4 Month Sleep Regression

4 Month Sleep Regression- Expert Advice

Everything YOU Need to Know About the 4 Month Sleep Regression

Most parent’s experience the 4 month sleep regression when their baby’s are anywhere between 3 months and 5 months old. I see it time and time again in Facebook Mom Groups, “My baby is 3 months old. They used to sleep through the night and now they are waking up every 45 minutes. What is wrong with my baby? Are they going through a sleep regression?” Or, “My 5 month old has barely slept for a month, are they going through a sleep regression? What do I do?” I promise you, you are not alone! You are not the only parent looking for answers because their baby just started struggling with sleep. The 4 month sleep regression is normal. There are reasons behind the sleep regression and there are solutions to the 4 month sleep regression.

I am a certified pediatric sleep consultant who is going to share with you the science behind the 4 month sleep regression. Discussed is WHY the 4 month sleep regression happens to most baby’s and WHAT you can do to help your baby through the sleep regression.

Why do babies go through a 4 month sleep regression?

There are a few reason why baby’s go through a sleep regression between 3 and 5 months of life. The three main reasons your baby may be going through a 4 month sleep regression are a change in bedtime attire, growth spurt, and sleep cycle pattern change.

1. What is your baby wearing to bed?

Around 3 months old, baby’s start to roll which means they can no longer be swaddled for bedtime. The reason we swaddle our babies is because a swaddle helps the baby feel like they are in a tight environment similar to when they were in the womb. We also swaddle them because baby’s have a moro reflex causing their body’s to automatically jerk around which wakes them up. 

Swaddle Safety

Swaddles are safe and effective when used correctly for baby’s who are not rolling over yet. They should be used to help hold your baby’s arms against them. According to the International Hip Dysplasia Institute, a a baby’s legs should not be swaddled because it can increase the risk of hip dysplasia and dislocation. Baby’s are used to being in the womb with their legs bent for many months. It could lead to serious problems if a baby’s hips are constricted.

Transitioning Out of Swaddle

Instead of transitioning right to a sleep sack, it may be best to transition your baby into Magic Merlin suit. If you baby has begun rolling over but are not consistent with rolling over from back to stomach, I would recommend transitioning your baby to the Merlin suit. The Magic Merlin suit is great for helping your baby’s reflexes. It is also difficult for your baby to roll in if they have not mastered rolling. The Magic Merlin’s additional help for your baby’s reflexes can help decrease wakings.

If you use the Magic Merlin suit, you want to make sure your baby is getting enough tummy time. They need to have the opportunity to strengthen muscles and learn to roll over.

Once your baby has mastered rolling over, you can transition them from magic merlin suit to a sleep sack.

2. Is your baby waking in the middle of the night hungry?

Around 4 months is when one of the biggest growth spurts happen for your baby. You may notice that when your baby isn’t sleeping well at night, that they are also wanting to eat more.

Make sure your baby is getting the recommended amount of ounces of breast milk or formula during the day. You will want to look up how many ounces your baby needs in a 24 hour period based off their age, weight, and if they drink breastmilk or formula. Most baby’s around 4 months will be drinking 4-5.5oz of breastmilk every 2.5-3 hours during the day, equaling to be about 30oz during the day. If you are exclusively breastfeeding then make sure to feed your baby off both breasts each feeding. Formula fed baby’s usually drink 5-7 oz every 4 to 5 hours, equaling about 32oz during the day. Please talk to your pediatrician and make sure your baby is getting the right amount of formula or breastmilk everyday.

Perfect Baby Daytime Routine

I would suggest getting into the eat, play, sleep routine. Fifteen minutes after your baby wakes up feed them a full bottle or have them nurse off of both breasts. After, play with them for about 1.5 hours. Then, lay them back down for a nap. A 4 month old baby’s wake window should be around 1.5 to 2 hours. A feeding should take about 30 minutes. Play time should be about 1- 1.5 hours. Naps should be about 45 minutes to 1.5 hours long.

