Preterm birth

Preterm birth
Other namesPremature birth, preemies, premmies
Intubated preterm baby in an incubator
SpecialtyNeonatology, Pediatrics, Obstetrics
SymptomsBirth of a baby at younger than 37 weeks' gestational age[1]
ComplicationsCerebral palsy, delays in development, hearing problems, sight problems[1]
CausesOften unknown[2]
Risk factorsDiabetes, high blood pressure, Multiple gestation, obesity or underweight, a number of vaginal infections, celiac disease, tobacco smoking, psychological stress[2][3][4]
PreventionProgesterone[5]
TreatmentCorticosteroids, keeping the baby warm through skin-to-skin contact, supporting breastfeeding, treating infections, supporting breathing[2][6]
Frequency~15 million a year (12% of deliveries)[2]
Deaths805,800[7]

Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks.[1] Extreme preterm[2] is less than 28 weeks, very early preterm birth is between 28 and 32 weeks, early preterm birth occurs between 32 and 34 weeks, late preterm birth is between 34 and 36 weeks' gestation.[8] These babies are also known as premature babies or colloquially preemies (American English)[9] or premmies (Australian English).[10] Symptoms of preterm labor include uterine contractions which occur more often than every ten minutes and/or the leaking of fluid from the vagina before 37 weeks.[11][12] Premature infants are at greater risk for cerebral palsy, delays in development, hearing problems and problems with their vision.[1] The earlier a baby is born, the greater these risks will be.[1]

The cause of spontaneous preterm birth is often not known.[2] Risk factors include diabetes, high blood pressure, multiple gestation (being pregnant with more than one baby), being either obese or underweight, vaginal infections, air pollution exposure, tobacco smoking, and psychological stress.[2][3][13] For a healthy pregnancy, medical induction of labor or cesarean section are not recommended before 39 weeks unless required for other medical reasons.[2] There may be certain medical reasons for early delivery such as preeclampsia.[14]

Preterm birth may be prevented in those at risk if the hormone progesterone is taken during pregnancy.[5] Evidence does not support the usefulness of bed rest.[5][15] It is estimated that at least 75% of preterm infants would survive with appropriate treatment, and the survival rate is highest among the infants born the latest in gestation.[2] In women who might deliver between 24 and 37 weeks, corticosteroid treatment may improve outcomes.[6][16] A number of medications, including nifedipine, may delay delivery so that a mother can be moved to where more medical care is available and the corticosteroids have a greater chance to work.[17] Once the baby is born, care includes keeping the baby warm through skin-to-skin contact or incubation, supporting breastfeeding and/or formula feeding, treating infections, and supporting breathing.[2] Preterm babies sometimes require intubation.[2]

Preterm birth is the most common cause of death among infants worldwide.[1] About 15 million babies are preterm each year (5% to 18% of all deliveries).[2] Late preterm birth accounts for 75% of all preterm births.[18] This rate is inconsistent across countries. In the United Kingdom 7.9% of babies are born pre-term and in the United States 12.3% of all births are before 37 weeks gestation.[19][20] Approximately 0.5% of births are extremely early periviable births (20–25 weeks of gestation), and these account for most of the deaths.[21] In many countries, rates of premature births have increased between the 1990s and 2010s.[2] Complications from preterm births resulted globally in 0.81 million deaths in 2015, down from 1.57 million in 1990.[7][22] The chance of survival at 22 weeks is about 6%, while at 23 weeks it is 26%, 24 weeks 55% and 25 weeks about 72%.[23][needs update] The chances of survival without any long-term difficulties are lower.[24]

