4-Month-Old Baby
Life for a 4-month-old baby is all about playtime! Baby’s laughing and reaching—and doing tons of gnawing. While you two play on the floor, baby is probably showing off some newfound athletic abilities, such as rolling over and pushing up.
As baby gets older, you’ll notice they’re hitting their fair share of 4-month-old baby milestones. This is the stage when your little one will start showing more interest in interactive play, and there’s a good chance they’ll start teething soon too. While you’re quickly becoming a rockstar in your role as a caregiver, you probably still have some new questions: How much should a 4-month-old eat? What’s the right 4-month-old sleep schedule? Is the 4-month-old sleep regression inevitable?
Feeling overwhelmed? We’ve got the info you need to help keep your 4-month-old baby happy and healthy.
- Yes, the 4-month-old sleep regression is real. Don’t lose hope—you can get through it! The key is establishing a nighttime routine for baby.
- At this age, some babies are ready for solid foods. Make sure to watch for signs of readiness and talk it over with baby’s pediatrician.
- At 4 months old, baby may be rolling from stomach to back. Keep encouraging these movement milestones!
How much should a 4-month-old baby weigh and measure? The average weight for a 4-month-old baby is 13.8 pounds for girls and 15 pounds for boys; the average length (aka height) is 24.2 inches for girls and 24.8 inches for boys.
Of course, that doesn’t mean your 4-month-old should weigh and measure exactly that. Remember: Healthy babies tend to follow a natural growth curve, staying within the same percentile as they grow older, and it’s the growth itself that’s an indicator of healthy development—not the actual percentile. Either way, baby probably has gained an extra 1 to 1.25 pounds in the past month.
Your 4-month-old continues to grow and learn new skills. It’s an exciting time, and you’ve got a front-row seat for all the 4-month-old moments and milestones. “What should my 4-month-old be doing?” you ask? Here’s a peek:
- The 4-month-old baby milestones are exciting for you and baby. At this age, they may start holding their head up without support and grasping toys on their own. Baby is getting stronger every day, and you’ll start noticing some serious progress.
- Baby may be able to roll from their stomach to their back and push up to their elbows.
- Baby loves to reach for toys! Plastic keys, teething rings and soft books are good choices at this age.
- For a 4-month-old, teething may have begun, which means you’re probably finding drool on everything baby touches!
4-month-old sensory development
Your 4-month-old baby is learning about the world through all their senses. At this stage, there’s a lot going on:
- Baby’s bringing their hands to their mouth and feeling objects with their mouth too.
- They’re listening to you talk and imitating you; you’re probably having little “chats.”
- You can hear baby’s sweet laughs now. Play peekaboo and make funny faces to get baby giggling.
- Baby’s beginning to develop depth perception.
“The postpartum journey can be challenging for women—their mind, body and life has drastically changed forever. We’re flooded with media images of women going back to their exact same pre-pregnancy body immediately after delivery, which is either falsified or unhealthy! Many women are eager to get back to hobbies and workouts they enjoyed prior to pregnancy, but there’s a safe and smart way to do this. Every patient is different, but I strongly encourage my patients to get out and walk whenever they can. It’s important to gradually ease back into exercise regimens or classes and to always listen to your body!” — Kylie Fuller, MD, ob-gyn, Pomona Valley Hospital Medical Center in California
Having a baby seems like a never-ending search for answers to health questions. Here are some common topics parents want to know about at this stage:
Teething
Baby’s first tooth might come in as early as 4 months or as late as one year, but it often emerges around 6 months. When it does, you’ll likely know. Since the process can be uncomfortable, baby might become irritable, cry, eat less or develop a low fever. To help ease any pain, give them something to chew on that’s not a choking hazard, like a cool rag or firm rubber toy. Or, if they’re still cranky, you can try the age-recommended dose of Tylenol. Watch out: The FDA recommends avoiding homeopathic teething tablets, medications with benzocaine and amber teething necklaces.
Belly issues
At this point, it’s common for babies to develop acid reflux—along with gas pain, diarrhea or constipation. When acid reflux happens, stomach acid comes back up their esophagus, causing a burning sensation and spitting up. Although this is usually not a cause for concern, call your pediatrician if baby develops diarrhea that lasts for days or comes with vomiting or a fever of 100.4 or higher. And yes, we know the extra laundry’s a drag—rest assured that this too shall pass.