Sample Schedule for 3 Month Old Baby:

7am Wake

7:15am Feed

8:30am-10am Nap

10:15am Feed

11:30am-1:00pm Nap

1:15pm Feed

2:30pm-4pm Nap

4:15pm Feed

5:30pm-6:30pm Nap

6:45pm Feed

7:45pm Bedtime Routine Including Feeding

8pm Bedtime

Sample Schedule for 4 Month Old Baby:

7am Wake

7:15am Feed

8:30-10am Nap

10:15 Feed

11:45am-12:45pm Nap

1pm Feed

2:30pm-3:30pm Nap

3:45pm Feed

5:15pm-5:45pm Cat Nap

6pm Feed

7:15 Bedtime Routine Including Feeding

7:30pm Bedtime

Sample Schedule for 5 Month Old Baby:

7am Wake

7:15am Feed

9am-10:30am Nap

10:45am Feed

12:30pm-2pm Nap

2:15pm Feed

4pm-5pm Nap

5:15pm Feed

6:45pm Bedtime Routine Including Feeding

7pm Bedtime

3. What does the sleep science say about the 4 month sleep regression?

Baby’s sleep cycles change as they get older. Newborn to 3 months, a baby’s sleep cycle consists of two phases, active sleep and quiet sleep. Active sleep is when a baby is in a phase that is like REM (dreaming phase), which is why you see your baby jerking around as they sleep. The quiet phase is when your baby does not move at all. They are almost impossible to wake, you can flop their little arms around and it does not phase them at all.

Around 4 months is when a baby’s sleep cycle goes from this 2 phase sleep cycle to a 5 phase sleep cycle, just like adults. A baby’s sleep cycle is around 50 minutes, and you may be noticing your baby wakes every 50 minutes. That’s because they are having difficulty connecting their sleep cycles. After completing a sleep cycle they enter a very light phase that wakes them up, then they have difficulty going back to sleep on their own.

The good thing is, around the time the 4 month sleep regression starts, your baby has begun to develop their circadian rhythm. The circadian rhythm is our 24 hour internal clock that is controlled by zeitgeber’s (which means, time givers or time cues). Zeitgeber’s are light, eating, bowel movement & temperature patterns. Our circadian rhythm prepares and tells us when to sleep, when to wake up, when to use the bathroom, and so much more. The circadian rhythm is responsible for our melatonin production at night and our cortisol production in the morning. 

How to Train Your Baby’s Circadian Rhythm

You can train and use the circadian rhythm to help your baby sleep well. For instance, it’s best to get your baby out in the sun in the morning. At night it’s best to avoid blue and white lights. Even using your phone near your baby in a dark room emits blue light into their retina and decreases their melatonin production. The only light that does not mess with melatonin production or sleep wakings is red light.

Other things you can do to train your baby’s circadian rhythm is feed you baby every single day at the same time. This is when the eat, play, sleep routine mentioned above comes in handy!

It only takes 3 days of consistently looking at the clock for meals, bedtime and wake time for the circadian rhythm to adapt. Then their circadian rhythm will begin causing these things to happen automatically at the same time everyday. If you wake your baby everyday at 7am, they will begin to wake on their own everyday at 7am. 8am breakfast? You baby will begin to get hungry everyday at 8am. You may even notice your baby having a bowel movement everyday at the same time.

How to Help Your Baby Connect Sleep Cycles

Working with your child’s circadian rhythm will help with this key sleep component I am about to share with you.

The solution to helping your baby connect their sleep cycles is to teach them the skill of falling asleep independently. Falling asleep independently means that they are putting themselves to sleep on their own without any parental assistance.

The way a baby falls asleep, is the way they will expect to go back to sleep when they wake in the middle of the night. If you nurse you baby to sleep, they will expect for you to nurse them to sleep in the middle of the night. Do you rock your baby to sleep? Yep, you guessed it! If they wake in the middle of the night, their expectation is that you will rock them back to sleep.

How can I teach my baby to fall asleep independently during the 4 month sleep regression?

