4-Month Sleep Regression

Understanding 4-Month Sleep Regression in Babies

New parents are easy to spot in a crowd—they’re the ones with dark circles under their eyes. That’s because newborns wake up multiple times during the night to feed and haven’t quite learned to distinguish between day and night. After a few weeks, though, most babies start to sleep for longer stretches, giving their parents some much-needed rest.

But just when new parents are starting to feel human again, the four-month sleep regression hits, and they’re back to multiple wake-ups. The four-month sleep regression is the first of several times during the first two years of a child’s life when developmental milestones lead to disruptions and changes in sleep. Not all babies experience every sleep regression, and each child is impacted differently, but the four-month sleep regression is the most common.

Read on to learn more about why the sleep regression occurs and what you can do to help your baby (and yourself) get through it.

What is Sleep Regression?

Sleep regression occurs when a child who was previously sleeping well suddenly begins waking frequently or having trouble going to sleep. While every child is different, sleep regressions typically last anywhere between two and six weeks.

You can usually tell if your child is in the midst of a regression if his habits change significantly. For example, he may go from sleeping for six hour stretches at night to waking every hour or so. Maybe he used to go down easily and now he’s fighting every nap. While every baby has a bad night of sleep now and again, a true sleep regression can be identified by sleep trouble over several days.

Sleep regression occurs because of developmental milestones, so while it can be rough on babies and parents, sleep regression is actually a sign that your child is developing normally. Changes in sleep patterns or milestones like crawling or talking can temporarily wreak havoc on sleep. Be sure to note that sleep disruptions due to travel or illness don’t indicate a sleep regression.

Though sleep regression is normal, it does still come with challenges. Sleep deprivation is hard on babies and parents alike and can lead to impaired cognitive functioning and trouble with mood regulation. Your baby will likely be crankier than usual or need extra comforting. Sleep regression is temporary, so you don’t need to worry about any long-term impacts. Just be sure to keep an eye on your own mental health and ask for help if you need it.

If you’d like to learn more about sleep regression in general, check out our comprehensive guide to sleep regression.

The 4-month Sleep Regression

The four-month sleep regression is the most common because all babies go through changes in sleep patterns around this age. Newborn babies appear to sleep almost all the time, waking only to feed or if they have another need, like a wet diaper. As their brains develop, babies become alert more often, and somewhere between three and five months, their sleep cycle also matures to become much more like an adult’s.

There are four stages of sleep, and we cycle through them during the night. Newborns spend all of their time in stage 3 non-REM (non-Rapid Eye Movement), or deep sleep, and stage 4 REM (Rapid Eye Movement). Because they quickly fall into deep sleep, newborns are easily rocked or nursed to sleep.

Around four months, however, babies add stages 1 and 2 to their sleep cycles and start moving through all four stages. Stages 1 and 2 are characterized by light sleep, so it may become trickier to lay your sleeping baby down without waking her up. Babies around this age also start waking up at the end of a sleep cycle, just like adults do. Unlike adults, though, they may not have the skills to put themselves back to sleep. While all of this is a normal and necessary development, it also means that your baby may have a harder time falling asleep and/or may wake up several times during the night until she gets used to the change.

In addition to sleep pattern changes, several other milestones occur around four months that might interrupt sleep. Babies often go through growth spurts at this age and may need to feed more often. Many begin rolling over, too, and might want to spend more time practicing this new skill and less time sleeping. You may even find that your baby rolls onto his stomach during the night, gets “stuck” and cries out for your help. With rolling comes an end to swaddles, and the transition from swaddles to wearable blankets can lead to trouble sleeping.

Many find the four-month sleep regression to be the most difficult because it’s the first that most parents experience. It also comes at a time when you’re just starting to develop a routine. Try to remember that sleep regression is temporary and usually lasts two to six weeks at most. If your child’s sleep problems last longer than this, or you sense there is something more serious going on, be sure to consult your pediatrician.

How to Help Your Baby through the 4-month Sleep Regression

If you’re in the midst of the four-month sleep regression, or anticipating it, you’re probably desperate for tips to make it as pain-free as possible. While there’s no way to prevent the four-month sleep regression, there are ways to help your baby through it:

  • Remember It’s Normal: Whenever babies go through big changes, especially those that disrupt sleep for everyone, it’s normal to worry. The first step for making it through the four-month sleep regression is to ease your mind and remember that it’s a normal—and healthy—development. If you can, think of it as a progression rather than a regression. This may not help you get more sleep, but it should help take your anxiety down a notch.
  • Encourage Independent Sleep: Part of why the four-month sleep regression hits hard is because babies at this age usually haven’t learned to fall asleep on their own. They’re typically rocked or nursed to sleep, which makes sense for a newborn. Once sleep patterns have matured and babies wake up at the end of a sleep cycle, though, they may not know how to fall back to sleep without being rocked or nursed. As much as possible, practice putting your baby down drowsy but awake. You can start doing this even before the four-month regression hits. Your baby may protest, but she’ll eventually learn to self-soothe herself to sleep, and she can use this skill when she wakes during the night. Each family is different, but many parents take the four-month sleep regression as a signal to start employing some form of sleep training.
  • Provide Comfort: While you want to avoid developing any sleep crutches during this time, you also want to provide all the comfort your baby needs. If your baby is in a growth spurt, he may want to feed more (though probably doesn’t need to do so every hour—you be the judge). Your baby might be crankier than usual due to a lack of sleep. Provide lots of snuggles and attention during the day to soothe your baby. You can even soothe him during the night without necessarily holding him or nursing him all night. Try rocking his bassinet when he fusses or laying a hand on his chest until he falls back to sleep.
  • Be Consistent: The four-month sleep regression may feel like the worst time to stick to a schedule, but doing so can actually help ease you through it. Babies thrive when they know what to expect, so try to have bedtime and nap times occur around the same time every day. Keep with your bedtime routine, including lots of soothing activities like a bath, stories and lullabies.
  • Create a Calm Environment: Creating a calm sleeping environment can help ease your baby into nap and bedtime. A dim room will help signal it’s time for bed, and a white noise machine can soothe your baby while muffling any external sounds. Be sure to allow for plenty of down-time and one-on-one snuggles. Especially as your baby learns to fall asleep on his own, a calm environment can help signal that it’s time to sleep.
  • Employ Help: Remember to keep an eye on your own well-being during a sleep regression. Try taking turns with your partner when it comes to who gets up with the baby during the night. Let household chores slide for a bit, or ask friends and family for help, and catch up on sleep when you can. That might mean skipping after-dinner TV time in favor of an earlier bedtime, but you’ll likely be happy you did.


While the four-month sleep regression can be one of the more difficult milestones for new parents, it’s also a signal that your baby’s sleep is maturing. It’s important to remember that the four-month sleep regression is normal and, like most things in parenthood, it’s temporary. We’ve outlined ways to get through it and minimize the challenges.

At the end of the day, do what you need to do to ensure your family gets the most sleep possible. Sleep deprivation, even if temporary, can negatively impact moods and functioning, and good sleep is important for child development. Keep an eye on your family’s well being and don’t be afraid to ask for help.

Additional Sleepation Resources

For more resources on childhood sleep, check out these other excellent Sleepation guides:

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