Tommy's PregnancyHub

Gestational age and medical needs

As soon as your premature baby is born, the healthcare team will decide what level of care they need. This will depend on a number of factors.

Your baby's health will often depend on how prematurely they were born. Here is a guide to how different ages of gestation at birth and effect on health.

When you see your premature baby for the first time, it's only natural to feel daunted. They will look smaller, frailer and far more vulnerable than you were expecting and will need special care to overcome this early start in life.

You may also be feeling exhausted, shocked and scared about what the future may hold, so try to stay calm and have faith in the healthcare team who will look after your baby and help you in the first steps of becoming a new parent.

Your baby's health, and the treatment they need, will depend on many factors, including their condition immediately after birth.

How unwell will my premature baby be?

Your baby's care will depend on how many weeks old they are at the time of delivery.

Near-term (34-36 weeks)

At this stage your baby is less likely to have severe breathing problems, but is still at risk of problems with blood sugar levels, blood pressure and infection, and may not be able to breast or bottle-feed quite yet. If that’s the case they are likely to have a small tube passed through the nose into their tummy so that the team can give them milk until they're developed enough to take all the fluid and nutrients they need by mouth. They will need help with feeding through a tube until they have developed the ability to suck and swallow themselves.

Moderate (32-33 weeks)

At this stage your baby will still need specialised care, and may have low blood sugar and mild breathing problems, but their lungs will be much more mature. However, they will still be at risk of hypothermia, low blood pressure and infection.

Very preterm (28-32 weeks)

At this age, your baby will be susceptible to the same conditions as younger babies - but because they are more developed, the risk is lower.

They are still likely to need support with breathing, and are at risk of hypothermia, low blood sugar and infection, but they are less likely to become severely ill. The large majority of babies born at this age in the UK survive to go home. 

Extreme (less than 28 weeks)

At this age, your baby will be transferred to the neonatal intensive care unit after delivery if there isn't one in your hospital.

They will be at high risk of having problems with breathing, as their lungs will not yet be mature enough to breathe independently. They will need breathing support. They will need to be kept very warm to avoid hypothermia, and will need to be given dextrose and IV nutrition to prevent low blood sugar and to help them grow. At the same time they will start to transition on to milk feeds slowly but surely over a period of days. They will be at high risk of low blood pressure and infection. There is a risk of brain injury among babies born at this time so the team will monitor this with ultrasound scans performed at the cotside.

In 1992 the UK changed the definition of preterm live birth (as opposed to miscarriage) from 28 weeks to 24 weeks. This reflects the improved survival rates of babies at 24-28 weeks. In some countries, it is as low as 20 weeks.

Levels of care

Special care baby unit (SCBU) 

Also called the special care baby unit (SCBU, pronounced 'skaboo') or special care unit (SCU), these provide the most simple level of care for babies in their local area. Typically, this might include monitoring of breathing or heart rate, additional oxygen, tube feeding, phototherapy for jaundice. SCBUs also provide emergency services for stabilising babies who are born unexpectedly sick prior to transfer, and stabilise a baby's condition before transferring them to another unit or provide emergency care if necessary. They may also provide some high-dependency services. They receive babies from other units once they are well enough to be cared for there.

Local neonatal unit (LNU)

Local neonatal units (LNUs) provide special care for babies in their local area, except for those who are very unwell and need complex or longer-term intensive care. The majority of babies over 27 weeks of gestation will usually receive their full care, including short periods of intensive care, within their LNU.

Neonatal intensive care units (NICU)

These specialist units have the facilities to care for critically ill premature babies. Babies will be transferred here from around the country to access the specialised expertise that they offer. They provide the whole range of medical neonatal care for their local population, along with additional care for babies and their families referred from the neonatal network.

Transitional care

This level of care is provided when babies are almost ready to go home. Usually mums become the main carers with support from the staff on the neonatal unit.

How your premature baby could look

24-28 weeks

Weight: 1-3.5lb (450-1600g)
Length: 10-13in (25-33cm)

At this stage, your baby will be very thin, with fragile red skin covered with downy hair (lanugo). Their head will look large, they will have soft skull bones, and a small face with a pointed chin and eyelids that may be fused fused shut. They will appear to sleep much of the time

29-34 weeks

Weight: 2-5.5lb (1-2.5kg)
Length: 12-14in (30-35cm)

Your baby will still be quite thin, and their skin will be slightly translucent and still covered in downy hair. In girls you may see tiny nipples. They may move quite vigorously and grasp your finger, and may be able to suck or lick, but they won't be ready to feed by themselves.

35-37 weeks

Weight: 3.5-7lb (1.6-3.4kg)
Length: 15-18in (38-45cm)

By this stage, your baby will be much more robust and will look more like what you'd expect a term baby to look like. They may still be quite thin, with some hair, and they may still need extra help with feeding and breathing and staying warm.

  1. WHO (2012) Preterm birth, Fact sheet N 363, The World Health Organisation, November 2012
  2. NHS and Department of Health (2009) Toolkit for high quality neonatal services
  3. Henderson C, Macdonald S (2012) Mayes Midwifery, A textbook for midwives (14th edition), Balliere Tindall
Review dates

Last reviewed: 5 October, 2016
Next review: 5 October, 2019