3-Month-Old Baby — Development Milestones, Sleeping, And More

by Team Scary Mommy
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3 month old baby
Stefka Pavlova/ Getty Images

It’s hard to believe, but you now have a 3-month-old baby. Time flies when you’re having fun with your little one, huh? This is an exciting month for you and for baby, because important things are starting to take place. Patterns are becoming more established, baby is showing more personality and, as you know all too well by now, they seem to grow bigger and look different every single day.

You’re probably taking a million pictures of your little nugget, as you should be. Mark these moments now because your 3-month-old will change even more over the course of the next few months. For now, soak up every second! And so you’re not spending too much precious time worrying about what’s normal and what’s not, here’s an easy-to-follow briefer on the sort of development milestones and more to expect from your child this month.

Your 3-Month-Old Baby’s Development & Growth Milestones

How much should a 3-month-old weigh?

Your cutie is probably starting to fill out and may even look like a chubby little cherub. But how much should a 3-month old baby weigh? According to the World Health Organization, the average weight of a baby girl at 3 months is 12. 9 pounds and a baby boy at 3 months is 14.1 pounds. Every baby is different and being higher or lower than this benchmark probably isn’t cause for concern as long as the disparity isn’t dramatic. If you’re worried your 3-month-old is gaining weight too rapidly or isn’t putting on enough, by all means, give their pediatrician a call.

How much do you feed a 3-month-old baby?

Your little chunker packing on weight each week comes with a few noticeable changes to your typical routine. For instance, you may notice baby will drink more milk during each feeding and may not feed as often. So, longer feedings but less frequently. Which leads us to the words you may feel like you’ve been waiting forever to hear — as baby gets bigger, they may start sleeping through the night (if they aren’t already).

If you’re breastfeeding, baby probably takes most of the guesswork out of how often you should feed your 3-month-old baby, as they’ll let you know when they’re hungry and, subsequently, when they’re full. If you’re formula feeding, baby may still be taking 4 to 5 ounces around six to eight times a day as they did during month 2. But don’t be surprised if that bumps up by about an ounce at each feeding this month.

Can I give my 3-month-old food and water?

At this point, the answer to both is still typically no. Most doctors recommend baby only consumes breast milk and/or formula up to 6 months in age. Their liquid diet gives them all of the sustenance and hydration they need. However, some babies may be ready for solid foods by around 4 months of age, meaning infant-friendly foods like baby cereal could be just around the corner.

How much should a 3-month-old be sleeping?

Since it probably sounds like music to your ears at this point, it bears repeating: At 3 months old, your baby may start to sleep through the night. So, you (and baby) might get roughly seven to nine hours of sleep straight. Praise be to the gods of slumber!

According to the National Sleep Foundation, babies typically sleep 14 to 17 hours through this month. Granted, there isn’t really such a thing as 3-month-old bedtime as their sleep schedule can be unpredictable at this point. That means baby might be snoozing from 6 p.m. at night to 3 a.m. the next morning. But hey, you’ll take what you can get, right? FWIW, baby probably also sleeps between 4 to 5 hours per day, typically split between a few naps.

And just because baby doesn’t necessarily adhere to a sleeping schedule yet doesn’t mean you should give up on it altogether. Practicing a consistent routine can help ensure both you and baby get in as much quality shut-eye as possible.

Your 3-Month-Old Baby’s Physical, Social, And Cognitive Milestones

How much can a 3-month-old baby see?

Don’t be surprised if you’ve already received a tiny headbutt or two from your little squeaker. Although baby’s vision is actually increasing this month, they still lack depth perception. In other words, they have no idea how far away (or close) objects are to the. They can very clearly recognize objects 8 to 15 inches away, though. Unlike last month, they should be able to focus on your face now without going cross-eyed. Per the Centers for Disease Control and Prevention (CDC), baby should be able to follow objects through a full 180-degree angle at 3 months old.

Is my 3-month-old teething?

If you notice your 3-month-old seems fussy and is drooling a lot, well, it might just be more concrete evidence they are, in fact, a baby. But it’s also possible your 3-month-old is teething. According to the Mayo Clinic, babies often begin teething by about 6 months of age. But you know how it goes with babies — they’re all different (take it from a mama whose child looked like a Mako shark at 4-months-old). Curious what to look for? In addition to the crankiness and drooling, baby might be chewing on everything, have sore gums, and be running a low-grade fever.

As for how you can soothe your teething 3-month-old, there are a few things you can do to help baby during this frustrating time. Baby loves to chew on your fingers anyway, so you can always (after washing your hands well) rub your little ones’ gums with a clean finger. You can also try chilling a clean, damp washcloth or teething ring in the fridge or freezer and letting baby chew on it. If baby seems particularly miserable and the fever persists, you can give them an over-the-counter remedy like baby Tylenol.

How alert should a 3-month-old be?

At 3-months-old, baby is in an adorable stage during which they seem more alert than ever. Baby should be able to hold their head up at a 90-degree angle. They may even be able to sit up and hold their head fairly steady with a little support. Your little angel might be standing up and bearing weight on their legs (or, if you’re currently in baby talk mode, wittle weggies) while supported by you. Better hearing clarity and increased vision mean baby is going to be more aware of what’s going on around them — recognizing more objects turning toward noises and starting to imitate speech sounds.

How do you play with a 3-month-old baby?

Your 3-month-old baby opens and closes their cute little hands now, meaning they’re probably exploring fun new tricks like grabbing and shaking toys. So, when you’re trying to decide what other 3-month-old-approved baby toys to bring into the house, think about ones that rattle or crinkle. Baby will also be drawn to bright colors and interesting patterns. And since baby’s hand-eye coordination is getting better by the minute, a baby gym that let’s them tug on dangling items and swat at others will surely be a hit. Bonus? This tummy time could lead to baby learning to roll over from front to back.

Your 3-Month-Old Baby’s Health

Does a 3-month-old need a checkup and immunizations?

Good news — for the first time in what probably seem like a really long time, you likely won’t have to make the trek to see your child’s pediatrician. Of course, how often you visit the doctor in your baby’s first three months really depends on their overall health, but typically your baby will have routine checkups at 1 month old and 2 months old and then again at 4-months-old. So, baby should get a reprieve from shots this month, yay!

This is a good time to make sure you have your baby’s 4-month-old baby checkup scheduled, if you haven’t already.

How often should a 3-month-old poop?

Who knew you’d ever be so interesting in poopy diapers? Add it to the ever-growing list of things you never thought you’d wonder until you became a parent. At three months old, babies typically still have at least one bowel movement per day. But don’t be surprised if they skip a few days (and then, sorry ’bout your luck, have an epic blow-out at some point).

Curious about what color poop a 3-month-old should have? It varies. Per the Mayo Clinic, yellow, mushy bowel movements are perfectly normal for breastfed babies — as are yellow-green bowel movements and seedy, light-mustard-colored ones. Formula-fed 3-month-olds might have yellow or tan BMs with hints of green and may be more firm than breast-fed BMs. Baby’s BMs shouldn’t be any firmer than peanut butter.

Does a 3-month-old have a growth spurt?

Does your baby seem especially hungry or fussy? They might be experiencing a growth spurt! In addition to increased hunger and fussiness, baby might be more restless at night, waking up more — possibly for “cluster feeding,” aka more frequent feedings. Typically, these side effects of a growth spurt are temporary. If baby wants to eat, sleep or snuggle more, let them. If the behavior persists, consult baby’s pediatrician at their next checkup.

Written by Julie Sprankles.

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