3-Month-Old Baby: Milestones & Development

Wait a minute. A 3-month-old baby?! How on earth did that happen?
It’s now been roughly a year since you discovered your world was about to change - and oh, boy, has it changed!

The 3-month mark signals the end of what experts like to call the fourth trimester.

Those first 12 weeks on the planet involve a heckuva lot of growth and development, and it all culminates in the fact that your baby’s now no longer considered a “newborn”.

That’s right. We’re officially in infant territory, mama.

So let’s dive into all there is to know about your 3-month-old baby:

In this article 📝

What should a 3-month-old be doing?

3-month-old infants tend to stay awake for longer periods during the day and, fingers crossed, sleep for longer through the night.

You’ll also start to notice more smiles, more personality, and more head control as your 3-month-old baby continues to blossom.

Meanwhile, they’re Hulking out of their sleepsuits and you’re wondering if anything fits…

And that’s just the tip of the iceberg where milestones are concerned.

What are the milestones for a 3-month-old?

There are lots of exciting 3-month-old milestones!

When you’re with your 3-month-old baby all day, every day, it can sometimes be tricky to spot the small changes as they grow and develop.

But month 3 brings with it a few hard-to-miss moments, so keep your camera within reach:

1. Baby’s on a roll. It’s around now that tummy time starts to pay dividends. Those mini-planks progress into full-on rolls, and eventually, you’ll see your 3-month-old rolling over. Stick with tummy time to strengthen those muscles. And don’t worry about them not rolling back onto their front straight away; this can be harder to master and will take a little longer.
   
2. “Ouch, that’s mama’s hair!” Your baby’s eyesight is improving all the time, to the point that now they’re able to track movement from greater distances. They’re also developing a smidgen of hand-eye coordination. Just enough to grab for something colorful, or take a fistful of your luscious locks.
   
3. Sitting, standing (with support). With a helping hand or two, baby should be able to sit up on your lap and hold their head reasonably steady. And as they continue to adjust to life outside the womb, they may also be able to bear weight on their legs, if you hold them upright in a standing position, that is.
   
4. A world of sights, smells, sounds, and textures. You may take this for granted but look around you. There’s a lot to see, smell, hear, and feel — and baby’s really starting to appreciate that. They don’t yet have depth perception, but they can recognize objects, turn towards loud noises, respond to your unique scent, and actively enjoy different textures. The fun and games are (quite literally) about to begin.

How much should a 3-month-old eat?

All of this development requires fuel, so how much should your 3-month-old baby eat?

At this point, your baby’s stomach has naturally grown in size, so they should be able to go longer between meals.

If you’re wondering how many ounces does a 3-month-old eat?, the answer is around 5 ounces.

Trust yourself that you know the difference between when your baby’s hungry or just fussy, and if you have any concerns, don’t be afraid to ask for help on Peanut.

3-month-old feeding schedule

So how often should a 3-month-old eat?
Whether you’re still breastfeeding (around half of mamas are at this point), mixing boob and bottle, or you’re using formula, you’ll probably find that baby will eat between six and eight times a day.

This is roughly every three to four hours each day.

Of course, this will vary from one little one to another, and you need to do what’s right for you and your baby.

So if you’re after a feeding schedule for 3-month-old, the best thing to do is aim for every three to four hours, or whenever baby starts getting hungry.

What can a 3-month-old eat?

When it comes to 3-month-old feeding, your options are pretty limited.

Until around 4 months, breast milk or formula has all the nutrients your growing 3-month-old baby needs.

But if baby’s on the latter end of 3 months, you can always test the waters with a few baby-friendly foods:

• Pureed peas
• Pureed squash
• Pureed bananas
• Pureed peaches
• Pureed apples

However, for a 3-month-old baby, these should be in addition to breastfeeding or formula ‒ little bites of food to introduce new textures and tastes to baby.

How much should a 3-month-old weigh?
The average weight for 3-month-old baby is 5.4kg (12lbs) for girls and 6kg (13.2lbs) for boys — but remember, this is just an average.

For a more accurate take, check your 3-month-old baby’s weight in relation to their length on a height-weight chart:

• If both height and weight are on a similar curve, then all should be okay. They might be a bit bigger or smaller than the average, but rest assured, they’re on the right track.
  
• However, if weight is outpacing height (or vice-versa), speak to your pediatrician or healthcare provider. This could be a sign that your baby is gaining weight too quickly (or not fast enough).

How to play with 3-month-old baby

By now, your 3-month-old baby has discovered that there’s more to life than eating, sleeping, and pooping — although those activities will still take up a healthy chunk of their day.

So, now you need to incorporate some entertainment into the mix.

Don’t worry, you won’t need to learn how to juggle, and a unicycle is, almost certainly, overkill.
Instead, fall back on the oldies but goodies: songs, toys, and stories.

• Books with different textures or sounds built-in will always go down a treat at this stage. You could also try using different voices, tones, and noises as you read.
  
