3 Months Old Baby: A Development and Milestones Guide

You now have a 3 month old baby! Where did the time go? Wasn’t it just yesterday that your baby was born? Now that your little one is three months old, they are no longer considered a newborn baby and is now called an infant. 

Your little one certainly has come a long way but still has lots to learn. With the right care and the correct information, you’ll be amazed by your baby’s growth and development this month and in the months to come.

From their physical, cognitive, social, speech and health, we’ve made a comprehensive guide to keep track of your little tot. Here’s what to expect from your 3 month old baby. 

3 Months Old Development and Milestones: Is Your Baby on Track? 

3-Month-Old Baby: Physical Development

Now that your infant is more versed in moving their hands, they will begin exploring the world around them with their hands and fingers. Your baby will be touching, feeling, and grabbing many things. They will even become more aware of different people around them and use their sense of smell to tell the difference between the people they know and strangers.

Physically, your baby is looking more like a chubby cherub now. The head and body seem more proportionate, and you’ll start to see cute rolls on those adorable thighs and arms. 

At this stage, your child’s median length and weight* should be as follows: 

• Boys
  – Length: 61.4 cm (24.2 inches)
  – Weight: 6.4 kg (14.1lb)
• Girls 
  – Length: 59.9 cm (23.6 inches)
  – Weight: 6.0 kg (13.3lb)

And your child’s head circumference* should be:

• Boys: 40.5 cm (15.9 in)
• Girls: 39.5 cm (15.6 in)

Three months may not be long, but your little infant is growing much faster than you imagine. For instance, your 3-month-old baby can now not only move their arms and coordinate how to move their hands by sight but also has enough muscle strength to support their head.

In particular, your little one should be:

• Gaining better upper-body strength, especially in their neck muscles and during tummy time (or when they are lying down on their front). Your baby should be able to support their head and chest with their arms and learn how to do mini push-ups in due time. 
• Gaining lower-body strength. By the end of this month, your baby should be able to stretch out their legs and kick easily while lying down on their tummy.
• Improving neck strength and control – there is little to no head wobbling when you hold your baby upright.
• Able to have basic hand-eye coordination, such as opening and closing their hands, bringing them together, and swiping at bright-coloured dangling toys in front of them.
• Able to bring their hands closer to their mouth. Your baby can now bring their hands towards their mouth, sometimes even after grabbing a toy. What’s more, your child can even blow bubbles and have some bubbly fun! Do remember to give them baby-safe, age-appropriate toys without small parts, though. Small toys may be accidentally swallowed or act as a choking hazard. 
• Roll on their back. In a few weeks, your bub may begin to have the ability to roll onto their tummy when they’re placed on their back. Do be careful when you are changing your baby’s diaper or if you are playing with them on your bed.

You’ll also be glad to know that it’s not just movement that your infant is capable of. Their developing senses enable them to begin understanding the world a bit better, especially their sense of:

• Touch. At 3 months old, your infant is becoming more aware of the things around them.  Your baby will be interested in touching and feeling different textures. Other than bringing things into their mouth, your baby will learn to bring their hands together in a week or so. Kids this age might even start batting at the toys which they grab!
• Sound. In a few days, your baby should be able to respond to the sound of your voice, turning their head and smiling at you. They will also start to show their love of listening to all kinds of music and will turn toward loud sounds!
• Sight. Look at your baby. It’s likely that they will maintain eye contact by staring right back into your eyes. Your baby already probably knows your face and definitely your scent, mummy! They might also even enjoy gazing intently at their own reflection in the mirror.

How to support your 3-month-old’s physical development

• Give baby some brightly coloured toy rings, rattles or other age-appropriate toys for them to reach out to. Watch as they stretch out to grasp it in their hand (and most likely bring it right into their mouth!).
• Provide your little one with an assortment of textures to touch, such as soft velvet, fluffy cotton, smooth leather, bumpy corduroy and more. They will learn what different textures are while also learning how to use their fingers and muscles.
• Try gathering various things with pleasant scents, such as flowers, spices, or cookies and pass them under your baby’s nose one at a time to see which smells they prefer.

Consult a doctor if your baby:

• Doesn’t grasp and hold objects.
• Cannot support their head well.
• Doesn’t reach for and grasp toys.
• Doesn’t bring objects to their mouth.
• Has difficulty moving one or both eyes in all directions.
• Often crosses their eyes (although occasional crossing of the eyes is normal in the first few months).

Cognitive Development

Three months after birth, your little bub is beginning to understand the world around them. Your baby’s developing brain is working hard to make sense of reality. 

