Baby sleep

The 4-Month Sleep Regression and How to Get Through It

Are you exhausted from your child's four-month sleep regression? Here's what you need to know.

The 4-Month Sleep Regression and How to Get Through It

Photo: iStock/LisaValder

The early days of parenthood can be joyful but also overwhelming and, frankly, exhausting. Parents of newborn babies have to deal with so many challenges. The list is seemingly endless, from food to changing diapers and what to do with the baby all day.

However, things get easier once you settle into a routine and get to know your baby. But then things suddenly change. One of the biggest challenges new parents face is the first sleep regression, which begins at around four months.

But how do you know your baby is experiencing sleep regression, and how can you be sure? What are some sleep regression signs? And what are you supposed to do about it other than feel exhausted and potentially lose your mind?

Here’s everything you need to know about the 4-month sleep regression and the best advice from experts about handling it so you and your baby can finally sleep through the night again.

Baby sleeping iStock

What is the 4-month sleep regression?

If your baby’s sleep-wake cycle suddenly turns worse and lasts more than a night or two in a row, they might be experiencing a sleep regression. According to Dr. Harvey Karp, founder of Happiest Baby, Pediatrician, and author, the 4-month sleep regression is the first sleep regression that your baby might have.

He tells me, “Babies often go through their first sleep regression at about four months old. For the first 12 weeks, babies usually wake to eat. But at the end of their 4th trimester (around four months), babies transform into little social butterflies who love to chat and play, even in the middle of the night!” While exciting, these things can majorly impact a baby’s sleep.

However, while this can be a change for both baby and parents, Carolynne J. Harvey, Pediatric Sleep Consultant and Founder of Dream Baby Sleep, which offers sleep coaching, courses, and guidance to parents, tells me this isn’t necessarily bad. Sleep regressions, including 4-month, 5-month, 6-month, and 12-month, can be considered developmental milestones.

While frustrating, it’s something we should reframe as a progression. “The four-month regression is actually a progression—it’s when babies move from erratic, newborn sleep cycles to more adult-like sleep patterns, as their bodies begin producing melatonin, the sleep hormone.”


Harvey also notes that methods that previously soothed the baby to sleep, such as motion or feeding, may stop working during this period. Unfortunately, this can also be the cause of the sleep regression. “They may have difficulty linking sleep cycles, leading to short naps and constant night wakings, as they don’t yet know how to put themselves back to sleep,” she explains.

Keep in mind that growth spurts can also cause sleep regressions. So, if you notice your little one’s pajamas are getting tight or their leggings are starting to look a little bit short around the four-month mark—it could be because they are having a growth spurt.

baby sleeping iStock

How long does the 4-month sleep regression last?

While any parent with a child who is currently in a sleep regression will tell you it lasts too long, according to Dr. Karp, there isn’t a definitive answer because every child is different. “While the 4-month sleep regression may feel like it lasts forever, hopefully, it will only go for a few days to a week.”

However, things can go the opposite way entirely, and this sleep regression can start a whole new sleep pattern of frequent waking, which Dr. Karp tells me can last for months.

Like Dr. Karp, Harvey tells me there isn’t a hard and fast rule about how long the sleep regression will last, “But usually it lasts a couple of weeks,” she explains.


Another thing to understand about the 4-month sleep regression is that it should be considered a guideline more than anything else. “It can start between 3 and 5 months,” she explains. So, if your baby’s 4-month sleep regression feels a little early or just a bit too late, don’t worry—it is actually on time.

Is the 4-month sleep regression the hardest?

While it might feel like the hardest you’ll ever go through as a parent, the four-month sleep regression isn’t necessarily the most challenging. “Because the 4-month-sleep regression is often a parent’s first experience with sleep regression, it can certainly feel like the hardest regression,” says Dr. Karp. “But there are so many tools that can help young babies fall back asleep at this age.”

One easy thing Dr. Karp recommends is that parents try using a white noise machine, rocking the baby, or offering a pacifier. “For many, the 18-to-24-month sleep regression can be the trickiest because you’ve got a chatty, mobile, defiant toddler on your hands.”

And this may signal a reminder to start sleep training if you haven't already.

Harvey shares a similar sentiment. “The four-month sleep regression can definitely feel brutal since you’ve already endured the newborn period of sleep and may just feel like you’re getting your sleep back when it seems like everything falls apart again,” she explains. "But then again, not every baby will have a four-month sleep regression that feels difficult for the parents, so it’s just hard to say!”

baby sleeping iStock

How do I deal with 4-month sleep regression?


Knowing this sleep regression is only temporary helps parents deal with the 4-month sleep regression. However, there are various things parents can do to get through this challenging time. One easy thing that most parents can do is to get a white noise machine going when you're putting your baby into their crib.

“Make sure you use a good, rumbly white noise machine that’s just as loud as a soft shower during your baby’s bedtime routine—and throughout the night,” says Dr. Karp.

white noise machine, 4 month sleep regression Merchant

Additional feedings during the day can also help reduce nighttime hunger, so being hungry won’t rouse your baby awake at 3:00 a.m. or another inconvenient time. Lastly, Dr. Karp suggests adding a dream feed around 10:00 p.m. or 11:00 p.m. to fill your baby’s tummy. Babies wake up in the middle of the night if they are hungry.


But no matter what you choose, good sleep habits and a consistent bedtime routine are essential. “Consistency is definitely important—keep your sleep cues like a dark room and white noise machine, and have a consistent bedtime routine,” says Harvey.


What can you do during the day to help your baby sleep better at night?

Dr. Karp recommends going outside, especially if the weather is good. “Get some extra morning sunshine and fresh air to help your baby’s brain correctly balance the natural sleep hormone, melatonin,” he explains. Doing activities to tire your baby out and having a consistent nighttime routine can also help your baby sleep better. However, it’s important to understand that there is probably no magic bullet to fix the problem; it is a consistent routine and combination of things.

Can a noise machine help your child fall asleep faster?

Falling asleep can be a lot easier with the help of a white noise machine, especially if your baby is having a 4-month sleep regression (or a sleep regression at any other time). Dr. Karp specifically recommends using a white noise machine with a rumbling sound to increase this method’s effectiveness.

You can also consider using a white noise app or playing a white noise video on YouTube, which are free and plentiful.

Should I get blackout curtains or shades to help my baby’s 4-month sleep regression?

Light can seriously disturb sleep, especially if your baby is in a sleep regression. Installing blackout curtains or a blackout sleep shade can be incredibly useful in helping your child overcome this challenge. If a new window treatment installation is not within your budget, a blackout rolling shade can be purchased inexpensively from Amazon and self-installed.

What else helps my baby sleep for longer?


Consider setting up the right sleep environment from day one. Aside from a darkened room, consider investing in one of the best baby cribs and best crib mattresses so you know your little one is in a safe and healthy sleep environment. Limit paint and carpets with VOCs, which some studies suggest could interrupt healthy sleep patterns for people of all ages and stages.

Some parents also swear by using sleep routine techniques, where they run through the same set of tasks each evening before putting Baby down. While this differs in every home, it could look like a warm bath, following by lotion and gentle massage, then cozy pajamas and lullabies before being placed down.

The idea is that as each bit of the routine is finished, the baby begins to understand they're nearing closer to the end point—counting sheep and deep, restful sleep.

And overall, know that by the time they're five months of age, your baby will be onto the next thing.


  • Carolynne J. Harvey, Pediatric Sleep Consultant and Founder of Dream Baby Sleep.
  • Dr. Harvey Karp, founder of Happiest Baby, Pediatrician, and author

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