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4 Month Old Preemie Development

In general, the medical community believes that preemies need extra time for their developmental milestones, in order to catch up to babies that were born at full term.

4 month old preemie development, would be behind that of a 4 month old full term baby.

It’s all based on the adjusted age.

Adjusted age is basically the age of your baby based on their due date, not their birth date.

There’s argument on if twins follow this same rule, since full term is reached earlier than that of a singleton, but I digress…

Check out this post on the wonder weeks developmental theory and its impact with twins.

@ Team Cartwright

It’s so easy, as parents, to compare your child with others, to look at statistics and expect a certain timeline of events.

4 month old preemie development

It is important to realize that the averages that we read about, are just that- averages. This means that some babies do this skill much earlier, and some much later, but most do it around the average age calculated.

Sitting is a good example. The average age that babies learn to sit unsupported, all by themselves, is 6 months. This is the average for full term babies.

Caroline, our oldest, sat unsupported at 5 months. She was ahead of the curve on this. But, when it came to rolling over… she had no interest. She wasn’t actively rolling until 8 or 9 months if I remember right.

That’s the thing with babies- they are human. They have interests. One baby might be super excited to roll over, while another could care less.

We have to consider the averages, but also give our babies leniency to be human. To have their own interests, temperaments, and skills.

So, with all of that being said, I think it’s valuable as parents to hear real stories, instead of just “statistics”.

William was born at 34 weeks 2 days. He is currently a little over 4 months old. His adjusted age, however, is only 3 months.

Here is our update on his progress with development and milestones…

4 Month Old Preemie Development (William’s Story)

At 34 weeks and 2 days, I was induced due to cholestasis. William was a whopping 6 lbs 3 oz (very big for a preemie)!

He spent exactly 1 week in the NICU.

His feeding and sleeping schedules have been the same, or ahead of, what we experienced with Caroline.

Check out this mom’s post on feeding and sleeping schedules for preemies.

@ Twin Mom and More

What he could handle for his wake time was slightly behind what we’d experienced with Caroline in the first month.

He was quite the sleepy newborn and hard to get full feedings with him, but he quickly caught up.

Learn how to nurse a sleepy newborn here.

@ Chronicles of a Babywise Mom

At 4 months old, he’s doing a 2 hour wake time, and eating every 4 hours. He’s eating 5 times a day, with 3 naps. He only wakes once at night, typically around the 3 am hour.

He puts himself to sleep, and soothes himself well.

See a full breakdown of his 4 month old schedule here.

Posts of Interest

ideal wake times
4 Month Old Preemie Development
NICU preemie challenges and benefits


Here are some of the major milestones that happen in the first 4 months of life, and how William is doing with his progress towards these milestones.

4 month old preemie development born at 34 weeks 2 days

Rolling over

William rolled over for the first time at 5 weeks 6 days from belly to back.

At 4 months old, he’s gone about 90% of the way from back to belly. He can’t quite get his arm out from under his body.

Grabbing Toys

At about 3.5 months old, William successfully grabbed a toy, shook it and inspected it.

4 month old schedule

Thumb Sucking

At 3.5 months old, he also found his thumb and can successfully get it to his mouth, and away from his hand to suck on.

thumb sucking 4 months old

Supported Sitting

If you look at William when he’s doing tummy time, he’s got good strength. He lifts his head up and gets up on his arms pretty well.

As soon as you prop him up, however, he slouches over.

He leans to his right side, and really struggles to sit supported.

supported sitting 4 months old smiling baby


I don’t remember the exact timing of his first smile, but around 12 weeks, he was smiling all of the time. Nice big smiles!

Laughing and Talking

At 4 months, he’s really starting to experiment with his voice. He chuckles, and engages in “conversation”.

This is probably his favorite thing to do. He just lights up when we can give him dedicated time, eye contact, and chat with him.

Now all of that being said, he is a quiet baby and doesn’t talk a lot.

Following with Eyes

Also at 4 months, he’s gotten very good at listening to us, and watching us. If he hears someone, he can turn and find that person with his eyes.

He sees a good distance and can follow them as they move around.

William’s Overall Development Considered by the Pediatrician

Yesterday, William had is 4 month old check up.

They started by weighing him. He was 11 lbs 10 oz.

The nurse left and we waited to see the doctor.

The nurse returned and requested to take his weight again. I knew in that moment he hadn’t gained enough.

My worry flags went up as she explained she was just double checking her measurements.

4 month old preemie development milestones

Weight Gain

When the doctor came in, he explained that William hadn’t stayed on the “curve” for weight gain.

He was NOT at all concerned. Not yet, anyways.

He explained that he looks at a few factors: genetics, birth weight, and the averages.

William was a big preemie (6 lbs 3 oz).

We are small people. He literally looked at our 4 year old, then looked at me, and said “You are both thin, small builds. I don’t know about your husband, but I’m guessing this is William’s natural build as well.”

My husband is as well. That made me feel so much better. I thoroughly appreciated that he considered William’s genetics as a part of the overall picture.

He then explained that since William was so large for a preemie, he thinks he’s most likely just slowing his growth to get back on his natural curve.

