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preterm delivery

Delivery before 37 weeks of gestation. Etiology: 1) may be associated with maternal genital tract flora 2) risk factors: a) prior preterm delivery b) periodontal disease [4] c) obesity d) cervical length <= 15 mm high risk, >= 30 mm low risk [10] Laboratory: - positive fetal fibronectin is a risk factor [10] - vaginal fetal fibronectin is a poor predictor of spontaneous preterm birth [15] Special laboratory: - serial transvaginal ultrasound cervical length is a poor predictor or spontaneous preterm birth [15] Complications: 1) low birth weight 2) major cause of perinatal morbidity & mortality in developed nations 3) retinopathy of prematurity [3] 4) cerebral palsy [6] 5) only 12% of infants born < 23 weeks of gestation & 24% of infants born at 25 weeks of gestation had normal school-age neurologic & cognitive assessment [3] 6) all measures of adverse medical & social outcomes,including job-related income, but excluding measures ofcriminality increased with decreasing gestational age [5] 7) increased risk for developing chronic kidney disease in adulthood [19] Management: 1) prophylaxis a) early screening for bacterial vaginosis may be of benefit b) clindamycin 300 mg BID for 5 days in the 2nd trimester may be of benefit for women with abnormal vaginal flora c) 17-alpha-hydroxyprogesterone (Duralutin) 250 mg IM weekly beginning at 15-20 weeks of gestation in high risk women may reduce incidence of preterm delivery [1] d) magnesium sulfate 6 g IV bolus followed by infusion of 1-2 g hourly for 24 hours for women < 34 weeks gestation lowers risk of cerebral palsy [6] - does not result in improved outcomes in children at school age [11] e) vaginal progesterone 200 mg QHS from 22-34 weeks gestation in high-risk women may reduce neonatal death, but does not reduce risk of premature delivery or fetal death [13] f) vaginal progesterone may be best strategy to prevent preterm birth [20] 2) antenatal corticosteroids - for mothers with preterm labor from 22-34 weeks' gestational age [7]; 22-37 weeks' gestation [14] - betamethasone (12 mg, 2 IM injections 24 hours apart) for pregnant women with single fetus 34-36 weeks 5 days of gestation likely to deliver before 37 weeks (preterm labor with intact membranes or spontaneous rupture of membranes) reduces needfor postnatal respiratory support 12% vs 14% for placebo (NNT = 35) [12] - number needed to treat to prevent 1 infant death = 6 at 23-24 weeks gestation & 798 at 34 weeks gestation [16] - antenatal glucocorticoids reduces composite risk of - severe intracranial hemorrhage or death - necrotizing enterocolitis or death - severe retinopathy of prematurity or death [16] - antenatal glucocorticoids at 24-28 weeks gestation is not associated with neurodevelopmental impairment at 2 years of age [17] 3) a cervical pessary implemented in the 2nd trimester can lower risk of preterm delivery in women with a short cervix (RR=0.5) [8,18]