A baby learns the skill of falling asleep independently when they have the space to learn. Baby’s, just like older kids and adults, may get upset while trying to learn a new skill. My older son who is a gentle hearted kind child became so infuriated while learning the skill of riding his bike. He would peddle two times, fall off, throw his bike, kick it, yell, then get back on and try again. He eventually learned how to ride a bike and rides all around town now.

As long as your baby’s needs are met and you know they are safe, it is okay to give them that space to learn how to fall asleep independently. Research shows that allowing your child to have space to figure out the skill of independent sleep may result in some crying and that is safe and okay. Allowing your child the space to try will not harm them. That time is actually harder for Mom than it is baby. After a woman has a baby her brain changes to be more alert when her baby cries.

If you are not comfortable giving your baby space to learn to fall asleep independently, then there are other more gentle sleep training methods you can choose. There are sleep training methods that are hands on. A couple sleep training methods keep you present for your baby. There is even one where you give your baby space but check in on them to give them the reassurance that you are still there. Checking in also gives you peace of mind.

4 Month Sleep Regression Additional Support from a Certified Pediatric Sleep Consultant

If your baby is going through a 4 month sleep regression, hiring a certified pediatric sleep consultant could change your life.

How Hiring a Sleep Consultant Changed My Life

I know hiring a sleep consultant can change your life because my husband and I hired a sleep consultant for our son when he turned one.

Before hiring a sleep consultant I would have to nurse and bounce on a exercise ball for 45 minutes to get him to sleep. Once I got him to sleep, I would have to crawl into bed with him at night. Then, he would wake up every hour to comfort nurse. He took over our king size bed and my husband had to sleep in a different room. The only place he would nap was his car seat. I was exhausted and becoming physically sick.

After hiring the sleep consultant, our son now sleeps independently. Sleeping independently looks like him sleeping in his own room and in his own crib for 11-12 hours at night. During the day he take one long nap in his crib (he is 16 months now). I do not have to assist him to go to sleep when it’s time for him to rest. My husband and I get to sleep in our king size bed together. We also get to have a full night of sleep! The experience of hiring a sleep consultant changed our lives! I decided to become a certified pediatric sleep consultant so I can help other families get the sleep that they desperately need!

Benefits of Hiring a Sleep Consultant

A pediatric sleep consultant looks at the whole picture: environment, food intake, bedtime routine, daytime routine, naps, sleep attire, wake windows, hours of sleep a child is getting, and your parenting style. Then, makes you the perfect sleep plan to help your child start falling asleep independently. 

The best thing about hiring a pediatric sleep consultant is support that you will receive. They will give you the best education, advice, and encouragement while you teach your baby to fall asleep independently. 

When clients work with me I provide:

Free 15 Minute Call to Discuss Sleep Issues

-Detailed Personalized Sleep Plan

-30 Minute Consultation Phone Call Discussing Sleep Plan

-2 Weeks of Support and Encouragement via Text

-Wrap-Up Call where I Answer Any Question’s You May Have

-Ending E-Mail Where I Share Frequently Asked Tips and Sleep Tips that You Personally Will Need as Your Baby Develops

If you desire to have more rest, wellness and freedom, please schedule a FREE 15 minute call with me today! I would love to educate, support, and encourage you while you confidently get your baby sleeping better!

You can also schedule a FREE 15 Minute call by going to my website and clicking the button at the top of the page!

Sleep Blog Posts Coming Soon:

Benefits of Hiring a Sleep Consultant

How Sleep is Vital for Baby’s Development

Perfect Newborn Sleep Schedule

Teething & Sleep Training


Information About Proper Swaddling: https://hipdysplasia.org/infant-child/hip-healthy-swaddling/

Research on Baby’s Sleep Cycles: ncbi.nlm.nih.gov/books/NBK526132/

Study on “Cry it Out” being Safe and Effective: https://acamh.onlinelibrary.wiley.com/doi/10.1111/jcpp.13223

Circadian Rhythm Information: How Babies Sleep: The Gentle, Science-Based Method to Help You Baby Sleep through the Night by Sofia Axelrod, PhD