Premature birth statistics

A preterm birth is one that happens before 37 weeks of pregnancy. Globally, more than 1 in 10 pregnancies will experience in preterm birth.

A preterm birth is one that happens before 37 completed weeks of pregnancy.

The World Health Organisation gives the following definitions for the different stages of preterm birth:

  • Extremely preterm: before 28 weeks
  • Very preterm: from 28 to 31 weeks
  • Moderate to late preterm: from 32 to <37 weeks.

General UK premature birth statistics

  • Across the UK, there were around 53,000 babies born prematurely in 2021. 
  • In England and Wales in 2021, 7.6% of births were preterm.
  • This is an increase from 7.4% in 2020, ending three consecutive years on a decrease in the percentage of preterm live births. 
  • In England and Wales, the percentage of preterm live births varies significantly depending on the ethnicity of the baby, with babies in the Black ethnic group having the highest proportion of preterm births at 8.7% in 2021. 

Of the births that were preterm in the England and Wales in 2021:

  • 6% were extremely preterm (before 28 weeks)
  • 10% were very preterm (between 28 and 32 weeks)
  • 83% were moderately preterm (between 32 and <37 weeks).

In 2019, live births where gestational age was under 24 weeks increased to 0.15% compared with 0.13% in 2018 and 0.11% in 2010.

Chances of survival following preterm birth

Medical advances mean that we are getting better at treating preterm babies but the chances of survival still depend on gestational age (week of pregnancy) at time of birth.

  • Less than 22 weeks is close to zero chance of survival
  • 22 weeks is around 10%
  • 24 weeks is around 60%
  • 27 weeks is around 89%
  • 31 weeks is around 95%
  • 34 weeks is equivalent to a baby born at full term.

Preterm birth and neonatal death

Complications arising from premature birth is the leading cause of neonatal death (death in the first few weeks after birth) in the UK. 

Preterm birth and multiple pregnancies

Having more than one baby is a risk factor for preterm birth. On average, most singleton pregnancies last 39 weeks, twin pregnancies 37 weeks and triplets 33 weeks.

  • Risk of prematurity with singleton pregnancy: 7%
  • Risk of prematurity with multiple pregnancy: 57%

Risk of disability in preterm children

Generally, the earlier the birth, the higher the risk of problems. However these are only statistics and cannot predict how an individual child will do; some extremely premature babies do very well and develop into healthy children.

  • 1 in 10 of all premature babies will have a permanent disability such as lung disease, cerebral palsy, blindness or deafness.
  • 1 in 2 of premature babies born before 26 weeks of gestation will have some sort of disability (this includes mild disability such as requiring glasses).

In one study of 241 children born before 26 weeks' gestation the following was found:

  • 22% severe disability (eg cerebral palsy + not walking, low cognitive scores, blindness, profound deafness)
  • 24% moderate disability (eg cerebral palsy + walking, IQ/cognitive scores in the special needs range, lesser degree of visual or hearing impairment)
  • 34% mild disability (defined as low IQ/cognitive score, squint, requiring glasses)
  • 20% no problems.

Preterm birth by ethnicity

The latest statistics from the Office for National Statistics show the percentage of preterm births by ethnicity in England and Wales.

Since 2021. babies from Black ethnic group have had the highest proportion of preterm births since data collection began in 2007. 

Between 2020 and 2021, the biggest percentage increase in preterm live births was in the Asian ethnic group, from 7.5% to 8.1%.

These statistics show the percentage of preterm births by ethnicity in 2021:

  • Black: 8.7%
  • Asian: 8.1%%
  • White: 7.4%
  • Mixed or Multiple:7%
  • Any Other ethnic group: 7%


Causes of preterm birth

In some cases a cause of preterm birth can be shown but more often it is unknown or unclear.

In 1 in 4 preterm births, the birth is planned (induced labour or c-section) to save the life of mother or baby from pregnancy complications such as pre-eclampsia, fetal growth restriction, waters breaking early (PPROM) or infection

Preventing premature birth

Too often health professionals are not able to tell women why they have had a premature birth. This area of research is underfunded, with many taking an unhelpful (and unique to pregnancy) approach of ‘It was not meant to be’.

Research into why premature birth happens is the only way we can save lives and prevent future loss. Tommy's funds more than £400k of research into premature birth every year. We are focused on predicting early which women will have a premature birth and treating them to prevent it happening.

Read about our research into prematurity here.

Join us for change

Together we can make a difference. We need everyone's help to change the statistics and find out why miscarriages happen. You can sign up today to support Tommy's work.  

Media requests about premature birth

Our clinicians, scientists and researchers are available to speak about preterm birth for press and media. If you are interested in speaking to a clinician, please contact Tommy's press office on 0207 398 3436 or email [email protected].

ONS. (2022) Births in England and Wales 2021 [Online]. Available on: (Accessed: 09/03/23) 

ONS (2022) Birth characteristics in England and Wales 2021 [Online]. Available on: (Accessed: 09/03/23) 

WHO (2018) Preterm birth Factsheet. World Health Organisation.  

NICE (2022) Preterm labour and birth NICE guideline [NG25]. National Institute of Health and Care Excellence. 

WHO (2012) Born too soon. The global action report on preterm birth. 

ONS (2013) Pregnancy and ethnic factors influencing births and infant mortality. Office of National Statistics.

Wood NS, Marlow N et al (2000) N Engl J Med. Neurologic and developmental disability after extremely preterm birth. EPICure Study Group. 2000 Aug 10;343(6):378-84. 

Marlow N1, Wolke D et al (2005) Neurologic and developmental disability at six years of age after extremely preterm birth. N Engl J Med. 2005 Jan 6;352(1):9-19.