Thrush
White, velvety sores in baby’s mouth or on their tongue can be a sign of thrush, a type of yeast infection. Common in infants this age, it’s typically transmitted during breastfeeding and happens more often when you or baby have taken antibiotics. Although thrush often goes away on its own, you can treat baby’s mouth with antifungal medicine and your nipples with antifungal cream.
Adding cereal to baby’s bottle
Especially if baby isn’t sleeping through the night, you might be tempted to add cereal or other solids to their milk or formula to help them sleep. But don’t be tempted by this outdated advice. Not only is there no evidence that it’ll help your little one sleep longer, but it could also cause choking.
Checkup and vaccines
At your four-month checkup appointment, your pediatrician will perform a physical exam and measure baby’s weight, length and head circumference. They’ll also give your little one their second round of vaccines, including DtaP, Hib, polio, pneumococcal (PCV) and rotavirus. Plus, they might ask developmental questions, like whether baby has started cooing and babbling or responding to loud sounds yet.
Just when it feels like you’ve gotten into a rhythm with feeding your 4-month-old, things might switch up a bit. Change is the name of the game in this whole parenting gig! Some things, of course, don’t change: You should continue to feed baby breast milk or formula (or both). But what you might really want to know is: Can I give my 4-month-old baby food? The answer is…maybe.
Different babies are ready for solid foods at different ages. Talk it over with baby’s doctor. Before you chat, look out for these signs of readiness:
- Baby holds their head up high and for long periods of time.
- Baby can sit upright (while propped) in a high chair.
- Baby’s interested in food and opens their mouth to try to taste it.
- Baby has lost the extrusion reflex and will no longer push everything out with their tongue.
- Baby lets you know when they are full by pushing the bottle or breast away.
- Baby is staring you down and trying to grab the food you are eating.
Once you decide to start, you’ll have to choose a first food for baby. Avocado, bananas, sweet potatoes and single-grain baby cereal are all popular choices. Wondering how much cereal (or fruit or veggie) for a 4-month-old is appropriate? You’ll have to start slow. Just one or two ounces once a day is plenty for now; if baby doesn’t seem interested in finishing, don’t force it. Introduce a new food once every few days, looking out for signs of a food allergy.
You might be wondering: “Can I give my 4-month-old water?” Note that most experts recommend waiting to give baby water until they’ve reached the six-month mark or once they begin eating solid foods.
How much does a 4-month-old eat?
- Breastfeeding. How often should a 4-month-old nurse? Feedings are still typically about every three or four hours, but each breastfed baby may be slightly different. What’s important is that baby seems content, your breasts seem to have been emptied (they’re soft) and baby’s gaining weight healthily.
- Bottle-feeding. How much formula for a 4-month-old? Typically 4 ounces about four to six times a day.
- Pumping. If you’re pumping breast milk, you’re probably wondering how many ounces of breast milk for a 4-month-old is enough. Baby needs about 25 ounces of breast milk per day. So you’ll need to divide that by how many feedings baby typically has. So if you feed baby about eight times per day, they should get about 3 to 4 ounces of breast milk at each feeding.
To double-check that baby’s getting enough breast milk, you can monitor their diapers. How many wet diapers for a 4-month-old baby is healthy? About four or five very wet ones per day.
Four-month-old babies tend to throw us for a loop when it comes to sleep, switching up how long they’re sleeping and how much they wake up at night—and they may even start to roll over in their crib. Here’s how to handle some common sleep dilemmas at four months.
4-month-old sleep schedule
How much should a 4-month-old sleep? Four-month-olds typically sleep about 12 to 16 hours a day, split between a longer nighttime stretch and two daytime naps.
And for how long should a 4-month-old sleep? Four-month-old babies might wake up during the night—there’s no need to stress, as this is developmentally normal. It’s common for a 4-month-old nap schedule to consist of a morning nap and an afternoon nap that are longer, along with a quick evening nap. Some babies at this age just take two longer naps.
4-month-old sleep challenges
At four months, some parents report that their good sleeper suddenly isn’t such a good sleeper. Or maybe their 4-month-old wakes up screaming more often in the middle of the night than they used to do.
