About premature baby development

A premature baby’s development typically happens in the same order and over the same period of time as it would have happened in the womb.

But premature babies might have health challenges along the way. They might have delays in growth and development as a result. Very premature babies and premature babies with medical complications are more likely to have developmental delays.

For example, babies born at 32 weeks are likely to grow and develop differently from babies born at 26 weeks. This is because babies born at 26 weeks might have medical complications by the time they get to 32 weeks. They’ll probably take longer to put on weight, learn to feed and be ready to go home.

Here are the changes you can expect to see in your premature baby during their time in hospital.

Babies born before 26 weeks

If your premature baby is born before 26 weeks, they will be very small:

• At 23 weeks, they might weigh about 500 g and measure about 30 cm.
• At 26 weeks, they might weigh about 750 g and measure about 35 cm.

Your baby might have fused eyelids. Their eyelids will open naturally over a week or so. Then your baby might open their eyes occasionally, but they can’t focus. Light or other visual stimuli will be stressful for them. To help with this, your baby’s care team will cover your baby’s incubator. Some neonatal intensive care units (NICUs) dim the lights at various times.

Your baby’s ears and hearing structures are fully formed. Your baby can hear, but they might be very sensitive to noise. Your baby might recognise and be soothed by the sound of your voice, but they can’t respond to you yet.

Your baby’s skin is fragile and sensitive. It can mark and bruise very easily. Your baby might get stressed if they’re handled, stroked or touched too much. Your baby’s care team will tell you when your baby is ready to be touched and held. This might be within 1-2 days of birth.

Your baby might startle a lot, and their movements will be jerky and twitchy. Your baby’s muscles aren’t strong, so they won’t be able to stay curled up. Your baby’s care team will probably use bedding to put your baby in a curled-up position. This is comfortable and keeps your baby warm. It helps your baby conserve energy for growth.

Your baby might have breathing support for several weeks and sometimes months. The part of your baby’s brain that controls breathing isn’t yet fully developed, so your baby might have breathing pauses, lasting a few seconds each time. This is called apnoea. Your baby will have medicine to help with the apnoea until they grow out of it. When the apnoea has gone, your baby can go home from hospital.

Your baby isn’t ready for milk or suck-feeding. At first, your baby will get specially formulated fluid directly into their bloodstream. Over time, your baby will start having small amounts of breastmilk or special formula milk until they no longer need the special fluid and they’re having only milk. Your baby will get milk through a tube placed in their mouth or nose.

Your baby will sleep most of the time.

Our article on touching and holding your premature baby has more information on comfort holding and kangaroo care. And our article on premature baby body language explains what your premature baby’s behaviour is telling you.

26-28 weeks

At 26-28 weeks, your premature baby will put on weight and grow longer. But their weight gain might be slow. This might be because your baby is unwell or because your baby has a carefully staged feeding plan to protect their immature digestive system from infection.

Your baby might open their eyes, but they probably still can’t focus or move their eyes together. Your baby will start blinking. They will also grow eyelashes and eyebrows.

At this age, your baby’s responses to sound might change from hour to hour or day to day. Or they might respond to your voice but get stressed by other noises. Your baby’s responses will give you clues to what they like and dislike.

Your baby’s muscles are still growing, and they’re likely to have twitches and tremors.

Your baby’s skin is fragile and sensitive. But if your baby is well enough, you’ll be able to start skin-to-skin contact or kangaroo care.

Your baby will probably need breathing support.

Your baby might start to make sucking movements, but they can’t suck to feed. Suck-feeding from the breast or bottle usually starts only when babies can breathe without support. To safely suck a feed from the breast or bottle, your baby will need to know how to suck, swallow and breathe in the right order.

Your baby’s sleep and wake cycles aren’t clear, but your baby might have both active and quiet periods, as well as very brief alert times.

28-30 weeks

Your premature baby is starting to close their eyelids tightly if it’s bright, but they can’t move their eyes together very much. It’s good to limit bright light around your baby.

Your baby will respond to pleasant sounds and be sensitive to other sounds. They might be quiet and attentive to your voice and might even seem to ‘wake up’ when they hear you. You can talk or sing to your baby during their short alert times. Try to keep stimulation to one thing at a time – for example, eye contact or talking, but not both at once.

Your baby might move and stretch more actively as their muscle strength improves, but they’ll need to be well supported with bedding and positioning.

Your baby might be sensitive to touch, but they’ll like steady, gentle, hands-on touch or skin-to-skin contact.

Your baby will probably need help with breathing.

Your baby’s rooting reflex – turning to a touch on the cheek – might start around this time. This means they’re developing the reflexes they need for suck-feeding. Your baby might be able to suck on a cotton bud dipped in milk, but they won’t be able to suck a feed yet.

Your baby’s quiet deep sleep (when they don’t move) and light sleep (when they move their limbs and eyes) will increase at about 30 weeks. You’ll also start to see short, alert, eye-opening periods. The length of these periods depends on your baby’s health, the environment and the time of day.

30-33 weeks

Babies born now might not need much medical help, but they’ll need time in hospital to grow and mature.

Your premature baby’s movements will be smoother and more controlled, and they’ll start to hold their arms and legs in a more bent position than younger babies.

Your baby might be very sensitive to touch and handling. It’s good to tell them what you’re about to do so they can start associating your voice with what you’re doing. For example, ‘We’re going to change your nappy now’.

Your baby might start to suck rhythmically and show that they’re ready for suck-feeding. You can get your baby’s senses ready for breastfeeding by letting them smell and taste breastmilk. And you can get your baby ready for the touch sensations of feeding by gently touching your baby’s lips and inside their mouth before feeds.

Your baby’s deep sleep will increase. Their alert periods will come more often, especially if the room is dim. When your baby is alert, they might focus on your face or another interesting object, and they might respond to your voice. Your baby might like eye contact, cuddling or talking during these times – but it’s a good idea to keep it to one thing at a time.

Your baby might shut their eyes tightly if the room is bright.

It’s good to watch your baby’s body language for signs of comfort or stress. If you see your baby putting their hands to their mouth, this means that they’re starting to soothe themselves.

33-36 weeks

Your premature baby is now approaching the date they were due to be born. But even when they’re very close to their due date, they might not be like a term baby.

Your baby will probably respond to sounds and noises in the same way from day to day. You might even know how they’re going to react when you say something to them.

Your baby can move more smoothly and hold their arms and legs in the position they want. They can also move their head from side to side, and their muscles are stronger.

Your baby might still be sensitive to touch and handling. Telling your baby what you’re about to do will help them relax.

Your baby will probably have grown out of apnoea and might not need apnoea medicine.

Your baby will probably be ready to start suck-feeding. They can usually try breastfeeding, which is ideal for premature babies.

Your baby’s sleep and wake states will be clear – quiet sleep, active sleep, drowsy, quiet and alert, awake and fussy, or crying. Their alert states will be quite short but will get longer and happen more often. Your baby can have longer social times, and they can now turn away or close their eyes when they’ve had enough.

Your baby probably won’t cry much. But as your baby gets closer to term, they’ll cry more often to let you know what they want.

37 weeks and beyond

Some premature babies are ready to go home before their expected birth date. Other babies might take longer if they were born very early, had medical complications or needed surgery.

The hospital will have health, growth and development goals for your premature baby to meet before you can take them home. These might include steadily gaining weight, regulating their body temperature outside an incubator, sucking all their feeds, and having no apnoea.

Our article on going home with your premature baby has more information on how to prepare for your baby’s homecoming.