• Classic nursery rhymes and songs will elicit smiles and giggles (from you both). Try and incorporate baby’s name so they get used to hearing it.
  
• Bright, colorful, squeaky, or rattly toys will be popular too, as baby starts to grasp, examine, and explore.

Read also: 6 Toys for a 3-Month-Old & Nine 3 Month Old Baby Activities

How much should a 3-month-old sleep?

If you’re lucky, this is the point where baby starts to sleep through (most of) the night.

For an infant, this is typically seven to eleven hours of uninterrupted snoozing.

However, you should bear in mind that if your baby falls asleep at 7pm or 8pm, this stretch of slumber could take them up to around 2am to 7am.

Still, that’s better than being woken several times throughout the night!

As for a 3-month-old bedtime, that’s up to you! You can aim for a nighttime sleep starting at about 9:30pm for a later wake-up.

But how long should 3-month-old nap? Well, baby will also partake in a few daytime naps to top up their beauty sleep (usually between two and four, totaling four hours).

To avoid your baby becoming overtired and therefore less likely to sleep through the night, keep your eyes peeled for signs that they’re ready for bed.

So plan their naps with big enough intervals (around 1-3 hours) before their nighttime sleep, so they’re not overtired.

If they’re fussier than usual, wanting to nurse or take a bottle when they’re clearly not hungry, or rubbing their eyes, it’s probably time for their jammies.

In terms of safe sleeping practices for a 3-month-old, your baby should still be sleeping in the same room as you to reduce the risk of sudden infant death syndrome (SIDS), and if they’ve shown signs of rolling over, you should stop swaddling them.

The bottom line when it comes to 3-month-old baby sleep is to try and stick to a consistent routine.

Keep bedtime and nap times the same, day in, day out, and you’ll both reap the benefits!

My 3-month-old won’t nap

There are a few potential culprits as to why your 3-month-old baby is refusing to get some shut-eye:

• Overtired: Baby hasn’t had enough sleep today (or the day before), so they could be grumpy, not knowing that sleep will make them feel better. The advice here is to try to create a peaceful sleeping environment (ideally in their own home) and stick it out!
  
• Overstimulated: Baby’s had a busy day, meeting new people, trying new things, playing new games, so their mind’s in overdrive! Just like with an overtired 3-month-old baby, making their scene as relaxing as possible is the best thing to do.
  
• No routine: Building a sleep routine can be beneficial to both you and baby ‒ you can plan your day, and they can get the sleep they need to develop and grow! Work out a 3-month-old baby schedule for naps and sleeping that you can stick to.

Read also: What’s the Best 3-Month-Old Sleep Schedule?

How far can a 3-month-old see?

Baby’s eyes are still developing, so there’s a lot they can’t quite see just yet.

Your 3-month-old baby can see people and objects around 15 inches away clearly, although they can’t tell how close they are.

Baby may also be following moving objects around the room, like people, toys, and pets.

What size shoe does a 3-month-old wear?

Your 3-month-old baby may be between shoe sizes right now.

They’re on the cusp of two different age ranges for shoe sizes, so they could either be a US 1 or a US 2 (that’s around 3.5 to 3.75 inches).

How often should I bathe my 3-month-old baby?

Your 3-month-old baby should only need a bath about once or twice a week.

The bathtime is partly for cleanliness, but also for engaging playtime.

However, it’s not recommended to bathe your 3-month-old too regularly (like daily), because it can take the moisture from their skin.

If you’re keen to use baths as part of your nighttime routine to help baby sleep more soundly, you can do it, just don’t use soap for every bath.

Why is my 3-month-old drooling so much?

Your 3-month-old baby might be drooling a lot, but that’s nothing to worry about, mama.

It can mean that baby’s digestive system is developing, getting ready to process something other than breast milk or formula.

However, 3-month-old baby drool can cause a rash. If you’re worried about your baby’s rash, it’s best to check with your pediatrician.

3-month-old drooling could also be a sign of teething ‒ but the only way to tell if this is the case is seeing new teeth popping up in baby’s mouth.

Read also: Baby Teething at Three Months? What to Know

Does this get easier?

You’ve almost certainly uttered that question throughout the first 12 weeks of being a mama, and at 3 months in, you now have an answer: Sort of!

It’s not that being a mama is any easier; it’s that you’re better at it now.

You can spot signs of hunger and tiredness, you know your way around a dirty diaper, and you can feed with your eyes shut.

When you combine those finely honed skills with your 3-month-old baby settling into something resembling a routine, everything becomes that little bit more predictable.

Of course, life with a baby will throw you quite a few curveballs going forward, but don’t worry — you’ve got this!

And remember, if you ever need advice or an answer on the next new 3-month-old baby development, even in the small hours, the mamas on Peanut have got your back.

🤰 Read next: 4 Month Old Baby: Milestones & Development