How to get through the 4-month baby sleep regression

Developmental changes, changes in sleep cycles, and a disruption to their routine or feeding schedule can cause your baby to start sleeping worse than they have in the past.;

This phase, called a sleep regression , is a normal part of a baby's development – though that doesn't make it any easier to deal with. Here's how to help your baby get back to sleeping soundly.

Why is the 4-month sleep regression so hard?

Those first few months of your newborn sleeping through the day and waking up at all hours of the night are finally over, and they seem like they're getting the hang of sleeping more regular hours.

Then, suddenly, your baby resists going to bed, wakes up throughout the night, and won't go down for naps – this is the 4-month sleep regression.

At 4 months old , your baby is ready to take the first of many massive developmental leaps. However, changes in their awareness of the world around them and shifts in their sleep pattern can disrupt their established sleep schedule, triggering a regression that keeps them (and you) up at all hours.

Most babies have at least made steps toward sleeping for longer stretches by now. So when your little one suddenly starts sleeping less, it's easy to feel discouraged or like you're doing something wrong. But don't worry – sleep regressions are normal and temporary, and you can take steps to get your baby back to sleeping soundly.

(For more in-depth information about sleep regressions, as well as how to combat them, check out Baby Sleep 101 from BabyCenter Courses.)

What causes the 4-month baby sleep regression

If your little one's sleep changes have you scratching your head in confusion, you're not alone. Several factors contribute to sleep regressions, rather than one specific reason.

Here's a look at some of the most common causes of the 4-month sleep regression:

• Sleep cycle changes. Newborns only have two sleep stages: REM (rapid-eye movement) and non-REM. But around 3 months, their sleep cycle starts to change and look more like an adult's, with four sleep stages (three of these are types of non-REM sleep, and the fourth is REM). This is typically why babies start sleeping for longer stretches, but cycling through these different stages can also cause them to wake up and struggle to fall back asleep as they get used to the new pattern.
• Developmental leaps. Babies generally become more aware of the world around them at this age. This means a baby who previously slept through anything might become more sensitive to light, noise, and changes in their routine. Your baby's sense of awareness also means they can tell when you're not there, which can cause some distress when they wake up. They could also be distracted by newfound skills like rolling over and other developmental accomplishments.
• Illness and discomfort. If your baby has been sick, feeling crummy might contribute to changes to their sleep routine. And while most babies' first teeth come between 6 and 10 months, your baby may start teething early – and that discomfort can disrupt their sleep.
• Changes in routine. Taking a trip , missing a few naps , or staying up later than usual can temporarily disrupt your baby's sleep routine. Any recent changes to your established routine could contribute to a sleep regression.

It's tempting to attribute sleep regressions to physical growth spurts , but research doesn't indicate there's a direct correlation.

"Babies frequently experience short periods of rapid growth referred to as 'growth spurts,' but they don't necessarily go hand in hand with the 4-month sleep regression," says Liz Donner , M.D., a pediatric hospitalist and member of the BabyCenter Advisory Board . "I view the 4-month sleep regression as a side effect of normal brain development."

Four-month sleep regression signs

At 4 months old, babies need about 15 hours of sleep in a 24-hour period. While there's some variation from child to child, you can generally expect this to play out as nine to 10 hours of sleep overnight, along with four to five hours of daytime sleep spread over three naps.

A sign your baby is in a sleep regression is they're not getting the recommended amount of sleep for their age. More specifically, if you've noticed a shift in your baby's sleep patterns resulting in more night waking, difficulty falling asleep for naps and bedtime, waking up fussy, or waking shortly after putting them down, these could be signs your little one is in the throes of a sleep regression.

Outside of recommended benchmarks for the hours of sleep they should get, how can you tell if your baby isn't getting enough sleep? Look for these signs of an overtired baby:

• They resist going to sleep.
• They're often fussy throughout the day and are more difficult to calm down.
• They might fall asleep while eating or refuse to nurse all together.

Other clues like redness around the eyes, yawning, looking away from stimulating things, and lack of interest in people or their environment can be a sign your baby isn't getting enough sleep.

When do sleep regressions happen?

Newborns typically spend around 16 hours sleeping, but their sleep schedule is all over the place in the first three months. Because their circadian rhythm hasn't yet developed, they'll sleep in short bursts.

Once your baby starts getting longer chunks of sleep, you may consider any backsliding a regression – but these setbacks are completely normal.

Regressions can happen any time, but especially at 6 months , 8 months , 12 months , and 18 months . You may have even noticed changes in your baby's sleep schedule at 2 months, 3 months, or 5 months. The timing of sleep regressions is different for every baby.

How long do sleep regressions last?

Since each baby is different, it's difficult to say how long you can expect the 4-month sleep regression to last. However, the most important thing to remember is that it's temporary and will pass with time.