There’s a term for this: 4-month sleep regression. Babies this age don’t sleep as deeply as they used to; plus, their brains are more active, making them more alert. A soothing sleep routine can help baby get back to snoozing more soundly—as can getting baby used to falling asleep on their own in the crib, rather than in your arms (we know this is easier said than done!).
Can you sleep train a 4-month-old?
This is a personal choice, but some experts say you can start sleep training around this time. Looking for signs that baby might be ready for sleep training? If they’ve gotten into a regular sleep routine and dropped most of their middle-of-the-night feedings, it’s probably a good time. Read more about how to sleep train baby to see if it’s right for your family.
Is it okay for baby to sleep on their stomach?
You should be putting baby down in the crib on their back, to reduce the risk of Sudden Infant Death Syndrome (SIDS). That said, if you check the monitor or walk in baby’s room and find your 4-month-old sleeping on their stomach, you’ve got a roller on your hands! Letting baby sleep on their stomach can be a scary notion after you’ve been taking all of these precautions the whole time. But it’s safe to let your little one sleep on their tummy if they got there on their own, if they’re strong enough to lift their head and roll completely over you can feel reassured. Another safety tip: You should stop swaddling baby, if you haven’t already, once they start rolling over.
The four-month mark is a good time to start helping baby establish more of a routine. A 4-month-old’s daily schedule might look something like this:
Four-month-old babies need plenty of downtime, but they like to be kept busy too! Now that you’ve got an active, playful baby on your hands, you’re probably looking for more things to do with your 4-month-old. Check out this list of baby activities that will give you an idea of 4-month-old activities, as well as things to do with baby as they grow. Here are some more ways to keep things fresh and fun:
- Now is a great time to begin introducing nursery rhymes. Sing to baby and encourage them to coo and babble along with you.
- There’s a reason the game “peekaboo” is so popular. As a 4-month old baby matures, they’ll love engaging with you and seeing your silly faces. At this point, they’re probably trying to mimic some of your funny mugs too!
- Try introducing some new colorful toys that show cause and effect. They may start reaching for and grasping toys on their own; solo playtime is just starting to get fun!
Baby’s achieving some exciting milestones—and you’re continuing your postpartum recovery journey. Here are some tips you might want to keep in mind this month.
Postpartum recovery tips
- Dealing with postpartum stretch marks. If you’ve noticed red or purple marks on your skin recently, don’t be alarmed. They’re stretch marks, a type of scarring resulting from your skin stretching quickly to accommodate your pregnancy. Fortunately, they’re extremely common and should fade within six to 12 months. But if they bother you, you can consider treatment options, like laser skin resurfacing, dermabrasion, microneedling and retinol creams (just make sure the method you choose is safe if you’re still breastfeeding).
- Facing postpartum skin changes. Sometimes, your skin can change after you’ve given birth. If you’ve developed brownish patches on your face, you likely have melasma. This common condition results from your skin producing too much melanin (pigment). To reduce symptoms, cut down on sun exposure and wear sunscreen. If you’ve noticed your skin is itchy and red, you could have eczema or dermatitis. For relief, use gentle soaps and apply moisturizer, especially after washing your hands. It’s also common to lose more hair than usual and develop acne during this time. Although all these issues typically disappear on their own, you can see your dermatologist for fixes.
- Encountering mom brain. If you feel like you can’t remember anything, you’re not alone. Many new moms report “mom brain” and it’s completely normal (and will not last forever). In fact, research shows that pregnancy leads to a permanent rewiring of the brain that can actually help you take care of baby. It also doesn’t help that you’re probably pretty sleep-deprived. So be kind to yourself, know that this phase will pass—and try to get as much rest as you can.
4-month-old baby care tips
- Change baby’s diaper often. To prevent diaper rash and keep baby happy, change their diaper every two to four hours plus right after they’ve pooped. Be sure to use wipes that are hypoallergenic and free of lanolin and alcohol, to help avoid irritating their skin.
- Wait to give baby honey. The American Academy of Pediatrics (AAP) advises against the sweet stuff until 12 months old, since it can contain bacteria that can cause botulism, a serious type of food poisoning.
