12 Week Milestones For Baby

At the age of 12-week, many babies and their parents experience a significant transition. Your little one is no longer considered a newborn, and they have successfully finished the first three months of their first year of life. Congratulations! What a remarkable accomplishment this is!

The third month of a child’s life is often regarded as the beginning of a period in which things begin to improve for the family. Some of the less enjoyable aspects of caring for a newborn, such as dealing with colic and constantly having to feed the baby, have become easier. 1 The routines that three-month-olds follow when they sleep have also become somewhat more predictable. 2

However, there are still a lot of challenges that come along with having a child who is three months old, and it’s normal for you to feel exhausted and overwhelmed if you still have those feelings. Let’s take a look at what changes to anticipate once your baby reaches the three-month mark, as well as some helpful hints regarding feeding, sleeping, baby care, as well as health and safety.

Your 12-Week-Old Baby’s Development 

Major Growth for One Important Muscle

You know those cognitive leaps your baby seems to be making? Those are reflected by the growth of their brain, which has grown a whopping 25% in size since birth. (And it’s not done yet: Your baby’s brain will double in size from the day they were born to the first birthday.) Senses that were fuzzy in the beginning, like vision and hearing clarity, are sharpening. They now notice us across the room and hear us down the hall.

Their brains are continuing to make millions upon millions of neural connections. (Amazingly, the number of these all-important neural connections peaks at 2 to 3 years of age!) That development is supported not only by reading and singing and seeing new things and people, but by caring responsive feeding, cuddling, consoling…all of which builds the secure and trusting bond—also called, attachment—that will be the foundation of your child’s feelings of self-worth and ability to make friendships and share intimacy.

Look Who’s Grabby

You may need to rethink dangling earrings for a while. Your baby’s new dexterity skills make them quite skilled at grabbing. And few things are more appealing than your hair, glasses, or other accessories. (They like your face just the way it is, apparently!) 

While your baby is working on reaching and grabbing objects for now, the next task on the to-do list is shaking, rattling, and even throwing the things they manage to hold. You can help encourage these skills by placing colorful toys within your baby’s arm’s length during tummy time or while you sit with them on your lap. By cheering them on, you’re not only giving them some encouragement for their motor skills, but you’re also teaching them about communication and language. Win-win!

Note: Never have hot liquids around when holding your baby. Many parents and infants have been scalded when the baby suddenly lunged and pulled hot coffee off the kitchen table.

If you do get burned, immediately put the area under cold running water (or put a wet towel over the area with an ice cube on the other side, to keep it cool for a few minutes. (Putting ice directly on the skin can cause more damage!) And, of course, call your doctor. 

Your 12-Week-Old Baby’s Health

With Baths, Less Is More

A warm bath is a nice addition to the bedtime routine, a good way to soothe your baby, and even a fun opportunity for play. There can be too much of a good thing, however—at least when it comes to your baby’s sensitive skin. Here’s what to keep in mind about bathing your baby. 

  • The American Academy of Pediatrics (AAP) recommends bathing your baby two to three times per week to avoid drying out your baby’s skin. It’s good to clean their bottoms with a soapy washcloth, every day.
  • AAP also suggests using a recently manufactured baby tub with slip-proof surface rather than an infant bath seat. If you’re using the sink, be sure to line it with slip-resistant linking or a clean towel to prevent Baby from sliding. Always keep one hand on your baby during baths and drain the water immediately afterward.
  • Keep your own bath wash…just for you. Your baby is better off with a mild, unscented soap that is made specifically for babies. (Bar soap is good…less plastic to throw away.)
  • Follow up the bath with a little lubricating oil, like cocoa butter or coconut oil

3 Month Baby Milestones

Please continue to drumroll… Congratulations, your child has successfully completed the fourth trimester of pregnancy! To put it another way, after living for nearly three months, most babies are actually ready to be born at this point in time (some are a little slower and need another month of cuddling to really wake up to the world).

