Tips for the 4 Month Sleep Regression Period

Just when you thought your baby’s sleep schedule was finally predictable, the 4-month sleep regression can strike—causing restless nights, skipped naps, and exhausted parents.. Sleep regression in babies is a temporary change in a baby’s otherwise sound sleep schedule which causes them to wake up frequently in the middle of the night, experience poor naps, and behave extremely fussy– and a 4 month old’s sleep regression phase can be one of the worst. In this guide by Baby Brezza, we’ll go over the baby sleep regression process, what it looks like, and how you and your little one can cope with it in the best, easiest way possible.

When it comes to new babies, sleep regression is not one of the fun factors. Learning how to deal with 4 month sleep regression– if it arises, which is likely– can be a stressful, arduous process for parents and babies alike. These hiccups are common and can happen when a baby passes through a major developmental stage, such as learning how to flip over, crawl or pull up. Sleep regressions can be exhausting and frustrating for parents, but it’s a sign that your baby has hit a new and exciting growth milestone and that their sleep cycle is maturing. Baby sleep regressions come and go, and by being able to understand when your little one is going through one of these difficult stages, you’ll be much more set up to help them get through it.

Signs of Sleep Regression

• Frequent nighttime waking
• Difficulty falling asleep
• Increased fussiness and inconsolable for no reason
• Change in appetite
• Shorter nap times
• Disturbed sleep
• Increased impatience

What Ages Do Babies Have Sleep Regression?

Babies may experience their first sleep regression when they are 4-months old. Often mistaken for the duration of the sleep regression, the term “4-month sleep regression” actually refers to the age when the baby's sleep cycle is temporarily disrupted. The four-month sleep regression is most common, but not all babies experience it. You may luck out and have no trouble at the 4-month age mark. However, out of all of the baby sleep regression ages, the four month mark is a very common time for parents to deal with. 

At the four-month mark, babies start a 4-staged sleep cycle and learn how to help themselves get back to sleep when they wake up through a process called “self-soothing”. In some cases, sleep regression can also occur later at 8 months, 10 months, 12 months, or even 18 months depending on how your baby develops.

4 Month Sleep Regression Duration: How Long Does Sleep Regression Last? 

Sleep regressions may last for different durations depending on your baby’s age and environment, however they typically last for two to six weeks. In many cases, babies learn how to self-soothe and fall back asleep on their own. As adults, we are used to rolling over or changing positions when we wake up uncomfortable, but babies have not learned that skill yet. It is important to keep in mind that these regressions are temporary and your baby will move on to sleeping even more comfortably after the regression is over. When they learn to flip, rollover, or crawl, their pattern will likely return to normal. If they have regressions at an older age, it may be due to other factors such as stress, anxiety, or nightmares.

Do All Babies Go Through Sleep Regression?

No– not every baby experiences sleep regression; moreover, not every baby goes through sleep regressions within the same timeframes. The baby 4-month sleep regression period is, however, a very common milestone: in fact, it is the most common regression time among babies. Ensuring an environment that encourages more rest is crucial to getting through this often difficult time, so using soothing methods, blackout curtains, and plenty of time are essential to the process.

Tips to Help Your Baby (and You) Through the 4-Month Sleep Regression

Sleep regressions are frustrating, exhausting, and often unavoidable—but they’re also a normal part of your baby’s development. If you’re in the thick of the 4-month sleep regression, here are practical, evidence-based tips that can help restore calm to your household and support your baby’s sleep journey.

1. Create and Stick to a Bedtime Routine

A consistent bedtime routine is one of the most effective ways to signal to your baby that it’s time to sleep. Repetition builds security, so keep the routine predictable; think bath, pajamas, feeding, a quiet lullaby or book, and lights out. Try to keep the timing and order the same every night.

2. Watch for Sleep Cues

Before babies become overtired, they show subtle signs that they’re ready for sleep: rubbing eyes, yawning, zoning out, or turning their head away. Catching these cues early and putting your baby down before they’re overtired can make a big difference in how easily they fall asleep and how long they stay asleep.

3. Use a Consistent Sleep Schedule

Try to anchor wake-up time and bedtime around the same hour each day. Even if naps vary in length, having predictable bookends to your baby’s day helps regulate their circadian rhythm. If your baby wakes up at different times each day, aim for a “wake window” range instead—within 30 minutes of your target time.

4. Respect Wake Windows

At 4 months, most babies can only stay awake for about 1.5 to 2.5 hours at a time. Putting your baby down within that window can help prevent them from becoming overtired and overstimulated—two things that make it harder for babies to fall and stay asleep.