They are getting a better understanding of cause and effect, more often than not batting a dangling toy – which causes it to move. Your baby will start to understand the basics of cause (batting a dangling toy) and effect (causing it to move) in things. Their brain will make thousands of connections as they concentrate on this new skill.

At 3 months old, your baby is also much better at tracking moving objects. Your infant’s eyes should work together to move and focus, especially when something is moving in front of them, such as a toy or your hand. 

How to promote your 3-month-old’s brain development

• Give your little one a head start on learning about different body parts. Take a plushie or stuffed toy and tell your baby the names of each body part. 
• “Beep” them. Make diaper-changing a fun activity by poking different body parts of your baby while saying “beep!” Your little one will become more aware of your hand and even anticipate touch.
• Chat with your baby. Always talk to your little one using simple words and sentences of up to five words, even though they can’t understand you yet. They love listening to your voice!
• Constantly provide your baby with a variety of activities. You can also divert their attention to something else or put them in a different room so they have different things to look at.

Consult a doctor if your baby:

Social and Emotional Development

Even though your little bub hasn’t attended preschool or met their peers, they are smart enough to understand how to interact with others from your social cues, mum and dad!

You’ll notice that your baby is more open to smiling at other people. Your baby’s sweet smile is no longer exclusively reserved for mummy and daddy now! They will begin to be more generous with their grins towards anyone who flashes them a smile first.

Your 3-month-old baby’s personality is starting to show as they get more curious and friendly about others. Your bub will begin to become fascinated by the other babies around them or even their own reflection in the mirror. 

They are also trying to understand emotions and communication. Your little one will begin to link your words to your facial expressions.

How to nurture your 3 month old’s emotional development

• Show your little one pictures of family or friends (even other people in magazines are good), and show them people who are smiling. 
• Return your baby’s gaze and also talk to them softly. Try to imitate the baby’s reactions and the noises they make. 
• Show the baby their reflection. Place a mirror in front of the baby. Tap your little one’s reflection and say their name. Eventually, your little one will know who the reflection in the mirror is.
• Sing to your baby and play them music. 

Consult a doctor if your baby:

• Rarely smiles at other people.
• Does not smile at the sound of your voice.
• Does not pay attention to new faces, or seems very scared of new faces or surroundings.

Speech and Language Development

Rejoice, mums! Your 3 month old baby is learning to interact with other people in ways other than crying.

At this stage, crying will no longer be your baby’s main method of communication. Within the coming days, they will start to express themselves in other ways, like cooing, gurgling, squealing and making vowel sounds, such as: Oh, Ooh, Ah. 

How to encourage your 3 month old’s speech and language development:

• Engage in baby talk. The more you talk to your little one, the sooner they will be able to start forming their own sounds and even making their own gestures when trying to communicate with you.
• Read aloud to them. Your little one may not understand the words you’re saying, or even read. Yet, reading aloud to your infant, no matter how young they are, will help them get familiar with different sounds, words and languages . It will also introduce the value and joy of books to them. Choose baby books with bright pictures to capture your little one’s eyes, too! 

Consult a doctor if your baby:

• Does not gurgle or coo.
• Cries inconsolably for long periods.

Health and Nutrition 

3-month-old baby feeding schedule

A 3-month-old baby’s feeding schedule typically involves frequent feedings throughout the day and night. At this stage, most infants still require breastfeeding or formula every 2 to 4 hours, amounting to about 4 to 6 feedings per day.

Contrary to popular belief, babies at this age should not start solid food yet. Studies have shown that introducing solid food too early is harmful to your little one at this age. Continue breastfeeding as your breastmilk has all the nutrition your 3-month-old baby needs. If you cannot breastfeed for any reason, then the only alternative should be formula milk. 

Babies may show signs of hunger, such as rooting or sucking on their hands, to indicate they are ready to eat. It is important to ensure the baby is properly latched during breastfeeding or prepare the formula according to the manufacturer’s instructions

Baby boys need around 644.6 calories a day. Baby girls need around 609 calories daily. Typically, the amount of breastmilk/formula milk for your baby at this stage is:

• Breastmilk: 19.3-30.4 ounces/day
• Formula: 24 ounces/day

As your baby does not have a mature digestive system yet, it is likely that they will not be able to process or digest solid food. Introducing solids too early can also lead to obesity, trigger possible allergic reactions, cause digestive problems, or even be a choking hazard which can potentially be fatal.