You may have noticed that your once fussy baby is much more content these days as you near the end of the fourth trimester of pregnancy. It’s inevitable that your little one will let you know when they don’t agree with something, especially as they get older and develop more firm convictions. But the ratio of smiles to tears is getting better all the time!

Parenting colicky babies can feel like constantly being on the defensive against triggers: forced to walk—or drive or bounce on a yoga ball—for hours during fussy periods. It can be exhausting. But with that (mostly) behind you now, it’s time for some new, fun activities, like bedtime messages and stories.

At This Age

  • Development: Your baby will start to recognize you from farther distances, and will now be able to start lifting their head and chest up from a belly-down position.3
  • Sleep: More of your baby’s sleep happens at night now, and your baby may start sleeping longer stretches at night—some babies are even sleeping through the night.2
  • Food: The length between feedings has stretched out and you may have a more predictable feeding routine.4

 What Is the Average Cost of a Baby?

3 month old baby milestones and development
 Illustration by Joshua Seong, Verywell

3-Month-Old Baby Development

Many people consider the first 3 months of a baby’s life to be the “fourth trimester.”5 Your baby is doing a tremendous amount of growing and developing then, feeds constantly, is up frequently at night, and wants to be held most of the time. By 3 months, your baby will seem a little more regulated in terms of feeding and sleep, and those evening fussies or colic symptoms will have mostly disappeared.1

At the start of 3 months, though, your baby will likely have another big growth spurt.6 They may want to feed more frequently, may seem generally fussier, and may sleep poorly. But all of this is for a good cause! When your baby has a growth spurt, they don’t just grow larger, but they often have major leaps in development.

One area that will develop more strongly this month is your baby’s vision, as well as their perception of the world around them, says Roya Samuels, MD, a pediatrician in the division of general pediatrics at Cohen Children’s Medical Center.   

“At 3 months of age, your infant should have better eye-muscle control allowing them to track objects,” explains Dr. Samuels. “Improved vision allows your infant to tell objects apart from their backgrounds.”

You may notice that your baby studies objects and faces more scrupulously than before, and is better able to follow objects as they move. If you walk into a room, your baby may recognize you, even before you get close. This will be a very exciting and heartwarming moment for you and your baby.3

Your baby is still growing very rapidly these days, and after their latest growth spurt, they may even be ready to grow into the next size of clothing. You probably have noticed that their face has filled out and their little arms and legs have become chunkier. So cute!

Your baby generally grows about 1-1 ½ inches taller at this age and gains about 1 ½-2 pounds per month. But in about four months, your baby will have doubled their birth weight.4 Keep in mind that these are all estimates. It’s normal if your baby’s growth is a little slower and faster than this. All babies grow at their own rates.

 Everything You Need to Know About the 4th Trimester

3-Month-Old Baby Milestones

Over the next few months, your baby will reach some really exciting, picture-worthy milestones, like being able to sit unassisted, and starting to crawl. Your baby isn’t quite there yet, but their body is getting stronger each day, in preparation.

For example, when you place your baby on their belly, you might notice how much stronger they are becoming. “Three-month-old babies should be able to hold their head up well and while laying on their stomach, be able to push up with their arms to support their chest,” says Thanh-Tam Nguyen, M.D., a pediatrician and medical director at CalOptima in Orange County, CA.3

In addition, you may notice that your baby really begins to work their legs. If you lay them on their belly or back, your baby should start kicking their legs playfully and stretching their legs out. If you try to stand or sit your baby up (while supporting them, of course!), they will push down their feet.3

As you watch your baby develop and check milestones off the list, it’s important to keep in mind that all babies are different when it comes to reaching these milestones. “Development may vary depending on factors such as whether the delivery was early or on-time, if the baby has any medical conditions, and different family situations and environments,” says Dr. Nguyen.

If you notice that your baby hasn’t reached milestones that are typical of 3-month-olds, you should check in with your pediatrician for guidance, he adds.

