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Infant development is most often divided into the following areas:

  • Cognitive
  • Language
  • Physical, such as fine motor skills (holding a spoon, pincer grasp) and gross motor skills (head control, sitting, and walking)
  • Social


An infant’s physical development begins at the head, and then moves to other parts of the body. For example, sucking comes before sitting, which comes before walking.

Newborn to 2 months:

  • Can lift and turn their head when lying on their back
  • Hands are fisted, the arms are flexed
  • Neck is unable to support the head when the infant is pulled to a sitting position

Primitive reflexes include:

  • Babinski reflex, toes fan outward when sole of foot is stroked
  • Moro reflex (startle reflex), extends arms then bends and pulls them in toward body with a brief cry; often triggered by loud sounds or sudden movements
  • Palmar hand grasp, infant closes hand and “grips” your finger
  • Placing, leg extends when sole of foot is touched
  • Plantar grasp, infant flexes the toes and forefoot
  • Rooting and sucking, turns head in search of nipple when cheek is touched and begins to suck when nipple touches lips
  • Stepping and walking, takes brisk steps when both feet are placed on a surface, with body supported
  • Tonic neck response, left arm extends when infant gazes to the left, while right arm and leg flex inward, and vice versa

3 to 4 months:

  • Better eye-muscle control allows the infant to track objects.
  • Begins to control hand and feet actions, but these movements are not fine-tuned. The infant may begin to use both hands, working together, to accomplish tasks. The infant is still unable to coordinate the grasp, but swipes at objects to bring them closer.
  • Increased vision allows the infant to tell objects apart from backgrounds with very little contrast (such as a button on a blouse of the same color).
  • Infant raises up (upper torso, shoulders, and head) with arms when lying face down (on tummy).
  • Neck muscles are developed enough to allow the infant to sit with support, and keep head up.
  • Primitive reflexes have either already disappeared, or are starting to disappear.

5 to 6 months:

  • Able to sit alone, without support, for only moments at first, and then for up to 30 seconds or more.
  • Infant begins to grasp blocks or cubes using the ulnar-palmar grasp technique (pressing the block into palm of hand while flexing or bending wrist in) but does not yet use thumb.
  • Infant rolls from back to stomach. When on tummy, the infant can push up with arms to raise the shoulders and head and look around or reach for objects.

Your baby’s growth and development – 1 month old

Infant development begins at birth and they grow fast and learn a lot. At 1 month, cuddling, sleeping and feeding are all that really matters to your baby. The time you spend with them will help their brain to grow and develop as they start to experience the world.

Your baby will probably be crying a lot at the moment. It’s often because they’re hungry or have a dirty nappy, but often babies just cry for no apparent reason. Give them lots of cuddles to comfort them and remember that the crying will eventually pass.

At 6 to 8 weeks, your baby needs a full health review by a health professional such as child and family health nurse, midwife, doctor or paediatrician.

Your 1-month-old

All babies grow at different rates. But on average, at this age they gain between 0.7 to 0.9 kg each month and grow 2.5 to 4 cm. Their head circumference will increase by about 1.25 cm each month.

All babies lose weight right after they are born. Healthy babies usually get back to their birth weight in about 2 to 3 weeks and will then continue to grow.

Your baby was weighed at birth and your doctor or maternal child health nurse will plot their growth regularly on a growth chart. Babies come in all different shapes and sizes, and your baby might be large or small. What matters is that they grow consistently over time. Try not to compare your baby’s weight gain with that of other babies.

What can your baby do?

At 1 month, most of what babies do is still caused by reflexes. They aren’t thinking about their actions. They will be sucking, swallowing, searching for milk and grasping an object if you put it in the palm of their hand (although most of the time they’ll keep their hands clenched in tight little fists). They will also step one foot in front of the other if you put their feet on a flat surface.

They will start to focus with both eyes at 1 month and should be able to follow a moving object from side to side. They will probably prefer looking at a human face to looking at an object and will gaze deeply into your eyes if you hold them about 45 cm away. Most babies can recognise their parents by this age.

One-month-old babies love the sound of your voice, but they will get startled if they hear a loud noise. They might fall backward and throw their arms and legs out, blink their eyes and breathe faster.