- Try a humidifier. Dry air can irritate baby’s throat and air passages. Unfortunately, the heating systems that keep us warm during the cold months can make the air even drier. By running a cool mist humidifier, you’ll add moisture to the air, which can help keep baby more comfortable. The moisture can also provide relief if your little one has a cough, congestion or sore throat.
- Don’t prop bottles. It might seem practical and efficient to prop or lean baby’s bottle against a surface so you can feed them hands-free—but it’s not a good idea. Since you won’t be monitoring them as closely, you could miss signs of choking. Plus, milk can pool in their mouth, which can lead to tooth decay.
At 4 months old, you’ve come a long way in your parenting adventure. But hearing other parents’ stories can still be a source of comfort—and relief. Let these successes and learning opportunities inspire your own journey.
- Win: “My son will be 4 months soon, and I’ve noticed in the last two to three weeks he has increased the amount of ounces he’s eating from the bottle. I found that if he had a good 6 to 7 ounces before bed he’d sleep almost all night long because he stayed full. Also, once he got better with sleeping independently, I found that he was able to soothe himself back to sleep in the middle of the night.” — SamanthaLeigh89
- Challenge: “The 4-month sleep regression is horrible. My daughter was an awesome sleeper before…then about two weeks ago had a bad night here and there. Around that time, she also became very difficult to get to nap! At nap time she screams if you try and help her get to sleep (swaddle, rock, swing, nurse, paci), but you can tell she desperately needs the sleep! And now, we’re three nights into every-hour wakeup calls. I'm exhausted and, of course, the exhaustion brings on the crying (myself, not my daughter) and just makes everything else that much harder.” — XmasDivine
- Wisdom: “To keep my sanity intact, I swear by a routine, like a mini bedtime ritual. A warm bath, a cozy lullaby and some gentle rocking worked wonders for us. Also, don't hesitate to call in reinforcements. Grandma, a friend, anyone who can give you a breather. Remember, you're doing an awesome job, and it's okay to feel overwhelmed. You've got this!” — sophiawilliams8
“It was important to me to get outside with baby every single day. We have a high-energy dog who loves long walks, and getting out in the fresh air was good for the fur and human babies. No matter the weather, I dressed my baby appropriately, leashed up the dog and headed out for a stroll. Our typical routine was walking early in the day after everyone had breakfast. Long walks are helpful for filling up a wake window, and usually meant my baby would nap well at home after. The smells, fresh air and new sights were incredibly stimulating for him.” — Kylie K., mom of one in Florida
Frequently Asked Questions
When will baby sleep through the night?
That’s a great question, and it’s very different for every baby. First of all, keep in mind that “sleeping through the night” means sleeping six- or eight-hour chunks, not for 12 hours straight. It’s very natural for babies to wake up once, twice or several times each night. That said, by 6 months old, most babies no longer need nighttime feeds and many babies will sleep through the night. By 9 months old, about 70 to 80 percent of babies will sleep through the night.
What are the best toys for a 4-month-old?
To stimulate baby’s senses, look for toys featuring a variety of colors, shapes, textures and sounds. To make sure they’re safe and age-appropriate, check each product’s age guidelines and avoid choking hazards and items with sharp edges. For some ideas, consider teething rings, textured balls, board books, hand puppets, rattles, play mats and soft blocks.
What are the 4-month-old wake windows?
Every baby’s wake windows are unique. But most 4-month-olds will be up for between 90 minutes and two hours at a time. Keeping track of their sleep habits can help you make sure they’re getting enough quality rest.
What should my 4-month-old’s heart rate be?
The number of times the heart beats per minute tends to be higher for children than adults. A normal resting heart rate for a 4-month-old is 80 to 160 beats per minute.
What should I do if my 4-month-old has a fever?
If your 4-month-old has a fever lower than 102 Fahrenheit, you can give them a lukewarm sponge bath or try some Infant Tylenol. Just check the bottle and choose the right dose for their weight. But if their fever is higher, lasts for two days or they have other symptoms (like diarrhea, vomiting or a cough), call your pediatrician. Also reach out to their provider if baby recently got a shot or has a serious medical condition, like diabetes.
Four-month-old babies have emerging personalities of their own. They may begin revealing some likes and dislikes through sounds and facial expressions. What’s more, you might hear the absolutely delightful sound of baby laughter. Enjoy this wondrous phase (sleep regression and all!); your little one is growing up quickly!
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.
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