Baby development and milestones: your 3 month old child

Baby development and milestones: your 3 month old child

The first year of a newborn's life is one of the fastest in human development, so what exactly can your tiny 3 month old baby do now?

You now have a 3 month oldbaby! Where did time go? Wasn’t it just yesterday that your baby was born? Now that your little one is three months old, he/she is no longer considered a newborn 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 armed with the correct information, you’ll be amazed by your baby’s growth and development this month, and in the months to come. Here’s what to expect from your 3 month oldbaby. 

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

3 month old

Physical Development

Now that your infant is more versed in moving his/her hands, he/she will begin exploring the world around him/her with his/her hands and fingers. Your baby will be touching, feeling, and grabbing a lot of things. He/she will even become more aware of different people around him/her and will use his/her sense of smell as a way of telling the difference between the people he/she knows 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 appear 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 a long time, but your little infant is growing much faster than you imagine. For instance, your 3 month oldbaby can now not only move his/her arms and coordinate how to move his/her hands by sight, but also has enough muscle strength to support his/her head.

In particular, your little one should be:

  • Gaining better upper-body strength, especially in his/her neck muscles and during tummy time (or when he/she is placed lying down on his/her front). Your baby should be able to support his/her head and chest with his/her 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 his/her legs and kick with ease while lying down on his/her tummy.
  • Improving in terms of neck strength and control – there is little to no head wobbling when you hold your baby upright.
  • Able to have some basic hand eye coordination, such as opening and closing his/her hands, bringing them together, and swiping at bright-coloured dangling toys in front of him/her.
  • Able to bring his/her hands closer to his/her mouth. Your baby can now bring his/her hands towards his/her 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 him/her baby-safe, age appropriate toys without small parts, though. Small toys may be accidentally swallowed or act as a choking hazard. 
  • Roll on his/her back. In a few weeks, your bub may begin to have the ability to roll onto his/her tummy when he placed on his/her back. Do be careful when you are changing your baby’s diaper or if you are playing with him/her on your bed.

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

  • Touch. At 3 months old, your infant is is becoming more aware of the things around him/her.  Your baby will be interested to touch and feel different textures. In fact, other than bringing things into his/her mouth, your baby will learn to bring his/her 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 his/her head and smiling at you. He/she will also start to show his/her love of listening to all kinds of music, and will turn toward loud sounds!
  • Sight. Look at your baby. It’s likely that he/she will maintain eye contact by staring right back into your eyes. Your baby already probably knows your face, and definitely your scent, mummy! He/she might also even enjoy gazing intently at his own reflection in the mirror.
3 month old

Your infant’s eyes will be able to focus better now – all the better to see you, mummy!


  • Give baby some brightly coloured toy rings, baby rattles or other age appropriate toys for him to reach out to. Watch as he/she stretches out to grasp it in his hand (and most likely bring it right into his mouth!).
  • Provide your little one with an assortment of different textures to touch, such as soft velvet, fluffy cotton, smooth leather, bumpy corduroy and more. He/she will learn what different textures are while also learning how to use his/her fingers and muscles.
  • Try gathering a variety of 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 he/she prefers.

When to See a Doctor:

If your child:

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

Cognitive Development

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

He/she is getting a better understanding of cause and effectmore 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 (causes it to move) in things. His/her brain will make thousands of connections as he/she concentrates on this new skill.

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


  • 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” him. Make diaper-changing a fun activity by poking different body parts of your baby while saying “beep!” Your little one will become much 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 he/she can’t really understand you yet. He/she loves listening to your voice!
  • Constantly provide your baby with a variety of activities. You can also divert his/her attention to something else or put him/her in a different room so that /has has different things to look at.

When to See a Doctor:

If your baby: 

  • Does not respond to loud sounds (like a door slamming or car honking).
  • Does not notice his/her own hands.
  • Doesn’t follow moving objects with his/her eyes

3 month old

Social and Emotional Development

Even though your little bub hasn’t attended preschool or met his/her peers, he/she is 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 just mummy and daddy now! He/she will begin to be more generous with his/her grins towards anyone who flashes him/her a smile first.

Your 3 month oldbaby’s personality is really starting to show, as he/she gets more curious and friendly about others. Your bub will begin to become fascinated by the other babies around him/her, or even his/her own reflection in the mirror. 

He/she is also trying to understand emotions and communication. Your little one will begin to link what you are saying to your facial expressions.


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

When to See 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.
3 month old

Loving interaction with your 3 month oldbaby is the best way to nurture his growth.

Speech and Language Development

Rejoice, mums! Your little bub is learning how 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, he will start to express himself in other ways, like cooing, gurgling, squealing and making vowel sounds, such as: Oh, Ooh, Ah. 


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

When to See a Doctor

If your baby: 

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

Your 3 month oldbaby is getting better at expressing emotions.

Health and Nutrition 

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

Baby boys need 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 very likely that he/she 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 around six months old. Right now, your breastmilk offers  your 3 month oldbaby all the nutrition he/she needs. 

Also, do remember that growing babies don’t just need food to nourish their bodies: they also need 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 might not have reached this particular sleep milestone just yet. 


  • You don’t need to give your baby water if you are still breastfeeding. On hot days, just increase the frequency of nursing. 
  • Ensure baby drains each breast during each feed so that he/she gets the calorie-rich hind-milk. 

When to see a doctor:

  • If your baby is severely under- or over-weight.
  • If your baby 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

 You can check your baby’s immunisation schedule by clicking this link

Your baby’s immune system is still very immature. This combined with an incomplete vaccination schedule makes him/her 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, which may present itself via fever and sore throat, with some rashes on the palms, sole, trunk and diaper area.
  • Scarlet fever, which 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 it could lead to even severe consequences.

This is why it’s crucial you and all others who handle your baby practice strict hygiene, that 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 baby until they are better. 

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

Treating Common Illnesses 

In the event your little one gets a cold or other common illness, you should bring him/her 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 that is not prescribed by a paediatrician.


  • A good way to pacify your baby during vaccinations is to breastfeed him while he’s getting the jabs.
  • Some babies develop 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 him into crowded places and other people should always wash their hands before touching or carrying him. 

When to See a Doctor:

If your baby: 

  • Has a suspicious rash 
  • Displays noisy or laboured breathing
  • Has a sudden loss of appetite
  • Has 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 oldshould reach at this stage. If you are worried about your infant’s development, be sure to consult your child’s doctor as soon as possible.


WebMD (Baby Development), WebMD (Childhood Illnesses),  HealthyWA,, CDC

*Disclaimer: This is the median length and weight, and head circumference according to WHO standards)

What can your 3 month oldbaby do right now? Do you have any other fun activities to share with our readers? Tell us by leaving a comment below!

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