Babies are generally ready to have solids when they are six months old. Your breast milk offers your 3 months old baby all the nutrition they need. 

3-month-old baby sleep schedule

Also, do remember that growing babies need not just food to nourish their bodies but also enough sleep. Some babies might be sleeping for longer at night by this age. But then again, every baby develops differently. So it’s okay if your little one has not yet reached this particular sleep milestone. 

It is important to note that babies at this age are still establishing their sleep patterns. Most infants require about 14 to 17 hours of sleep per day, including both daytime naps and nighttime sleep. However, their sleep tends to be fragmented, with periods of wakefulness throughout the night. It is common for babies to wake up every 2 to 3 hours for feeding or comfort.

Establishing a consistent bedtime routine can be beneficial in promoting better sleep habits. This may involve creating a calm and soothing environment, engaging in quiet activities before bed, and providing comfort to the baby if they wake up during the night.

It is essential to prioritise safe sleep practices, such as placing the baby on their back in a crib or bassinet with no loose bedding or soft objects.

How to support your 3-month-old baby’s health:

• You don’t need to give your 3-month-old baby water if you are still breastfeeding. On hot days, increase the frequency of nursing. 
• Ensure the baby drains each breast during each feed so that they get the calorie-rich hind milk. 

Consult a doctor if your baby:

• Is severely under or overweight.
• Throws up excessively after each meal. 

Vaccination and Common Illnesses

At 3 months old, your baby should get the following vaccinations:

• DTaP – 1st dose: Immunisation against Diphtheria, Pertussis & Tetanus
• IPV – 1st dose: Immunisation against Poliomyelitis
• Hib – 1st do​se: Haemophilus influenza type b vaccine
• Pneumococcal Conjugate – 1st dose: Immunisation against Pneumococcal Disease

Your baby’s immune system is still very immature. This combined with an incomplete vaccination schedule makes them very vulnerable to common illnesses like the common cold. Other common illnesses are: 

• Respiratory Syncytial virus, which has symptoms like runny nose, nasal congestion, and heavy breathing 
• Hand, Foot and Mouth Disease may present itself via fever and sore throat, with some rashes on the palms, soles, trunk and diaper area.
• Scarlet fever has symptoms including a sore throat and red rash around the neck and face. 

While these conditions may not be a big deal in an older child, in a young baby, they could lead to even more severe consequences.

This is why it’s crucial you and all others who handle your baby practice strict hygiene, which must include frequent hand-washing. Wear a mask if you have a cold or cough, and any other family members or friends with colds or who are sick should stay far away from the baby until they are better. 

Nobody should ever kiss your baby on their face, mouth, hands or feet, as this could potentially transmit the fatal HPV virus to your little one. 

Treating Common Illnesses 

If your little one gets a cold or other common illness, you should bring them to the paediatrician immediately. At just 3 months old, your baby is too young for any kind of home remedies. 

Note: Never give your baby medicine not prescribed by a paediatrician.

A good way to pacify your baby during vaccinations is to breastfeed them while he’s getting the jabs.

Some babies develop a fever after vaccinations – speak to the doctor about the best way of managing this. 

While your baby’s immune system is getting stronger by the day, it’s still not fully developed. Avoid bringing them into crowded places; other people should always wash their hands before touching or carrying them. 

Consult a doctor if your baby:

• Has a suspicious rash 
• Displays noisy or laboured breathing
• Has a sudden loss of appetite
• Has a fever of 37.8 degrees Celsius or higher
• Shows symptoms that persist over a few days, such as diarrhoea and coughing

While different babies develop at a different pace, there are certain milestones your 3 month old baby should reach this stage. If you are worried about your infant’s development, consult your child’s doctor as soon as possible.

What Is the Sleep Schedule for 3 Month Old

The sleep schedule for a 3-month-old baby is going to be different for every baby. Some babies will sleep through the night at this age, while others won’t be able to do so until they’re 6 or 7 months old.

Your baby’s sleep schedule is going to vary pretty wildly during the first few months of life. As a general rule, though, you can expect to see your little one sleeping for about 14 to 17 hours a day (24 hours).

Babies tend to wake up from their naps around the same time every day, so if your baby wakes up at 6AM, you can expect them to wake up at 6AM every day for several weeks. After that, their routine might change slightly—or even drastically!

Don’t worry about it too much! It’s normal for babies to have unpredictable schedules in their first few months. Just do your best to keep track of what time you feed your little one and what time they go down for their nap. If they’re still waking up early or not waking up at all, try feeding them earlier or later than usual.