Last updated: November 2013
Premature birth statistics
The World Health Organisation (Preterm birth, Fact sheet N 363, November 2012) has given the following definitions for the different stages of preterm birth.
- extremely preterm: less than 28 weeks
- very preterm: 28 to 32 weeks
- moderate to late preterm 32 to 37 weeks.
Incidence - in England and Wales
- Nearly 7.1 percent (1 in 14) of live births are born preterm .
- 89 percent of singleton babies born extremely preterm are of very low birthweight, whereas fewer than 1 percent of those born at term are.
- 95 percent of preterm births occur after 28 weeks of gestation, but 5 percent occur between 24 and 27 weeks, and just 0.1% occur before 24 weeks.
- In 2011, 5.6 percent of singleton births were preterm whereas 53.1 percent of multiple births were preterm .
Incidence - in Scotland
- 7.1% of all Scottish births were premature in 2012.
- 5.6% of these were singleton births, whereas 57.7% of multiple births were preterm .
Incidence - globally
- 15 million babies are born preterm every year globally, Where reliable data is collected, preterm birth is rising in almost all countries. While over 60% of preterm births occur in Sub-Saharan Africa and South Asia, developed countries such as the USA also have high preterm rates . Across 184 countries, the rate of preterm birth ranges from 5% to 18% of babies born.
A review of published evidence reported the following main causes of preterm birth:
- 30 percent are unexplained and spontaneous
- 30 percent are due to multiple births (twins, triplets, etc.)
- in 20-25 percent the risk factors are genital tract infection, preterm rupture of membranes, antepartum haemorrhage, cervical incompetence and congenital uterine abnormalities
- in 15-20%, elective preterm delivery is due to high maternal blood pressure, fetal growth restriction, congenital abnormalities of the fetus, trauma or medical disorders of pregnancy.
Having more than two preterm births increases the risk of having a preterm birth in a subsequent pregnancy to 70 percent .
In a study of babies born before 27 weeks of gestation in the UK and Ireland in 2006 (the EPICure study), only 7 percent of those born at 22 weeks survived, 42 percent of those born at 24 weeks survived and 78 percent of those born at 26 weeks survived .
When the surviving children born before 27 weeks in the 1995 EPICure study were followed up at age 6 years, a high level of disability was found :
- 22 percent had severe disability (defined as cerebral palsy but not walking, low cognitive scores, blindness, profound hearing loss)
- 24 percent had moderate disability (defined as cerebral palsy but walking, IQ/cognitive scores in the special needs range, a lesser degree of visual or hearing impairment)
- 34 percent had mild disability (defined as low IQ/cognitive score, squint or refractive error, requiring glasses)
- 20 percent had no problems.
When the surviving children born before 26 weeks in the EPICure study were re-assessed in middle childhood (aged 11 years), they found that 45 percent had serious cognitive impairment. The following academic attainment was found :
- They had significantly lower scores for cognitive ability, reading and mathematics
- 13 percent attended special schools.
- 57 percent of those in mainstream schools had special educational needs (SEN).
Those who entered school an academic year early due to preterm birth had similar academic attainment but required more special needs support
 Office for National Statistics, Gestation-specific infant mortality in England and Wales 2011, London ONS, 2013 ( http://www.ons.gov.uk/ons/rel/child-health/gestation-specific-infant-mortality-in-england-and-wales/2011/gest-spec-bulletin-2011.html#tab-Gestational-age)
 Office for National Statistics, Gestation-specific Infant Mortality in England and Wales 2011, London ONS, Office for National Statistics (http://www.ons.gov.uk/ons/rel/child-health/gestation-specific-infant-mortality-in-england-and-wales/2011/gest-spec-bulletin-2011.html#tab-Multiplicity)
 Information Services Division Scotland, Births in Scottish hospitals -Year ending 31st March 2012, Edinburgh NHS National Services Scotland, 2013 (http://www.isdscotland.org/Health-Topics/Maternity-and-Births/Publications/data-tables.asp
 World Health Organisation, Born Too Soon Report. Geneva WHO, 2012 (http://www.who.int/pmnch/media/news/2012/preterm_birth_report/en/index.html)
 Henderson C, Macdonald S, Haye's Midwifery, a textbook for Midwives. Philadelphia Balliere Tindall, 2004
 EPICure (2008), Survival after birth before 27 weeks of gestation, at http://www.epicure.ac.uk/overview/survival
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Premature birth statistics