Generally, sleep regressions can last for a few days or up to a few weeks. However, a sleep regression that doesn't resolve and is accompanied by poor eating, poor weight gain , inadequate dirty diapers (babies typically wet their diapers four or five times a day), or failure to meet developmental milestones is cause for concern.

These combined symptoms suggest that underlying medical problems might be contributing to your baby's poor sleep.

While you don't usually need to talk to your baby's pediatrician about a sleep regression, if it lasts longer than four weeks or if your baby has other symptoms you're worried about, check in with their healthcare provider. They can help you figure out if another issue is keeping your baby from sleeping well.

"Navigating infant sleep regressions can be challenging and complex," says Dr. Donner. "No two babies are the exact same, and therefore no single solution is going to work for everyone. When you've tried to address the regression on your own but are still in need of additional guidance, reaching out to a pediatric sleep consultant may be a reasonable next step. Be aware of expensive 'sleep experts' that promise 100% success, as no program can reliably guarantee success when it comes to your baby's sleep schedule."

How to cope with the 4-month sleep regression

When your baby doesn't sleep, life is a challenge! It might feel like you'll never get good sleep again. The good news is that sleep regressions aren't permanent, and your baby will eventually sleep well again.

In addition to practicing patience, here are a few tips for coping with the 4-month sleep regression:

• Establish a routine. If you haven't already, now's the time to adopt a daily routine for predictable nap times and bedtimes . Staying consistent, even when things aren't going well, is one of the most beneficial things you can do for your baby's sleep during a regression.
• Try sleep training. Most experts recommend sleep training when your baby is between 4 and 6 months old, so this is the perfect time to try. There are a few methods to teach your baby how to fall asleep on their own: cry it out , fading , gentle , and the Ferber method .
• Wean off nighttime feedings. Between 4 and 6 months old, most babies get enough calories during the day and can go through the night without eating. If you think your baby is ready, talk to your baby's pediatrician and try to wean them off their night feedings over about two weeks.

Navigating infant sleep regressions can be challenging and complex. No two babies are the exact same, and therefore no single solution is going to work for everyone. - Dr. Liz Donner, pediatric hospitalist

• Track feedings. While your baby might be developmentally ready to sleep through the night without eating, first make sure they're eating enough during the day to make it work. If you think your baby might be waking up because they're hungry, keep track of when and how much they eat, and make adjustments to ensure they're getting enough calories during the day. Find out how much breast milk and formula 4-month-olds need.
• Create a calming environment. At 4 months, your baby is taking more notice of the world around them – which can make sleep a boring prospect. Help your baby get back to sleeping soundly by addressing outside noise, putting a sound machine in their room, and putting up blackout curtains . Make bedtime soothing by keeping things quiet and calm and avoiding screens and stimulating toys before sleep.
• Separate night and day. Because newborns so often sleep around the clock, it may require a habit switch to teach them the difference between night and day. During the day, keep things bright, noisy, and playful. As bedtime approaches, draw the blinds and quiet the house as much as possible.
• Ask for help. Sleep regressions can be just as exhausting for you as they are for your baby. Remember to ask for help from your partner or another loved one. Make sure you're getting several consecutive hours of sleep, eating enough, and getting some time to yourself to reset your own body and brain.

What's a good 4-month sleep schedule?

Your 4-month-old baby's sleep schedule will depend on a number of factors – whether you're breastfeeding or formula feeding being one of the biggest – and may include two to three naps throughout the day. Naps aren't one-size-fits-all at this stage, so they may last anywhere between 30 minutes and 2 hours.

Here's a good sample sleep schedule, though this will vary by family:

• 6 a.m.: Wake up.
• 9 a.m. to 10:30 a.m.: Naptime.
• 12 p.m. to 2 p.m.: Naptime.
• 4 p.m. to 5 p.m.: Naptime.
• 8 p.m.: Bedtime.

Bear in mind that the overnight sleep schedule typically includes waking up to eat roughly every 3 to 4 hours; most babies don't sleep through the night until they're 6 months old.

Can a 4-month-old sleep through the night?

While it's not unheard of for a 4-month-old to sleep through the night, it's not a common – or consistent – occurrence. Babies start to consolidate their sleep around 5 to 6 months old, so you may notice their naps are getting shorter while their nighttime sleep is getting longer during those months.

By 6 months, most babies are sleeping through the night. One study showed that 62.4% of 6-month-old babies were sleeping 6 or more hours consecutively; that number rose to 72.1% once babies are 12 months old.

That still leaves a sizable portion of babies who are not sleeping through the night, so if your little one is in that percentage, it's normal (if not ideal).

Key Takeaways

• The 4-month sleep regression is common and can be just one of the many sleep regressions babies experience during their first year.
• This regression can be caused by leaps in brain development, changes in sleep environment or routine, or illness and discomfort.
• Parents can combat the 4-month-sleep regression by establishing a consistent routine, beginning sleep training, weaning off nighttime feedings, and creating a soothing environment for sleep, among other solutions.