What is premature birth?

Premature birth is when a baby is born before 37 weeks of pregnancy. If this happens, you and your baby are likely to need specialist support.

What is premature birth? 

Premature birth is when a baby is born before 37 weeks of pregnancy. There are different categories of prematurity:

  • extremely preterm (less than 28 weeks)
  • very preterm (28 to 31 weeks)
  • moderate to late preterm (32 to 37 weeks). 

This may happen spontaneously, which means that a premature labour started on it's own, naturally. Sometimes, a premature birth may need to be planned because it's the safest thing to do for your health or your baby's health. 

How common is premature birth?

About 8 babies out of every 100 in the UK are born before the 37th week of pregnancy. 

What are the symptoms of premature birth?

The following symptoms before 37 weeks of pregnancy could be signs that you are about to go into labour:

  • regular contractions or tightenings
  • pressure in the vaginal area
  • a "show" – when the plug of mucus that has sealed the cervix during pregnancy comes away and out of the vagina
  • a gush or trickle of fluid from your vagina – this could be your waters breaking
  • bleeding from the vagina
  • backache that's not usual for you. 

Read more about the signs of premature labour.

What are the causes of premature birth?

We often don’t know why premature birth happens and it is often difficult for a doctor or midwife to predict if a person will have a premature birth.

But we do know that there are some things that increase the risk of early birth. Sometimes infection can cause premature birth. Rarely, women have a weak cervix.

Women who are having more than one baby also have a higher chance of giving birth prematurely.

If you’ve had a premature baby before, you are more likely to go into early labour again, though the risk of this is still small.

If you’ve had surgery to the neck of your womb (such as removing abnormal cells after a cervical screening), you are also at higher risk.

Lifestyle choices, such as smoking and drinking alcohol can also cause premature labour. Read more about the causes of premature birth.

If you are at risk of premature birth, your doctor or midwife will monitor you closely. Read more about what happens if you are told you are at risk of a premature birth.

Is there treatment for premature birth?

Your treatment may depend on why you are at risk of premature birth and your previous pregnancy history. Being told you are at risk of premature birth can be very worrying, but there are some ways to assess your risk and to try to prevent premature birth.

You may be offered monitoring or treatment to prevent early labour if:

  • you've given birth at less than 34 weeks pregnant before
  • you've had a miscarriage after 14 weeks pregnant before
  • your waters have broken before 37 weeks, in this pregnancy or in previous pregnancies
  • your cervix has been injured in the past, for example through surgery
  • your cervix is shorter than expected (measured with an internal vaginal scan). 

Read more about preventing a premature birth (treatment).

Can I reduce my risk of premature birth?

We don’t always know why preterm labour starts, and often it can’t be prevented. But there are some things you can do to slightly reduce your risk of premature birth.

Do all premature labours start on their own?

Most of the time, premature births happen spontaneously (naturally) and often doctors will not be able to find out why. If you are in early premature labour, your healthcare team may try to slow down labour or delay the birth until later in your pregnancy.

In some cases, pre-term labour or birth is planned because it's safer for the baby to be born sooner rather than later. This could be because of a health condition in the mother (such as pre-eclampsia) or in the baby (such as fetal growth restriction). If you are advised to give birth early, you may be offered an induction or caesarean section.

Some women will be told they are at risk of giving birth early. In these cases, they will have more care or treatment to try and reduce the chances of this happening

What is premature labour like?

Physically, premature labour may be similar to normal labour or it may be faster or less painful, particularly if very premature.

Find out more about giving birth to your premature baby.

A premature birth may be difficult to cope with emotionally. Every parent hopes for a healthy, uncomplicated pregnancy, labour and birth, so it can be very upsetting when this doesn’t happen.

Don’t be afraid to tell your healthcare professional how you feel at any point during your pregnancy or after the birth. They won’t judge you. It is common for a parent’s mental health to be affected in pregnancy or after having a baby, and your healthcare professionals are aware of this. 

You can also talk to a Tommy’s midwife free of charge from 9am–5pm, Monday to Friday on 0800 0147 800 or email them at [email protected]

Find out more about coping with a premature birth

How can premature birth affect my baby?

When a baby is born too soon, they may need special care because they are not quite ready for life outside the womb. 

This means that some premature babies may have some medical problems. The earlier a baby is born, the more vulnerable they are. 

Babies born early may need special care in a neonatal unit, which has specialist facilities for premature babies. Find out more about what happens after your baby is born.

Macdonald, Sue (2017) Mayes’ Midwifery. London, Elsevier Health Sciences UK

NICE (2015). Preterm labour and birth. National Institute for health and care excellence https://www.nice.org.uk/guidance/ng25

NHS Choices. Premature labour and birth. www.nhs.uk/conditions/pregnancy-and-baby/premature-early-labour/ (Page last updated 04/11/2019 Next review due: 04/11/2022)
Clinical Knowledge Summaries. Antenatal care – uncomplicated pregnancy. https://cks.nice.org.uk/antenatal-care-uncomplicated-pregnancy (Page last updated February 2019 Next review due: February 2021)

The Royal College of obstetricians and gynaecologists (2018) Alcohol and pregnancy https://www.rcog.org.uk/en/patients/patient-leaflets/alcohol-and-pregnancy/
World Health Organisation (2018) Preterm birth. https://www.who.int/news-room/fact-sheets/detail/preterm-birth

Review dates
Reviewed: 23 August 2021
Next review: 22 August 2024