By the end of the first month, most babies can raise their head when you lay them on their stomach, and they will turn their head to one side. As their neck muscles get stronger, they will be able to turn their head and lift it up when they’re in a car seat or carrier.

Your baby will cry loudly when they are hungry or uncomfortable. When they are happy and content, they usually make little gurgling noises. Respond to your baby’s sounds by gurgling and cooing back.

At 1 month, some babies will be learning how to soothe themselves, with a dummy or even by sucking their fingers or thumbs. Helping your baby to suck is a good way to calm them down.

How to help your baby develop

Spend as much time with your baby as possible. Looking deep into their eyes and smiling at them will help them to bond and to feel safe and secure.

Read and sing to your baby. Even though they can’t understand, they will enjoy hearing your voice. Music helps to stimulate their senses and will keep them amused. Playing with them will also strengthen your bond.

Help your baby to develop neck strength by putting them on their tummy for 1 to 5 minutes at a time. This is called tummy time. Always keep an eye on your baby during tummy time and always put them to sleep on their back.

Development problem signs

Babies develop at a different rate. At 1 month, you will still be learning about your baby and their needs. But talk to your doctor or maternal child health nurse if:

  • they aren’t feeding well
  • they are regularly sleeping a lot more than 16 hours a day
  • they aren’t moving their arms or legs
  • they aren’t following your face with their eyes or responding when they see you
  • they aren’t making gurgling sounds
  • they don’t startle or seem not be hearing things
  • you are worried about your baby’s crying or sleeping

Your baby’s growth and development – 2 months old

Your 2-month-old is growing fast and becoming more alert. They will be making more sounds and getting more skilled at moving their body. They will still be crying a lot – but you’ve probably already seen that magic first smile (usually at 6 weeks) which somehow makes all the hard work worthwhile.

Your 2-month-old

By 2 months, your baby will have put on a lot of weight and may be looking round and chubby. As their muscles develop, their arms and legs start to move more freely, stretching out to make them seem taller and leaner.

During their first 2 months your baby is growing very quickly. They will keep growing at this rate, probably gaining about 900g and growing 2.5 cm to 3.8 cm every month.

Babies often have a growth spurt at about 6 weeks. This might make them more fussy because they want to eat more than usual. It might feel like you’re feeding all the time, especially at certain times of the day. You can sometimes tell your baby is hungry if they’re sticking their tongue out or sucking. If they doze off or turn their head away, they’re probably full.

At 6 to 8 weeks, your baby will have their scheduled vaccinations – 2 injections and the oral rotavirus vaccine.

What can your baby do?

By 2 months your baby will have discovered their fingers and hands. They will hold their hands open and grab an object (although they don’t know how to let go yet!) They might also clasp both hands together.

Two-month-old babies will start to learn how to coordinate their movements. Instead of the jerky arm and leg movements that made when they were born, they can move more smoothly and in more of a circular motion. They will kick both legs strongly and will be very wriggly. They may even roll over, so don’t ever leave them alone on a change table.

Their neck will be getting stronger all the time. During tummy time they might be lifting their head and moving it from side to side. Some babies can even lift their chest off the ground by now.

Some (though very few) babies can sleep through the night by the time they reach 2 months. But even if you’re not one of the lucky parents or carers, your baby will at least be sleeping for longer stretches at a time. They’ll probably be having 2 to 4 long sleeps and will be more awake and alert during the day – although babies’ sleep patterns still vary widely at this age.

Your baby’s eyes, which may have been crossed when they were younger, move together most of the time now. They will clearly recognise you, will look at you when you talk to them, and can follow you with their eyes. They will love looking at your face and will be giving you some lovely smiles. They will like looking at objects with more complex patterns and colours.

They will also be making a lot more sounds and gurgling, including sounds like ‘a’ or ‘o’, and they will seem to listen to you and talk back to you.

How to help your baby develop

As your baby develops more of a rhythm, you’ll find they are awake more during the day. This gives you more time to interact with them and help them develop. Spend plenty of time reading to them, singing, and talking. That way they’ll get used to sounds and words and will start to develop language and communication skills.

You can play with them by letting them look at and feel a variety of objects with different designs, colours, and shapes. Plastic toys and soft balls work well.

They will love looking at you, so make sure you smile at them a lot. It releases ‘feel-good’ chemicals in your baby’s body and helps them to feel safe and secure. You could also give your baby a massage to relax them. After a bath is a good time.