  1. ^ a b c d e f "Preterm Labor and Birth: Condition Information". National Institutes of Health. 3 November 2014. Archived from the original on 2 April 2015. Retrieved 7 March 2015.
  2. ^ a b c d e f g h i j k l m World Health Organization (November 2014). "Preterm birth Fact sheet N°363". who.int. Archived from the original on 7 March 2015. Retrieved 6 March 2015.
  3. ^ a b "What are the risk factors for preterm labor and birth?". National Institutes of Health. 3 November 2014. Archived from the original on 5 April 2015. Retrieved 7 March 2015.
  4. ^ Cite error: The named reference SacconeBerghella2015 was invoked but never defined (see the help page).
  5. ^ a b c "What treatments are used to prevent preterm labor and birth?". National Institutes of Health. 3 November 2014. Archived from the original on 2 April 2015. Retrieved 7 March 2015.
  6. ^ a b "What treatments can reduce the chances of preterm labor & birth?". National Institutes of Health. 11 June 2013. Archived from the original on 2 April 2015. Retrieved 7 March 2015.
  7. ^ a b Wang H, Naghavi M, Allen C, Barber RM, Bhutta ZA, Carter A, et al. (BD 2015 Mortality and Causes of Death Collaborators) (October 2016). "Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1459–1544. doi:10.1016/s0140-6736(16)31012-1. PMC 5388903. PMID 27733281.
  8. ^ Brown HK, Speechley KN, Macnab J, Natale R, Campbell MK (June 2014). "Neonatal morbidity associated with late preterm and early term birth: the roles of gestational age and biological determinants of preterm birth". International Journal of Epidemiology. 43 (3): 802–814. doi:10.1093/ije/dyt251. PMC 4052131. PMID 24374829.
  9. ^ "preemie noun – Definition, pictures, pronunciation and usage notes | Oxford Advanced Learner's Dictionary at". Oxfordlearnersdictionaries.com. Retrieved 6 May 2022.
  10. ^ "Premmie".
  11. ^ "What are the symptoms of preterm labor?". National Institutes of Health. 11 June 2013. Archived from the original on 2 April 2015. Retrieved 7 March 2015.
  12. ^ Vink J, Myers K (October 2018). "Cervical alterations in pregnancy". Best Practice & Research. Clinical Obstetrics & Gynaecology. Biological Basis and Prevention of Preterm Birth Treatment. 52: 88–102. doi:10.1016/j.bpobgyn.2018.03.007. PMC 6282836. PMID 30314740.
  13. ^ Korten I, Ramsey K, Latzin P (January 2017). "Air pollution during pregnancy and lung development in the child". Paediatric Respiratory Reviews. 21: 38–46. doi:10.1016/j.prrv.2016.08.008. PMID 27665510.
  14. ^ "What causes preterm labor and birth?". National Institutes of Health. 3 November 2014. Archived from the original on 2 April 2015. Retrieved 7 March 2015.
  15. ^ Sosa CG, Althabe F, Belizán JM, Bergel E (March 2015). "Bed rest in singleton pregnancies for preventing preterm birth". The Cochrane Database of Systematic Reviews. 2015 (3): CD003581. doi:10.1002/14651858.CD003581.pub3. PMC 7144825. PMID 25821121.
  16. ^ "Antenatal Corticosteroid Therapy for Fetal Maturation". ACOG. October 2016. Archived from the original on 29 September 2016. Retrieved 27 September 2016.
  17. ^ Haram K, Mortensen JH, Morrison JC (March 2015). "Tocolysis for acute preterm labor: does anything work". The Journal of Maternal-Fetal & Neonatal Medicine. 28 (4): 371–378. doi:10.3109/14767058.2014.918095. PMID 24990666. S2CID 20078137.
  18. ^ Trilla CC, Medina MC, Ginovart G, Betancourt J, Armengol JA, Calaf J (August 2014). "Maternal risk factors and obstetric complications in late preterm prematurity". European Journal of Obstetrics, Gynecology, and Reproductive Biology. 179: 105–109. doi:10.1016/j.ejogrb.2014.05.030. PMID 24965989.
  19. ^ Chow YH, Dattani N (26 February 2009). "Estimating conception statistics using gestational age information from NHS Numbers for Babies data". Health Statistics Quarterly. 41 (41): 21–27. doi:10.1057/hsq.2009.5. PMID 19320250. S2CID 23996035.
  20. ^ Mathews TJ, Miniño AM, Osterman MJ, Strobino DM, Guyer B (January 2011). "Annual summary of vital statistics: 2008". Pediatrics. 127 (1): 146–157. doi:10.1542/peds.2010-3175. PMC 4079290. PMID 21173001.
  21. ^ Ecker JL, Kaimal A, Mercer BM, Blackwell SC, deRegnier RA, Farrell RM, et al. (American College of Obstetricians and Gynecologists; Society for Maternal-Fetal Medicine) (October 2017). "Obstetric Care consensus No. 6: Periviable Birth". Obstetrics and Gynecology. 130 (4): e187–e199. doi:10.1097/AOG.0000000000002352. PMID 28937572.
  22. ^ Naghavi M, Wang H, Lozano R, Davis A, Liang X, Zhou M, et al. (GBD 2013 Mortality and Causes of Death Collaborators) (January 2015). "Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013". Lancet. 385 (9963): 117–171. doi:10.1016/S0140-6736(14)61682-2. PMC 4340604. PMID 25530442.
  23. ^ Cloherty and Stark's Manual of Neonatal Care (9th ed.). Lippincott Williams & Wilkins. 2022. p. 162. ISBN 9781975159559.
  24. ^ Jarjour IT (February 2015). "Neurodevelopmental outcome after extreme prematurity: a review of the literature". Pediatric Neurology. 52 (2): 143–152. doi:10.1016/j.pediatrneurol.2014.10.027. PMID 25497122.