5. Prioritize Daytime Naps

Sleep begets sleep. Skipping naps or letting your baby get overtired during the day won’t help them sleep better at night. In fact, it often makes things worse. Aim for 3-4 naps spaced across the day, and try to begin winding down before your baby becomes fussy.

6. Darken the Sleep Environment

Light suppresses melatonin, a hormone that regulates sleep. Use blackout curtains during naps and at night to signal to your baby’s body that it’s time for rest. Keeping the sleep environment dark also helps differentiate between day and night.

7. Use Sound to Promote Sleep

Consistent, low-level white noise can help drown out household sounds and soothe your baby to sleep. Choose a constant sound (like a fan or ocean waves) over one that loops or has sudden breaks, which might startle your baby awake.

8. Practice Putting Baby Down Drowsy but Awake

This classic advice is especially important during sleep regressions. While it’s tempting to rock or feed your baby to sleep during a rough patch, doing so every time can create a sleep association that’s hard to break later. If your baby fusses, try short intervals of comfort without picking them up right away to give them a chance to self-settle.

9. Respond with Reassurance, Not Reinforcement

If your baby wakes during the night and doesn’t need a feeding, try to soothe them calmly without turning on bright lights or picking them up immediately. Gentle pats, shushing, or a reassuring voice may be all they need. The goal is to provide support without fully stimulating them.

10. Be Flexible, But Stay Consistent

Regression phases are temporary, so give yourself and your baby grace. If something’s not working, it’s okay to adjust—but try to avoid introducing too many new habits at once. Pick one or two sleep strategies and stick with them for at least a few days to see if they help.

11. Protect Your Own Sleep

If possible, take shifts with your partner or ask a trusted friend or family member to help during the day so you can nap. Regression phases can be hard on everyone, making rest for the caregiver just as important as rest for the baby.

12. Remember This Is a Phase

Above all, know that the 4-month sleep regression doesn’t last forever. Many babies return to better sleep within a few weeks, especially when supported with calm, consistent care. You’re not doing anything wrong—this is part of your baby’s growth, and it will pass.

13. Utilize Tools

If your baby still wakes for a night feeding—a common occurrence at 4 months—keep the experience as calm and low-stimulation as possible to help them (and you) fall back asleep more easily. Avoid turning on bright lights, engaging in stimulating activity, or spending too long preparing a bottle. Tools like the Formula Pro Advanced can be incredibly helpful during this phase. It prepares a warm, perfectly mixed bottle in seconds at the push of a button—no measuring, scooping, or waiting while your baby cries. This lets you respond to your baby’s hunger quickly and consistently, and reduces the chance that a simple feed turns into a fully awake hour-long ordeal.

Sleep regression may be exhausting, but it is a sign that your baby is working towards self-soothing sleep habits that will be better for them (and you!) in the long run.

The Science Behind the 4-Month Sleep Regression

Understanding why the 4-month old sleep regression happens can help parents feel more confident in addressing it.

• Brain Development: Around 4 months, a baby’s sleep cycles mature to resemble adult sleep cycles, with distinct phases of light and deep sleep. This shift can cause frequent awakenings as babies adjust to the changes.
• Increased Awareness: Babies begin to notice their surroundings more acutely, which can make it harder for them to settle back to sleep after waking.
• Growth Spurts and Milestones: Physical growth and milestones like rolling over or grasping objects can also disrupt sleep patterns during this period.

Highlighting the science behind the regression reassures parents that it’s a natural and necessary part of their baby’s development.

4 Month Sleep Regression FAQs

How much sleep should my baby be getting during the 4-month sleep regression?

Babies around 4 months old typically need 12–16 hours of sleep in a 24-hour period, including naps and nighttime sleep. While the regression may temporarily shorten sleep, focusing on consistent routines can help your baby return to longer stretches.

Can I sleep train during the 4-month sleep regression?

Yes, sleep training can start during this time, as long as your baby is healthy and ready. Gentle methods like the "shush-pat" technique or the Ferber method can help establish independent sleep habits.

Does breastfeeding affect the 4-month sleep regression?

Breastfed babies may wake more frequently during the regression due to comfort-seeking or growth spurts. Ensuring your baby gets full feedings during the day may help reduce nighttime wakings.

How do I handle naps during the 4-month sleep regression?

Short naps are common during this phase. Aim for 3–4 shorter naps spread throughout the day to ensure your baby gets adequate daytime rest. Use darkened rooms and white noise to encourage longer naps when possible.