Additional Behaviors

Here are some other exciting milestones your baby is likely to reach this month:3

  • They will continue to expand and refine their vocal skills, “cooing,” and even starting to babble
  • Babies may be able to hold objects for longer periods of time and may be able to start shaking them
  • They will start to coordinate hand and eye movement more
  • Your baby may begin imitating sounds that they hear
  • They will turn toward whoever is speaking

 Are Your Child’s Motor Skills on Track?

3-Month-Old Baby Food

By 3 months old, babies are still feeding frequently, but not quite as frequently as when they were newborns. Many parents find that they are more settled into a feeding routine, and can more readily predict when their baby will need to eat, and begin to plan their days around this.

Breastfeeding babies still need to feed at least eight times in a 24 hour period, but some babies are still feeding more frequently than that.4 There is a wide range of normal. While breastfeeding, you should let your baby finish one breast before offering the other. Let your baby guide you in this process.

Formula-fed babies may be able to stretch the time between feedings to up to four hours. They generally take about 6 ounces per feeding at this age, but again, this will vary depending on how hungry your baby is.4 Always feed your baby based on their hunger cues.

Only about half of all parents are still exclusively breastfeeding when their babies hit the 3-month mark.7 This is often because parents have gone back to work and find it difficult to keep up with a pumping schedule. It’s important to keep in mind that breastfeeding isn’t “all or nothing,” and it’s possible to combine both bottle and breastfeeding. 

You can talk to a lactation consultant about how to do this, and what the best ways are to keep up your milk supply as you return to work.

 How to Tell if Your 3-6 Month-Old Is Getting Enough Food

3-Month-Old Baby Sleep

Three months marks some significant changes when it comes to sleep. Your baby is still sleeping about 15 hours a day, give or take. But now, they are doing the bulk of their sleep at night, which will come as a welcome relief to parents.2

This means that, rather than sleeping at random times during the day, your baby is starting to take actual naps during the day, followed by longer periods of playtime. All babies are different when it comes to naptime, though, so don’t be surprised if you still have a bit of catnapper at this age.

“Naps are varied—some take 30-minute ones throughout the day, others take two longer ones,” says Gina Posner, MD, a pediatrician at MemorialCare Orange Coast Medical Center in Fountain Valley, CA. “Most take at least two naps a day at this point.”

Three months is also the time that some babies are able to technically start to sleep through the night. But many babies just aren’t there yet, says Dr. Posner. “I wouldn’t expect a baby to sleep through the night, but some do,” she notes.

Keep in mind, too, that “sleeping through the night” has a different definition when it comes to babies. A 3-month-old is considered to be sleeping through if they have slept six to eight hours in a row, even though they may sleep a total of nine or 10 hours a night.2 Still, many babies aren’t even there just yet, and still wake every few hours all night. This is perfectly normal, too.

 Why Your Baby Isn’t Sleeping Through the Night

3-Month-Old Baby Schedule

It may not seem like it, but your baby is rapidly developing their language skills. Your baby has been cooing for a while, but this month, you may start to hear them babble. They may respond with smiles while they hear your voice and may even start trying to imitate the words that you say.3

As your baby starts to have longer stretches of awake time during the day, you can use that time to simply talk to your baby, interact with them, and even start reading books to them. All of these things develop their language and communications skills.

So, talk to your baby as you draw them a bath, and change their diaper. You can even describe what you’re doing with them. Watch and marvel as they listen attentively, even though they probably don’t really know what you are saying.

As for books, select books that are brightly colored, simple, and that give you opportunities to be animated and silly as you read. Baby-friendly books that your little one can grab and play with are even better.

 Storytime: Why You Should Be Reading to Your Baby

3-Month-Old Baby Health and Safety

You won’t have another well visit for your baby until they reach 4 months.8 Of course, you should contact your baby’s pediatrician with any questions you may have between now and then. Importantly, if your baby shows any signs of illness or fever, or if your baby has any kind of accident, you should contact your pediatrician right away.

At 3 months, you know the basics about keeping your baby healthy and safe. But there are a few safety issues that might come up right now for you to be aware of.