We’ll see him back in 1 month for another weight check, just to keep an eye on things. In the meantime, however, he was not concerned and said to just keep doing what we’re doing.

Muscle Tone

William is definitely behind on his muscle tone. His head control is lacking for a typical 4 month old.

This is where is preemie status is evident.

The doctor mentioned that he can tell, based on this factor alone, that William was a preemie.

Again, it is nothing to be concerned about. He’s just not where a typical 4 month old would be.

He’s about a month and a half behind… which is also what his adjusted age would naturally reflect.


When it comes to things like rolling, talking, smiling, cooing, laughing, grabbing, middle of the night wakings, etc. – William is right on track.

Other than his muscle tone, the doctor explained he wouldn’t have noticed he was a preemie, since he’s right on track with all of these developmental milestones.

In other words, he’s doing great!

Other Factors to Consider

I worry. I’ll be honest. It’s hard not to.

Especially in the world we live in, where information is right at our fingertips, and we see updates from our friends on social media daily about their baby’s progress, etc.

It’s hard not to compare. It’s hard not to think back to Caroline’s progress in certain areas, and notice the difference from child to child.

I do, however, think it’s so important to consider the whole picture.

I also think it’s important to know that it’s ok! It’s ok for a premature baby to be slightly behind, or to be hitting milestones based on their adjusted age instead of their actual age.

Those same statistics we look at for each milestone, also show that premature babies catch up!

“A baby born at 36 weeks may not be caught up at 6 months, but may be at within the normal range by 12 months. A baby born at 26 weeks or less may not catch up until they’re 2-and-a-half or 3 years old.”

And for every baby, not just the premature, there are still other factors to consider…

Youngest Child

Being the youngest child, he doesn’t get as much attention as our oldest did. It’s just how life is, unfortunately.

Birth order and the age difference is going to affect how much attention each child gets. Life gets busy.

We are driving Caroline to preschool, picking her up, taking her to activities, etc. That means that often, William’s wake times and/or naps are on the go.

I hate that. Hate it.

But it is what it is and I can’t change it. We have to do those things. That means less interaction, and more time in the car.

It means having to be flexible with naps and feeding times if his schedule doesn’t line up perfectly.

It means that I don’t get as much one on one time. I don’t get to read as many books.

My time, even at home, is split between two children, and getting things done.

4 Month Old Preemie Development

If my 4 year old throws a fit… guess what!? I have to help her calm down. I have to deal with that situation. In the meantime, William is left to wait.

The reverse happens as well, of course. I am feeding William, or getting him down for a nap, or giving him attention, and my 4 year old wants more of me.

Having two children at home simply means that my time is split. There isn’t enough of me to go around.

Here are some great tips on dealing with two children under 2 years of age. I think the same tips apply to everyone, though! We do these even with our situation (4 year old and a 4 month old).

@ Christine Keys

William doesn’t get as much face to face time with me as Caroline did at this age. He gets more independent play than Caroline ever did. He doesn’t get quite as much sitting practice, or tummy time.

I do as much as I can. It never feels like it’s enough. I so wish it was more.

I worry sometimes that he’s behind in his muscle strength because of me. Because I haven’t done enough. But the reality is that it’s not my fault. And it’s ok.

He’s going to get there when he’s ready.

Temperament and Interests

Babies have different temperaments and interests and natural skills.

People have different temperaments and interests and natural skills.

Sometimes I think we focus too much on the averages, and too little on the person that our babies are.

Learn about the 5 different temperament types, at this post.

@ The Journey of Parenthood

There are loud people, and quiet people. There are people that are drawn more to physical skills and are naturally gifted with sports than others.

There are people that are quiet observers taking it all in, and there are people that love to show their skills to the world.

William is quiet. He doesn’t like to talk a lot. He doesn’t fuss a lot. He’s flexible and carefree.

Bottom Line

At the end of the day, all things considered… William is doing great!

I follow the wonder weeks book (outlining developmental milestones), and he seems to be right on track.

Baby Sleep Solutions
The Highly Sensitive Child Book
The Wonder Weeks Book
Childwise Book
Pottywise Book
Preschoolwise Book
Toddlerwise Book
Babywise Book
Baby Sleep Solutions
The Highly Sensitive Child Book
The Wonder Weeks Book
Childwise Book
Pottywise Book
Preschoolwise Book
Toddlerwise Book
Babywise Book

The book explains over and over that baby’s aren’t going to check off every single skill on the list for each leap. Some babies try it all a little bit, and some focus most of their attention on a few skills.

He’s showing his interests, and he’s showing his calm, quiet temperament.

4 month old schedule

We’re working on his muscle tone, and now doing head and neck exercises, even more tummy time, and really working with him a lot.

When I was first told by doctors to expect delays, I ignored it. I knew he wouldn’t be delayed for his whole first year as they described.

I may or may not have been right… we’ll see! But the reality is that it is ok for him to be delayed in doing things if that happens.

So far, other than his muscle strength, he’s keeping up and doing very well.

Wonder Weeks and Leaps

See our children's progression through each of the wonder weeks and leaps.

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