According to World Health Organization (WHO) estimates, prematurity is the leading underlying cause of death in children under five years, with over one million babies dying each year worldwide due to complications of preterm birth. For those who survive, the consequences of being born too soon can continue throughout the life course, impacting individuals, families and communities.
- Extremely preterm (<28 weeks)
- Very preterm (28 to <32 weeks)
- Moderate to late preterm (32 to <37 weeks)
The rates of prematurity are rising around the world. Of the 15 million babies born preterm every year, 60% occur in Africa and South Asia. A baby’s risk of death due to prematurity depends largely on where he or she is born: In high-income countries, 50% of babies born at less than 28 weeks survive, while half of babies born at 32 weeks die in low-income countries. Moderate or late preterm babies can often be cared for effectively with simple, low-cost, evidence-based methods requiring limited technology, such as kangaroo mother care and feeding support.
Although the causes of preterm birth are complex, risk factors include maternal smoking and substance abuse, adolescent pregnancy, infections like syphilis, Group B streptococcus and malaria, pre-eclampsia, bleeding in pregnancy and premature rupture of membranes. High quality preconception and prenatal care are key factors in preventing preterm delivery. Furthermore, social determinants can greatly influence the likelihood that a woman will delivery prematurely. Disparities in preterm birth by factors such as socioeconomic status and race persist. For example, in the United States, the risk of premature delivery is three times greater among black women compared to white women.
There are a number of challenges related to the management, prevention and treatment of preterm births, particularly with pregnancy dating. Last menstrual period is often unknown or unreliable, and until recently, there were no international standards for relating ultrasound measurement of fetal crown-rump length to gestational age. Even with these new standards in place, access to ultrasound and trained sonographers in low-resource settings can be highly variable. Preventative strategies and early treatment can help mitigate the effects of preterm birth, but these practices require continued research. For example, while administering antenatal corticosteroids has been promoted as an effective way to prepare preterm babies’ immature lungs for life outside the womb in case of imminent preterm birth, the treatment is debated for its implementation challenges, including insufficient support for managing side effects. Additionally, early neurological development care for preterm newborns is an emerging field, but further evidence is needed to evaluate the efficacy of those interventions.
At the policy level, the global issue of preterm birth has gained momentum in recent years, especially through the Every Newborn Action Plan. New estimations suggest that scaling up evidence-based, low-cost interventions to prevent and manage prematurity could avert 70% of preterm deaths in low- and middle-income countries. However, scaling interventions for the mother-baby dyad in a way that provides equity in access and quality of care remains a crucial challenge.
- WHO Recommendations on Interventions to Improve Preterm Birth Outcomes | World Health Organization
- Born Too Soon | Reproductive Health (Series)
- International Standards for Early Fetal Size and Pregnancy Dating Based on Ultrasound Measurement of Crown–Rump Length in the First Trimester of Pregnancy | INTERGROWTH-21st Project
- Helping Babies Survive | American Academy of Pediatrics
- Country Profiles for Preterm and Low Birth Weight Prevention and Care | Every Preemie-SCALE
- Guideline for Family Centred Developmental Care | The Northern Neonatal Network
- Cervical Cerclage Guideline | Royal College of Obstetricians & Gynecologists
- Prenatal Administration of Progesterone for Preventing Preterm Birth in Women Considered to be at Risk of Preterm Birth | Cochrane Database of Systematic Reviews
- Born too soon: The global action report on preterm birth
The Partnership for Maternal, Newborn & Child Health | May 2012
- Mortality risk in preterm and small-for-gestational-age infants in low-income and middle-income countries: A pooled country analysis
The Lancet | August 2013
- Prevention of preterm delivery: Current challenges and future prospects
International Journal of Women’s Health | October 2016
- Preventing preterm births: Analysis of trends and potential reductions with interventions in 39 countries with very high human development index
The Lancet | January 2013
- The worldwide incidence of preterm birth: A systematic review of maternal mortality and morbidity
Bulletin of the World Health Organization | January 2010
- Maternal morbidity and preterm birth in 22 low- and middle-income countries: A secondary analysis of the WHO Global Survey dataset
BMC Pregnancy and Childbirth | January 2014
- National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: A systematic analysis and implications
The Lancet | June 2012
- Global report on preterm birth & stillbirth: The foundation for innovative solutions and improved outcomes
BMC Pregnancy and Childbirth | February 2010
- Epidemiology and causes of preterm birth
The Lancet | April 2008
Documents & Reports
- 15 million preterm births: What is the potential with better quality of care? (Part 1)
- 15 million preterm births: What is the potential with better quality of care? (Part 2)
- Understanding fetal growth across populations towards a phenotypic classification of preterm birth and intrauterine growth retardation