Understanding the Dreaded Four Month Sleep Regression

baby's sleep pattern ruins your sleep

By Cara Dumaplin, RN

"He was sleeping great, but suddenly he started waking up every hour. It's harder now than when he was a newborn." Oh this story is so common when I'm speaking to sleep deprived parents. "It all started at about four months. I'm at a loss of what to do."

The dreaded "four month sleep regression" has struck. Let me see if I can simplify it for you and truly help you understand what is happening with your little one's sleep. 

What is the Four Month Sleep Regression

So, it's not really a "regression" per se. At about 3-4 months of age, our babies move from the newborn phases of sleep into more adult-like sleep stages. 

The Science Behind it: 

These sleep stages string together into "sleep cycles". These cycles last 60 to 90 to 120 minutes during the night. The end of each cycle has a characteristic mini "wake-up". Yes, you and I "wake up" five to eight times per night. This is our body's protective measure to check our surroundings and validate that we are, indeed, safe. Our bodies expect our sleeping environments to be unchanged from when we initially fell asleep. 

Now, you and I have gotten so good at putting ourselves back to sleep after these mini wake-ups, we don't even know we were briefly awake. 

Here's an example of my sleep. It demonstrates just what I'm talking about on the Fitbit: 

 fitbit restless night

Fitbit calls it "restless", but it's actually a mini "wake session". Now, I thought I slept great on this particular night. I didn't feel restless or know that I was moving about or ever awake for a total of 24 minutes. I, like you, put myself back to sleep without ever knowing I am awake. 

Great! How Does This Apply To My Baby?

Well, at 3-4.5 months of age, he will go through these sleep cycles and at the end of 60, 90, or 120 minutes each night his body will slightly awaken him. He will check in with his environment making sure that everything is okay and his surroundings are unchanged. 

For those who attended my newborn class, "Will I Ever Sleep Again," you have been working on setting your baby down to fall asleep. Now, this is when it really pays off. If your baby put himself to sleep in his own crib/bassinet, he hits this 4 month old new sleep cycle, awakens slightly, and looks around.  (Remember, our bodies expect our sleep environment to remain unchanged.) He knows his crib and knows how to put himself back to sleep. He drifts back to dreamland. Boom! Four month sleep regression conquered. It's all good! No issue! 

However, what if your baby is rocked or fed to sleep? She, too, will enter this stage of new sleep cycles. So, she fell asleep in mom's arms and then is set down in the crib when she's fast asleep. After about 60, 90, or 120 minutes, she will awaken and check in with her environment. Guess what she says during the check in: "Hey, this isn't right! My surroundings are different. I was in Mom's arms. Where am I now? In this horrible, awful crib!  Waaaaaa! Mama, come get me."  (Can you blame her? What if you fell asleep in your bed and awoke a few hours later in your neighbor's bed? Wouldn't you freak out and cry?) Our bodies expect our surroundings to be unchanged during these wake-ups.

So, what do Mamas do when our babies cry in the night? Well, we assume they must be hungry so we feed them and they fall back to sleep. One to two hours later, they do it again. We convince ourselves that he must be having a growth spurt. We offer another feeding. Then 1-2 hours later... awake again! A few nights of this, and now, a large majority of baby's calories are being consumed at night. Their little bodies become accustomed to this frequent waking. They will need to be rocked or fed back to sleep.  This is the beginning of sleepless nights and labeled "the 4 month sleep regression."

Add In Some New Developmental Changes: 

At about this same time, our babies become aware of the big world around them. During the day, they suddenly notice big brother playing with toys, the dog running around the room, the light from our cell phone flashing, and all sorts of other exciting happenings in the environment that before was just background noise. All of these things are way more interesting than eating. So our 4 month olds naturally get shortened, smaller feedings as they become more distracted by this exciting, big world. 

Couple that with all the extra feedings baby received last night and there's really no reason to eat well today. Right?

So, guess what happens tonight? He awakens every 1-2 hours in accordance to these new sleep cycles, but he's genuinely hungry because he didn't eat much during the day. This creates a cycle of night wakings with multiple feedings due to poor (or not-so-great) daytime feedings. 
Make sense as to why nights turn into nightmares? 

So, What Can Be Done? 

  1. Attend/Watch "Will I Ever Sleep Again" while you're expecting or in the first 10-12 weeks of your baby's life. I'm telling you…this REALLY helps. Watch what parents are saying about this class at TakingCaraBabies.com (under “Newborn Class”).
  1. Truly work on setting your baby down while awake. Learning to fall asleep on his own is never easier than in the first three months of life. No, I'm not saying that you can't ever hold your baby while she's sleeping. I promise! I love holding sleeping babies too! Watch/attend the class. I'll explain how to create this balance. 
  1. Recognize the change in sleep cycles at three to 4.5 months of age. Prepare your mind that it will happen. 
  1. Put your baby down drowsy, but awake at bedtime.
  1. When your baby awakens at the top of a natural sleep cycle, give him a few minutes to put himself back to sleep. A bit of fussing or grunting may be heard. It's ok! You do the same thing in the night. Don't intervene right away. Give him a few minutes to put himself to sleep. (This may be a good time to transition your baby to her own room if you haven't already. Seeing mom or dad while transitioning between sleep cycles may cause the "mini" wake-up to be a "full blown" wake-up. Again, the timing of this transition is a personal decision for each family.)
  2. Know your baby's current night feeding patterns. Let's say you implemented the tips in my class and your 3 month old is eating at 7:00pm, 5:00am, and again at 7:30am. You would easily recognize when your baby awoke at 10pm, 11:30pm, 1am, 4am, and 6am that he PROBABLY isn't hungry. Implement other techniques taught in the class to get your baby back to sleep other than feedings. For example, allow him to put himself back to sleep. If he doesn't, offer the pacifier, rock his swaddled body side to side, and shhhhh. By all means, do not unswaddle for nighttime sleeping unless your baby is consistently rolling over. Then, check into the Zipadee Zip. The Zipadee-Zip is the perfect swaddle transition for babies that have started to roll, but still need a bit of snugness to feel secure.
  3. Maintain adequate feedings during the day. Continue offering feedings every 2.5-3.5 hours during the day. If your baby is distracted during a feeding take him into a darkened, boring room. Turn your cell phone off too. 

 baby wakes up

8. If everything falls apart and you recognize that the "4 month sleep regression" (which is really just a change in the sleep cycles) has reeked havoc on your nights...seek help. If by 5 months of age your baby isn't sleeping through the night, consider getting a sleep plan created. A sleep plan helps your baby overcome the issues that make your nights unbearable and can slowly wean the night feedings and get your baby sleeping 10-12 hours EACH and EVERY night. 

Your nights don't have to be exhausting any more. 

Also read:Tackling the Four Month Sleep Regression

enjoy the four month sleep regression

Cara Dumaplin, Founder of Taking Cara Babies, is not a blogger. She is, however, a mom to four kids who keep her laughing daily. Although she swore she would never date a doctor, it is with joy that she admits marrying her husband (a pediatrician) was the beginning of a crazy-amazing life together. (Albeit, she has had to learn to forgive him for constantly feeding their kids Pop-Tarts for breakfast.) A registered nurse with 18 years experience, Cara's eyes light up when she discusses her passion of educating, encouraging, and empowering new parents. Conquering sleep deprivation is her goal. Follow Taking Cara Babies on Facebook or Instagram for helpful baby sleep tips, successful infant sleep stories, and a glimpse into this chaotic, yet blessed life. For more blogs by Cara, check out here.

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