Continue with 1 to 5 minutes tummy time to strengthen their neck and upper body. It will help them develop the muscles they’ll need later to sit and crawl. But always put your baby to sleep on their back.

Development problem signs

Babies develop at a different rate. At 2 months, talk to your doctor or maternal child health nurse if:

  • they aren’t smiling by 8 weeks
  • they don’t calm down, even for a little while, when you pick them up to comfort them
  • one side of their body seems to be stronger than the other
  • they’re still holding their fingers in a tight fist
  • sudden noises don’t startle them
  • they aren’t feeding properly
  • they’re floppy or stiff

Your baby’s growth and development – 3 months old

By 3 months, your baby will have formed a strong attachment to you. They will respond to you with lots of smiles, and might even talk back to you in their own way. The worst of the crying should be nearly over, and you can really enjoy your baby as they grow into their own little person.

Your 3 month-old

By the time your baby is 3 months, the fontanelle (soft spot at the back of their head) should have closed. There will still be a soft spot on top of their head. It might seem as if your baby’s head has grown faster than their body. It’s normal – the body will soon catch up.

You will still be getting disturbed sleep at nights, but from 3 months many babies start to ‘sleep through’ (which means sleeping for 5 or 6 hours at a stretch at night). But don’t worry if your baby isn’t doing this – they are all different.

What can your baby do?

By now your baby will be starting to experience emotions and communication. They will respond to different expressions, know your voice and will turn to look for you when they hear you. They may start laughing out loud and look around them in wonder – especially at their fingers and toes.

They will smile at strangers, but they definitely know who their parents are by now. Their brain is growing fast and they will start to recognise people by sight and smell as well as by their voice.

They will be gurgling a lot and trying to respond to you when you talk to them. Their sense of touch is also becoming more sensitive and they will be able to pay attention to things for longer.

From now on, your baby will start to reach out for objects as the muscles develop in their arms and hands. They will try to put things in their mouth, although they can’t quite coordinate their hands and eyes yet, take a long look at objects and shake or rattle them.

Physically, your baby will have better control of their head movements and will start to hold their head up when they’re sitting up. When you give them tummy time, you might notice they roll from their front to their back, lift up their head or push up their chest with their hands.

They will be waving their arms and kicking their legs strongly. If you hold them upright with their feet on the floor or your lap, they’ll probably push down on their legs.

A lot of the time, if they are near a dangling object, they will bat at it with closed fists. However, they can also open their fingers to grasp an object and they will be better coordinated, so they can bring their hands together.

How to help your baby develop

This is the time when the foundations of language are built. Talk and read to your baby as much as possible. It will help them learn how language works and how conversations go back and forth. Respond to your baby with words or with different noises, to encourage them to express themselves.

Choose baby books with large, bright pictures. It doesn’t really matter what the words are, it’s the sound of your voice that counts. Point to things around your baby and tell them the names. If you live in a bilingual home, it’s OK to use both languages to describe the world to your baby.

You can help your baby to develop the muscles in their neck and back by dangling a toy in front of them when they’re on their tummy. Or offer a toy to them to help them learn to grasp it. Stimulate their sense of touch by stroking them with different materials like fur, felt and tissue. Cuddles, massage and moving them through the air will all help to calm them down.

Development problem signs

Babies develop at a different rate. At 3 months, talk to your doctor or maternal child health nurse if:

  • they aren’t smiling by 8 weeks
  • they don’t calm down, even for a little while, when you pick them up to comfort them
  • one side of their body seems to be stronger than the other
  • they’re still holding their fingers in a tight fist
  • sudden noises don’t startle them
  • they aren’t feeding properly
  • they’re floppy or stiff

Your baby’s growth and development – 4 months old

From 4 months, your baby will quickly be learning to coordinate their body. They will have more control over what they do, their vision, touch and hearing will be much more developed, and they will start to move around much more. They can communicate much better too, and the number of hours for which they cry should have settled by now.

Your 4 month-old

Your baby will still be gaining weight steadily – probably about 0.45 kg to 0.56 kg a month. Their bones will be growing fast and they will be getting longer.

Along with their physical growth, 4-month-old babies are learning more about their place in the world. They will be starting to show an interest in solid food and many of their new skills are preparing them for chewing.

