Babies born before 37 weeks are considered to have been born prematurely.
Medical language to describe premature babies - who are sometimes referred to as preterm - is based on how long they have been in the womb and how much they weigh.
What is considered a premature baby?
The following definitions are provided by the World Health Organisation.
Length of time in womb (Gestation)
- Term - A baby that has spent at least 37 weeks in the womb
- Preterm - Born before 37 weeks
- Very preterm - Born between 28 and 32 weeks
- Extremely preterm - Born at or before 28 weeks
- Low birthweight - Born weighing less than 2500g (5lbs)
- Very low birthweight - Born weighing less than 1500g (3lbs)
- Extremely low birthweight - Born weighing less than 1000g (2lbs)
Why was my baby born early?
The causes of premature birth are not well understood and for the most part doctors do not know how to prevent it.
Babies can be born prematurely for many different reasons.
- Pregnancies with twins, triplets or more babies are more likely to end early.
- Pre-eclampsia (high blood pressure in the mum) occurs in about ten to 15 per cent of first-time pregnancies, and is responsible for at least 15 per cent of all premature births. It can be dangerous, particularly if it develops rapidly.
- About a third of premature births occur for no apparent reason. Often they happen with little or no warning. It may be that an infection involving the sack around the baby in the womb can trigger the delivery.
- Stressful events can start labour early. However there is no evidence that the normal stresses of day-to-day living can bring on premature birth.
What happens if I go into labour early?
In some cases, the waters break early starting labour.
If this happens when a baby has been in the womb for less than 35 weeks, doctors usually give the mum two sets of drugs. One is to delay the labour for a day or two, while the other is to help the baby's lungs to mature quickly so that they will function better.
When do doctors advise early delivery of a baby?
In a few cases, an antenatal screening test might show that a baby is not growing well in the womb, often because there is not enough blood flowing to and from the placenta.
If doctors believe the baby is going to be safer outside the womb, they would advise early delivery. In this case a caesarean section may be recommended as it puts less stress on the baby.
What support is available to me if my baby is born premature?
We understand how distressing it can be when your baby is born premature or sick.