Shopping Cart Safety

Now that you are out and about more, you will likely start taking your baby on errands with you. It can be tempting to take their portable infant car seat and place it on the top of a shopping cart, but this is not considered safe. In fact, according to the AAP, shopping cart accidents are one of the greatest dangers to young children, and account for 20,000 emergency room visits per year.9

If you do take your baby shopping with you, it’s best not to place your baby in a shopping cart. Shopping carts can even be dangerous for older children. The AAP suggests that you instead wear your baby in a baby carrier, or use a stroller or wagon. If none of those are possible, it might be best to keep your baby home rather than take them shopping.9

Taking Medications While Breastfeeding

If you are still breastfeeding your baby, you may have questions about what types of medications are safe to take—from cold medications to antibiotics, to medication to treat anxiety or depression. The good news is that, according to the CDC, most medications are safe for breastfeeding parents.7 Even if a medication isn’t safe, there is usually an alternative that is.

Consider discussing options with your pediatrician or a lactation consultant. LactMed, a database sponsored by the National Library of Medicine, is a great resource you can bookmark.10 Most medications you are considering taking are on there, along with information about their safety use while breastfeeding.

 When to Switch From Infant Car Seat to a Convertible One

3-Month-Old Baby Care Basics

Your baby isn’t too messy yet (just wait till they start eating solids!), but caring for a baby involves quite a lot of clean-ups. Let’s look at what to expect this month.


You are still changing a lot of diapers, though maybe not quite as many as before. Your 3-month-old isn’t pooping nearly as much as they did as a newborn. It’s normal if they only poop once or twice a day, and even go a few days in a row without pooping. Your breastfed baby’s poop will still be loose, but formula-fed babies have firmer poops.4

Spitting Up

Your baby probably isn’t spitting up quite as much as they did as a newborn, but it’s normal to continue to spit up sometimes at 3 months. As long as your baby is growing and is a “happy spitter,” you don’t need to be concerned.11 Just make sure to have a good supply of burp cloths on hand.  


Your baby is probably not about to get any teeth just yet, but the teething process may be starting, and it’s normal for drooling to start as early as 3 months.12 Your baby may even start to have a few “drool bubbles.” Drooling is not an issue as long as it’s not accompanied by other signs of illness, like fever or congestion. If your baby is drooling and is having trouble breathing, they may have choked; seek immediate emergency care if this is the case.12

 What to Do About Your Baby’s Drool Rash

What Else to Know About Your 3-Month-Old Baby

Once your baby hits 3 months, you might start to enter the “comparison game” of parenting. If you hear of another 3-month-old who sleeps through the night, but your baby doesn’t—or if you hear of a baby this age who has hit a development milestone before your baby has—you might feel jealous or defeated. You might even start to think that you are an inferior parent in some way.

The idea that all babies are different and unique really is true! Even young babies have their own personality, their own strengths and weaknesses, and their own temperaments. As long as your baby is growing well, is healthy, and is meeting their milestones within a reasonable timeframe, there is nothing to be concerned about. As always, you should follow up with your pediatrician if you think that your baby is experiencing any kind of physical or developmental delay.


  • What can a 3-month-old baby eat?
  • What should a 3-month-old baby be able to say?
  • Can a 3-month-old see the TV?
  • How many naps should a 3-month-old take?
  • How long should a 3-month-old sleep at night without eating?
  • What time should a 3-month-old go to bed?
  • How much should my 3-month-old weigh?

A Word From Verywell

At this stage in the game, many of the congratulatory “You just had a baby!” calls have stopped, and fewer people are probably offering you help with your baby. But just because you are past the newborn phase doesn’t mean you don’t need extra help or a little TLC.

Parenting an infant is a big deal, and really takes over your life. Even though you are past those early weeks when your baby fed around the clock and didn’t know the difference between night and day, you are definitely still “in the trenches” of parenting.

Try to cut yourself some slack, practice self-care whenever you can, and reach out for help when needed. Postpartum mood disorders can present at any time in the first year after you become a parent, so don’t hesitate to reach out for professional help if you are experiencing an uptick in depression or anxiety.14

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