Your baby is now due for their next round of vaccinations which will be the same as their first round: 2 injections and the oral rotavirus vaccine.

What can your baby do?

Your baby’s eyesight will be really improving and they will start to link what they see to what they hear, taste and feel. They will pick up objects with their fingers and thumb and will try to put their hands (and everything else!) in their mouth. This is normal and they are teaching their mouth new skills, as well as getting ready for solid food. Just be careful they don’t put anything small enough to fit inside their mouth completely, to avoid the risk of choking.

From 4 months, you baby’s physical skills will really start to develop. They will soon be rolling over, sitting up and some may even start crawling in the next few months.

Now you can really start to have fun with your baby. You can look into each other’s eyes, smile at each other, laugh and ‘talk’. By 4 months, many babies can chuckle and show delight or excitement. They will be showing more emotion and will try to copy sounds like raspberries, ‘ah-goo’ and squeals. They might even say ‘ma-ma’ or ‘da-da’ but don’t get too excited – they probably don’t connect these words with you.

Babies at this age love looking at themselves in the mirror and might smile and talk to their reflection. They can also show emotions like anger and frustration, and might whinge rather than crying all the time. You will get to learn your baby’s cues for being hungry or tired so you can respond to them.

How to help your baby develop

Keep on talking and reading to your baby to help them learn about language and communication. Use different tones and intonations in your voice, or different facial expressions to emphasise the story.

Your baby will love singing songs, reading books, playing with toys and listening to you making funny sounds.

It will help your baby if you develop a routine. If it works for both of you, do things in a similar pattern each day. This will help them to feel safe and secure.

It’s also a good idea to think about preparing your home for when they start moving around. It could happen soon!

Development problem signs

All babies develop at a different rate. At 4 months, talk to your doctor or maternal child health nurse if they:

  • don’t seem interested in things around them
  • don’t seem to know you
  • aren’t making any voice sounds
  • don’t open their fingers
  • don’t kick their legs, or their legs are bent most of the time
  • don’t follow an object with their eyes or make eye contact
  • don’t turn when you speak to them, or they aren’t startled by a loud noise
  • are unhappy or unsettled most of the time

Your baby’s growth and development – 5 months old

Your baby will be growing and developing rapidly now. They are learning more about the world and how they fit into it. Many of the new things your baby is learning at 5 months are preparing them for eating solid food. It is usually recommended you introduce solids at 6 months, but some babies are ready as early as 4 months. So, if you think it’s time, it’s fine to start experimenting with solids now.

Your 5 month-old

By 5 months, your baby’s weight may have doubled from their weight at birth. They will put on about 550g a month now and grow about 2cm in length. But all babies are different. As long as they keep growing as expected according to their growth chart, don’t worry too much about weight gain and try not to compare your baby with others.

Babies like routine because it makes them feel secure. But the routine you had when your baby was smaller might not work so well now – you will need to adjust it to suit their age.

If you haven’t already done so, now is the time to make sure your home is child friendly, since your baby will soon be on the move.

What can your baby do?

Your baby will soon be sitting up on their own. Babies tend to straighten their back when held or propped up in a sitting position. They may even be able to sit for a moment without support, but always stay close by and surround them with cushions in case they fall. When they’re on their tummy, they will extend their arms and legs and arch their back. When they’re on their back, they’ll be able to lift their head and shoulders. They will love bouncing up and down on your lap and can often roll from tummy to back and back to tummy with ease.

They will still be exploring everything with their mouth and can bring an object to their mouth easily now. Even though they may be able to hold a bottle by themselves, it is still best for you to feed them. They will probably be taking a great interest in solid food, though breast milk or formula should still be their main diet at 5 months.

Your baby will be learning lots of language skills at the moment. They may repeat something over and over again, like blowing a raspberry. This is very normal. They can also recognise different sounds and what makes them. This is great for distraction – try jangling a set of keys to grab your baby’s attention if they’re getting fussy at the shops.

At 5 months, babies get good at telling you what they need. For example, they may lift their arms above their head to let you know they want to be picked up, or they may cry when you leave the room. They can laugh and giggle, cuddle and kiss you, and are great fun to play around with. They are also learning about cause and effect – they may keep dropping an object for you to pick up, which they’ll find very funny.

