Premature baby development: the basics

A premature baby’s development typically happens in the same order as it would have happened in the womb.

But premature babies might have some health challenges along the way. Sometimes premature babies also have delays in growth and development. Very premature babies and premature babies with medical challenges are more likely to have delays.

For example, a premature baby born at 32 weeks is likely to act differently from a baby born at 26 weeks, who has had many medical challenges by the time they get to 32 weeks. The baby born at 26 weeks might take extra time to put on weight, learn to feed and come out into the social world.

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

26 weeks

At 26 weeks, a baby in the womb is about 35 cm long and weighs about 760 gm. But premature babies are often small for their age. A baby born at 26 weeks would probably fit snugly into your hand.

At this age your premature baby’s main job is to grow, sleep and become medically stable.

Your baby might open their eyes occasionally, but they can’t focus. Light or other visual stimuli might stress their body’s systems. Your baby’s nurse might place a cover over your baby’s incubator, and some neonatal intensive care units (NICUs) dim the lights at night.

Your baby’s movements are often jerks, twitches or startles. Your baby doesn’t yet have good muscle tone and can’t curl up. Hospital staff will put your baby in a curled-up position, support their body with bedding and keep them warm. This helps your baby keep up their energy.

Your baby might also have apnoea. This is common for very premature babies. The breath triggering part of your baby’s brain hasn’t fully developed yet, so pauses between breaths are common. Your baby will grow out of it.

Your baby’s ears and hearing structures are already fully formed, but your baby might be sensitive to external sounds. Your baby might notice your voice but they can’t respond to you yet.

Your baby won’t be able to feed from your breast yet.

Your baby’s skin is fragile and sensitive, and they might get stressed if they’re handled or touched. The nurses will probably encourage you to ‘comfort hold’ your baby but not stroke them.

Our article on touching, holding and massaging your 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, babies in the womb continue to put on weight and grow longer. But if your premature baby is sick, their weight gain might not keep up with a baby in the womb. Also, hospitals use careful, staged feeding plans to protect your baby’s immature gut from infection, and this might slow weight gain.

At this age, babies start blinking. They also grow eyelashes and eyebrows.

Your baby still has low muscle tone and is likely to have twitches and tremors.

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

Your baby might open their eyes, but they probably still can’t focus or get their eyes moving together.

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 start to give you some clues to what they like and dislike.

Your baby might begin sucking, but they still can’t feed from your breast. To breastfeed, they need to know how to suck, swallow and breathe in the right order.

Your baby’s skin is still fragile and sensitive. But if your baby is medically stable, you might be able to start skin-to-skin contact by doing kangaroo care.

28-30 weeks

In the womb a baby keeps getting heavier and longer, starts to move more often, knows the difference between some sounds – for example, voices and music – starts to grasp with their hands, and opens and shuts their eyes.

At this age, your premature baby will still be well supported with bedding and positioning, but they might move and stretch more actively as their muscle tone gets better.

Your baby’s quiet deep sleep (when they don’t move) and light sleep (when they move their limbs and eyes) increase at about 30 weeks. You’ll also start to see short alert, eye-opening periods, but this can be affected by your baby’s health, the environment or the time of day.

Your baby is starting to close their eyelids tightly if it’s bright, but they still can’t move their eyes together very much. Their eyes wouldn’t usually get much stimulation at this age, so it might help to limit what they see.

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

Your baby’s rooting reflex – turning to a touch on the cheek – might start around this time. This means they’re getting ready for breastfeeding. Your baby might even start sucking, but they can’t feed at your breast yet.

Your baby might still be sensitive to touch, but they like steady, gentle, hands-on touch or skin-to-skin contact. You might be able to get involved in caring for your baby about now.

30-33 weeks

At this age, a baby’s organs are maturing. A baby born now might not need much medical help.

Your premature baby’s movement is smoother and more controlled, and they’ll start to bend their arms and legs for themselves.

Your baby’s deep sleep increases. Their alert periods come more often, especially if the room is dim. When they’re alert, your baby might focus on your face or another interesting object, and they might show an obvious response to your voice. Your baby might shut their eyes tightly if the room is bright.

Your baby might like eye contact, cuddling or talking during these times – but it’s still a good idea to keep it to one thing at a time. And you can also watch your baby’s body language for signs of stress.

Your baby might start to suck rhythmically and might show that they’re ready to suck to feed. Letting your baby smell and taste breastmilk gets their senses ready for breastfeeding. Gently rubbing around your baby’s lips and inside their mouth before feeds helps your baby get ready for the touch sensations of feeding from your breast.

If you see your baby putting their hands to their mouth, this means that they’re starting to soothe themselves.

Your baby might still be very sensitive to touch and handling. It’s helpful 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’.

33-36 weeks

Your baby is now approaching the date they were due to be born. But even when they’ve reached 37 weeks, they aren’t necessarily like a full-term baby.

Your baby can now move more smoothly and bend their arms and legs. They can also move their head from side to side, and their muscle tone is stronger.

Your baby will be much less likely to experience apnoea.

Your baby’s states are clear – quiet sleep, active sleep, drowsy, quiet and alert, awake and fussy, or crying. Their alert states are still quite short, but they’re getting longer and happening 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 is more likely to 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 probably still doesn’t cry much. But as your baby gets closer to term, they’ll cry more often to let you know what they want.

Your baby can usually start breastfeeding around this time.

Your baby might still be sensitive to touch and handling, although telling your baby what you’re about to do will help them relax over time.

37 weeks and beyond

Your baby might be ready to go home before their expected birth date. But it might take longer if your baby has had surgery or an illness.

The hospital will have health, growth and development goals for your baby to meet before you can take them home. These might include steadily gaining weight, feeding from your breast or a bottle at all feeds, and having no problems with apnoea.

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