take care of yourself: Your own overtiredness can actually rub off on your baby.

4-month sleep regression Survival Guide

Get through the sleep regression with this pre-sleep checklist, helpful mom hacks, and a wakeup-tracker.

New mom sleep hacks

Common questions from tired parents

• What is a sleep regression?
  A sleep regression is a period of time, usually from 2 to 6 weeks, when your baby suddenly wakes frequently during the night and fights/refuses to sleep when previously they had been sleeping well. Sleep regressions occur at 4 months, 8 months, 12 months, and 18 months, with the 4-month sleep regression being the most common.

• Can I prevent the 4-month sleep regression?
  Because the 4-month sleep regression is due to inevitable changes in your baby’s sleep cycle and development, there’s really no way to avoid it altogether. However, you can prepare for it by working on breaking sleep associations ahead of time.

  I find that the other major contributor to this 4 month fiasco is that up until this point parents have either been putting their baby to sleep with a pacifier, by rocking them, by breastfeeding them to sleep, or some similar technique where baby is helped along on the road to falling asleep. These sleep associations can be very sneaky indeed, because although they may be helpful in getting your little one to that initial nodding off stage, the lack of them when baby wake up means that she’s not able to get back to sleep again without some outside help. When this starts happening every half an hour, parents can find themselves in a nightmare.

  To make the sleep regression easier on you and your baby, make a point of breaking these sleep associations before the 4-month mark. Instead of using a sleep aid or creating a sleep association, focus on creating a soothing bedtime routine and getting into a schedule to prepare you for the inevitable sleep regression.

• Does every baby go through the 4-month sleep regression?
  While the 4-month sleep regression is most common, not all babies experience it. You may luck out and have no trouble at the 4-month mark. However, sleep regressions also commonly occur at 8 months, 10 month, 12 months, and 18 months. Your baby might experience all sleep regressions, or none of them!

• What causes the 4-month sleep regression?

  To fully understand what’s happening to your baby during the 4-month regression, you must first learn a little about sleep in general. There are more stages to sleep than simply “awake” and “asleep.” These different stages make up your sleep cycle, which we go through several times a night.

  Stages of Sleep

  Stage 1	The initial stage we're all familiar with where you can feel yourself drifting off, but don't really feel like you've fallen asleep...like when your husband is falling asleep on the couch and you nudge him and he says, "I'M NOT SLEEPING!"
  Stage 2	Considered the first "true sleep" stage. This is where people tend to realize, once woken up, that they actually were sleeping.
  Stage 3	The deep and regenerative stage. Also known as "slow wave" sleep, this is where the body starts repairing and rejuvenating the immune system, muscle tissues, energy stores, and sparks growth and development.
  Stage 4	REM (rapid eye movement) sleep. This is where the brain starts to kick in and consolidates information and memories from the day before. It's also the stage where we do most of our dreaming.

  Adults cycle through the four stages and either wake up or come close to waking up. Think about how you’ll barely wake in the middle of the night and shift positions or open your eyes for a split second before falling right back to sleep. Newborns, however, only experience two of the four stages of sleep: stage 3 and stage 4 (or REM) and spend about half of their time asleep in each stage.

  As a newborn, you were most likely able to rock or nurse your baby to sleep and put her down without her waking.  This is because she jumps right into that deep sleep stage. Around 4 months old, your baby will start cycling through all 4 stages of sleep, instead of just two.

  When this change takes place, our little one moves from 50% REM sleep to 25% in order to make room for those first two stages. Although REM sleep is light, it's deeper than these 2 new stages that they're getting used to. With more time spent in lighter sleep, there's more of a chance that baby's going to wake up. This adjustment period is the primary cause of the 4-month sleep regression.

  Other developmental milestones, like learning to roll over, can also contribute to the 4-month sleep regression.

  If you'd like to learn more about sleep cycles, check out our article Your Baby's Sleep Cycle.

• How long does the 4-month-old sleep regression last?

  The 4-month sleep regression usually lasts anywhere from 2 to 6 weeks. It takes time for your baby to adjust to this new sleep cycle, which is what’s causing them to wake up more frequently. Usually this transition is coupled with additional milestones. Around the same age, your baby might be in the beginning stages of learning to roll over. They’re also absorbing more language, recognizing faces, and just becoming more active and alert in general.

  While exciting, these milestones can get distracting come bedtime. Make sure you’re engaging baby during the day and giving them time to develop any new skills, so they’ll be less likely to try practicing in their crib at night.

• Can the 4-month sleep regression happen before or after 4 months old?
  The 4-month sleep regression could begin as early as 3-months-old or as late as 5-months-old. It’s more about when your baby’s sleep cycle starts changing—for most, it’s right around the 4-month mark, but it could be a little earlier or a little later. Every baby is different!

• How much should a 4-month-old sleep?

  At 4-months-old, your baby needs about 12 to 15 hours of sleep for every 24-hour period.

  Typically, 4 to 6-month-old babies will get 6-8 hours of their sleep during the night, with 1 to 2 awakenings in between to feed. From 4 to 6 months old, your baby will start staying awake longer in between sleeps and you’ll notice more distinct sleeping patterns emerge. Now you’ll be able to get them on a more consistent nap schedule and can start to expect a bit more sleep at night.

• Does swaddling help with the 4-month-old sleep regression?

  Yes, swaddling can help babies calm and sleep better during the 4-month sleep regression. However, some babies might also be learning to roll over around the same time, which makes swaddling unsafe. Before trying to swaddle to combat the 4-month sleep regression, check for the 6 signs it might be time to stop swaddling.

  If your baby is in the clear, consider using the Zen One™ swaddle. It’s gently weighted on the chest and sides to provide extra soothing comfort, plus the breathable mesh sleeves are removable. So once baby does start showing signs of rolling over, they can still wear the Zen One with their arms free.

  If swaddling is no longer safe, the Zen Sack™ can give similar comfort during the sleep regression thanks to the gently weighted Cuddle Pad™ on the chest.

• How is the 4-month sleep regression different than other sleep regressions?
  The sleep regression is the most common of all the sleep regressions and is most directly linked to a permanent change in your baby’s sleep cycle. Although a regression is defined as 'reversion to an earlier mental or behavioral level,' this one’s actually a ‘progression.’. Once you're through the 4-month sleep regression, your baby will have officially moved into the sleep cycle that they'll essentially follow for the rest of their life!

• Can Zen Sleepwear™ help with the 4-month sleep regression?

  Gently weighted Zen Sleepwear can offer extra comfort during an extra fussy time, like the 4-month sleep regression. Many parents have said that using Zen Sleepwear helped their baby get through the 4-month sleep regression more easily. Parents who introduce Zen Sleepwear during a sleep regression also see improvements in sleep.

  If your baby is used to and likes to be swaddled, the Zen Swaddle® or Zen One™ are great options, especially if baby is still experiencing Moro reflex. For babies who have already started learning how to roll over, the Zen Sack™ still offers the comforting gentle pressure but gives baby a little more freedom.

• What else should I expect at the 4-month mark?
  The 4-month-old mark officially ends the newborn stage – bittersweet, right? Your baby is growing, becoming more curious, and settling into routines. For the first 3 months of your baby’s life, they spent more time asleep than awake, but now you’re noticing she’s staying awake a bit longer between naps, learning to grasp and maybe even in the beginning stages of learning to roll over. Learn more about baby sleep from 4 to 6 months.

Related links

8 solutions to get your baby to sleep through the night