How to help your baby develop

Talk and listen to your baby. Use different tones and facial expressions and respond to the sounds they make. This helps them learn how conversation works and how to express their feelings.

Play with your baby as much as possible, by reading books, singing, tummy time, making funny sounds and giving them toys. Sometimes they may be too tired or hungry to play, but by now you can probably pick up on your baby’s cues so make sure you give them what they need.

Development problem signs

Babies develop at a different rate. At 5 months, talk to your doctor or maternal child health nurse if they:

  • don’t seem interested in things around them
  • don’t seem to know you
  • aren’t making any voice sounds
  • don’t open their fingers
  • don’t kick their legs, or their legs are bent most of the time
  • don’t follow an object with their eyes or make eye contact
  • don’t turn when you speak to them, or they aren’t startled by a loud noise
  • are unhappy or unsettled most of the time

Your baby’s growth and development – 6 months old

Six months is an exciting time and your baby will now be developing very fast. The left side of their brain will have has started communicating with the right side, meaning they can coordinate their body better. You will be understanding your baby much better now as they let you know whether they’re happy or sad and start to respond to words.

Your 6 month-old

By the time they reach 6 months, babies have a much better sense of who they are and how they fit into their world. They will have a good sense of the difference between their parents, siblings and other people, and may even start to be anxious of people they don’t know.

Six months is the recommended age to introduce solid food. If you haven’t already started, you can try offering small amounts of smooth, pureed or mashed food once a day, and still continue breastfeeding or formula feeding. When you are giving your baby solids, you can also offer some small sips of cool, boiled water from a sippy cup. If you have allergies in your family, talk to your doctor or child and family health nurse before you introduce common allergy foods like eggs or cow’s milk.

Your baby is now due for their 6 months check. This is when you and your doctor will discuss sleep patterns, safe sleeping and prevention of sudden infant death syndrome (SIDS), healthy diet and teeth care, growth and safety. Your baby also needs their third scheduled vaccination, which involves just one injection this time.

What can your baby do?

From about 6 months – sometimes a little later – your baby’s hand control will have developed enough so they can grab an object and move it towards them. They might even be able to pass an object from hand to hand and will learn how to let go of something (and to understand that it fell). It’s too early to tell whether they are left or right handed; they will tend to use one hand a lot and then switch to the other.

Most babies can roll over by 6 months, which means you need to be very careful to keep hold of them on the change table or bed. They are starting to push themselves up into a crawling position and may be able to rock back and forth on their hands and knees. They can push up and down with their legs in a standing position and may be able to sit with support. They will often be able to turn themselves in the direction they want to go by now.

Six-month-old babies love interacting with you and will start to let you know what they want. They are learning how to attract your attention in ways other than crying. They will also start to understand your emotions from the tone of your voice, for example if you speak to them harshly. Some babies at this age can understand a few words, like “bath”, and can recognise their own name.

Their communication skills will be developing fast. You will be hearing lots of babbling, singing, squeals and bubble blowing, sometimes referred to as ‘vocal play’. They love language games and understand how to take turns as you ‘talk’ to each other. About half of 6 month-old babies can repeat a sound over and over again (“babababa”). Some will even combine several sounds together (“baga”). Mimic the sounds back to them to help them learn to talk.

How to help your baby develop

Your baby will love exploring the world. Surround them with safe things they can touch and put in their mouth, like a soft ball, different fabrics, teething rings or bells.

Talk and listen to your baby, looking them straight in the eye, making facial expressions and responding to their sounds. They will love being read to, especially books with bright pictures. Have a cuddle while you read to them so you can enjoy this special time together. Reassure them when they’re with people they don’t know, to help them feel safe and secure.

Start introducing solid foods to your baby now. This is important to give them the nutrients they need, including iron, but also to strengthen their jaw to help with chewing food and talking.

If you haven’t done so already, now is the time to baby proof your house. Your baby will soon be on the move so make sure their environment is safe.

Development problem signs

All babies develop at different rates. At 6 months, talk to your doctor or maternal child health nurse if:

  • your baby doesn’t seem interested in things around them
  • doesn’t seem to know their parents or respond to people they know well
  • isn’t showing any interest in their surroundings
  • isn’t reaching for objects
  • isn’t starting to babble or make any voice sounds
  • doesn’t make eye contact
  • can’t be comforted by a parent or a close carer


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