You’ve finally reached the point where your baby is sleeping for solid stretches during the night, and is maybe even falling into a predictable nap routine. Now all of a sudden, she’s waking up and fussing like a newborn again. Is this a bad dream?

Nope. Chances are you’re in the throes of the 4-month sleep regression. It’s a perfectly normal part of your baby’s development, but it can leave you straight-up exhausted.

Fortunately, that bleary-eyed feeling isn’t back for good. Here’s a look at why baby sleep can sometimes turn rocky around this age, plus some smart strategies for getting through it.   

What is the 4-month sleep regression?

Sleep regressions are blips on a baby’s sleep radar where she wakes up more often throughout the night or has a harder time napping.

Sleep regressions are completely normal and often occur at predictable times during your little one’s first year — including the 4-month sleep regression, which can actually hit any time between 3 and 4 months.

It’s also common for sleep regressions to strike at around 6 months, 8 to 10 months and 12 months.

These hiccups can happen when a baby passes through a major developmental stage, like learning how to flip over, crawl or pull up. But they don’t last forever: Once she’s acclimated to her new skill, her sleep patterns should go back to normal. 

How long does the 4-month sleep regression last in babies?

Sleep regressions affect babies differently, and some infants may take a little longer to get back to their usual sleep habits than others.

But they do end. Provided you stay consistent with your baby’s bedtime routine and take steps to avoid forming any potentially bad habits (more on that below), the 4-month sleep regression should end on its own in about two weeks or less. 

Causes of the 4-month-old sleep regression

Sleep regressions, including the 4-month sleep regression, are usually the result of your baby passing through a big developmental milestone. Your little one is understandably eager to practice her new skill, which can leave her restless and prone to waking up more often than normal.

The 4-month sleep regression may be happening because:

  • Your baby is trying to master rolling or flipping over. In her eagerness to hit this milestone, your baby is waking up more overnight and having a hard time settling down for naptime and bedtime.
  • Your baby is becoming more aware of her surroundings. It can be tough to sleep soundly when you can’t stop noticing all the fascinating new things around you to see and play with!

Signs your baby is going through the 4-month-sleep regression

Sleep regressions are often a case of "you know it when you see it." One day, your baby is snoozing normally. Then, all of a sudden, she’s not. 

By 3 or 4 months, most babies are able to sleep for five-hour stretches at night without waking up. Some might even regularly go for six to eight hours. Either way, your little one has probably developed a fairly typical pattern in terms of when and how often she wakes throughout the night.

A night or two of unusual wake-ups probably doesn’t count as a regression. After all, everyone sleeps poorly once in a while, and babies are no different. 

But here are some signs that the 4-month regression is what you're dealing with:

  • Your baby is regularly waking up more often than her normal pattern, especially if there doesn’t seem to be an obvious reason behind it, like travel or illness. 
  • During the daytime, you notice that your baby is working on practicing a new skill like rolling over.
  • Your baby has suddenly become way more interested in her surroundings. Maybe she gets distracted more easily while eating, for instance, or she has a harder time dozing off in places other than her crib. 

Tips for managing the 4-month sleep regression in your baby

Aside from having extra coffee on hand, it’s all about being consistent. While you can’t control whether your little one wakes up during the night, you can set the stage for helping her sleep as well as possible — and hopefully, keep her from getting overtired.

Follow these tips for dealing with the 4-month sleep regression:

  • Stick with your regular bedtime routine. That’ll encourage your baby to unwind before bed — and reinforce the message that nighttime is for sleeping. If you aren’t already doing so, get into the habit of putting your baby down while she’s drowsy but awake. If she’s used to falling asleep on her own, she may have an easier time dozing back off when she wakes up in the middle of the night. So refrain from letting your baby fall asleep in your arms.
  • Help your baby stay rested. Babies this age generally need 12 to 17 hours of total sleep, including nighttime and naps (for babies 0 to 3 months old, it's recommended that they get a total of 14 to 17 hours of total sleep, and for those 4 to 11 months, 12 to 15 hours of total sleep is suggested). That generally amounts to between 10 and 12 hours at night, though it varies. If the regression is causing her to get less and she seems tired during the day, help her make up for the lost shut-eye with a little more naptime. She’ll settle down easier at night if she’s not overtired. 
  • Don’t make a big deal of the wee-hour wakings. The best thing to do is to treat the disruptions like you would have in the past. If you normally give your baby a few minutes to fuss it out before going in to offer a reassuring pat, do the same thing now. Sticking with your usual routine will help you avoid forming bad habits, where your baby needs even more help to fall back asleep. More intense sleep-training methods like cry it out aren’t typically recommended for babies younger than 4 to 6 months, but speak with your pediatrician to make sure your baby seems ready.
  • Try not to rely on feedings. Many 3- and 4-month-olds still eat once or twice overnight. But if your baby is waking up more frequently or at other times when she doesn’t typically eat, try to soothe her without the breast or bottle. Offering more opportunities to eat could set the stage for your little one to continue expecting extra nighttime snacks, even after the sleep regression has passed. 
  • Keep your cool. Sleep regressions are exhausting while you’re going through them. But they do end. So try not to get too worried or stressed about them. And try to stay calm when you're with your baby.

When to call the doctor

A stretch of rocky nights by itself isn’t usually cause for concern. But you should touch base with the pediatrician about night wakings if:

  • Your baby is eating less than normal during the day.
  • Your baby is having fewer than four wet diapers and three bowel movements per day.
  • Your baby doesn’t seem to be gaining weight. 

The 4-month sleep regression isn’t fun, but it’s a perfectly normal part of babyhood. The key is helping your baby stick with her usual sleep habits as much as possible (and maybe sneaking in a nap yourself). Within a few weeks, you should both be back to more solid snooze time.