Related

low birth weight infant (preterm infant) premature labor; preterm labor

General

labor & delivery pathologic process

References

  1. Journal Watch 23(10):77, 2003 Lamont RF et al, Obstet Gynecol 101(Mar):516, 2003 Ugwunadu A et al, Lancet 361(Mar 22):983, 2003
  2. Journal Watch 23(14):112, 2003 Meis PJ, Klebanoff M, Thom E, Dombrowski MP, Sibai B, Moawad AH, Spong CY, Hauth JC, Miodovnik M, Varner MW, Leveno KJ, Caritis SN, Iams JD, Wapner RJ, Conway D, O'Sullivan MJ, Carpenter M, Mercer B, Ramin SM, Thorp JM, Peaceman AM, Gabbe S; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Prevention of recurrent preterm delivery by 17 alpha- hydroxyprogesterone caproate. N Engl J Med. 2003 Jun 12;348(24):2379-85. Erratum in: N Engl J Med. 2003 Sep 25;349(13):1299. PMID: 12802023 - Green MF, NEJM 348:2453, 2003
  3. Journal Watch 25(3):21-22, 2005 Marlow N, Wolke D, Bracewell MA, Samara M; EPICure Study Group. Neurologic and developmental disability at six years of age after extremely preterm birth. N Engl J Med. 2005 Jan 6;352(1):9-19. PMID: 15635108
  4. Offenbacher S et al, Progressive periodontal disease and risk of very preterm delivery. Obstet Gynecol 2006; 107:29 PMID: 16394036
  5. Moster D, Lie RT, Markestad T. Long-term medical and social consequences of preterm birth. N Engl J Med. 2008 Jul 17;359(3):262-73. PMID: 18635431
  6. Conde-Agudelo A and Romero R. Antenatal magnesium sulfate for the prevention of cerebral palsy in preterm infants less than 34 weeks' gestation: A systematic review and metaanalysis. Am J Obstet Gynecol 2009 Jun; 200:595. PMID: 19482113
  7. Carlo WA et al Association of Antenatal Corticosteroids With Mortality and Neurodevelopmental Outcomes Among Infants Born at 22 to 25 Weeks' Gestation JAMA. 2011;306(21):2348-2358 PMID: 22147379 http://jama.ama-assn.org/content/306/21/2348.short
  8. Goya M et al Cervical pessary in pregnant women with a short cervix (PECEP): an open-label randomised controlled trial The Lancet, Early Online Publication, 3 April 2012 PMID: 22475493 http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60030-0/fulltext - Caritis SN and Simhan H Cervical pessary use and preterm birth: how little we know The Lancet, Early Online Publication, 3 April 2012 PMID: 22475492 http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60116-0/fulltext
  9. Cnattingius S et al Maternal Obesity and Risk of Preterm Delivery. JAMA. 2013;309(22):2362-2370 PMID: 23757084 http://jama.jamanetwork.com/article.aspx?articleid=1696099
  10. van Baaren GJ et al. Predictive value of cervical length measurement and fibronectin testing in threatened preterm labor. Obstet Gynecol 2014 Jun; 123:1185 PMID: 24807328 http://journals.lww.com/greenjournal/pages/articleviewer.aspx?year=2014&issue=06000&article=00007&type=abstract
  11. Doyle LW et al School-age Outcomes of Very Preterm Infants After Antenatal Treatment With Magnesium Sulfate vs Placebo. JAMA. 2014;312(11):1105-1113 http://jama.jamanetwork.com/article.aspx?articleid=1904828
  12. Gyamfi-Bannerman C, Thom EA, Blackwell SC et al Antenatal Betamethasone for Women at Risk for Late Preterm Delivery. N Engl J Med. Feb 4, 2016 PMID: 26842679 http://www.nejm.org/doi/full/10.1056/NEJMoa1516783
  13. Norman JE, Marlow N, Messow CM et al Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial. Lancet. Feb 23, 2016 PMID: 26921136 Free Article http://thelancet.com/pdfs/journals/lancet/PIIS0140-6736%2816%2900350-0.pdf - Moi BW, Daly M, Dodd JM. Progestogens and preterm birth - not the hoped for panacea? Lancet. Feb 23, 2016 PMID: 26921135 Free full text http://thelancet.com/journals/lancet/article/PIIS0140-6736%2816%2900543-2/fulltext
  14. Saccone G, Berghella V Antenatal corticosteroids for maturity of term or near term fetuses: systematic review and meta-analysis of randomized controlled trials. BMJ 2016;355:i5044 PMID: 27733360 http://www.bmj.com/content/355/bmj.i5044
  15. Esplin MS, Elovitz MA, Iams JD et al Predictive Accuracy of Serial Transvaginal Cervical Lengths and Quantitative Vaginal Fetal Fibronectin Levels for Spontaneous Preterm Birth Among Nulliparous Women. JAMA. 2017;317(10):1047-1056. PMID: 28291893 http://jamanetwork.com/journals/jama/article-abstract/2610337 - Bloom SL,Leveno KJ. Unproven Technologies in Maternal-Fetal Medicine and the High Cost of US Health Care. JAMA. 2017;317(10):1025-1026. PMID: 28291876 http://jamanetwork.com/journals/jama/article-abstract/2610318
  16. Travers CP, Clark RH, Spitzer AR et al. Exposure to any antenatal corticosteroids and outcomes in preterm infants by gestational age: Prospective cohort study. BMJ 2017 Mar 28; 356:j1039 PMID: 28351838 Free Article http://www.bmj.com/content/356/bmj.j1039 - McDonald SD. Antenatal corticosteroids for women at risk of preterm delivery: Timing is critical to maximising benefits for very premature babies. BMJ 2017 Mar 28; 356:j1467 PMID: 28351845 http://www.bmj.com/content/356/bmj.j1467
  17. Baud O, Trousson D, Biran V et al Association Between Early Low-Dose Hydrocortisone Therapy in Extremely Preterm Neonates and Neurodevelopmental Outcomes at 2 Years of Age. JAMA. 2017;317(13):1329-1337 PMID: 28384828 http://jamanetwork.com/journals/jama/article-abstract/2614188 - Marlow N Reevaluating Postnatal Steroids for Extremely Preterm Infants to Prevent Lung Disease. JAMA. 2017;317(13):1317-1318 PMID: 28384808 http://jamanetwork.com/journals/jama/article-abstract/2614166
  18. Saccone G, MD1; Maruotti GM, Giudicepietro A et al Effect of Cervical Pessary on Spontaneous Preterm Birth in Women With Singleton Pregnancies and Short Cervical Length. A Randomized Clinical Trial. JAMA. 2017;318(23):2317-2324 PMID: 29260226 https://jamanetwork.com/journals/jama/article-abstract/2666505 - Silver RM, Branch DW. Cervical Pessary to Prevent Preterm Birth. JAMA. 2017 Dec 19;318(23):2299-2300. PMID: 29260206 https://jamanetwork.com/journals/jama/article-abstract/2666483
  19. Crump C, Sundquist J, Winkleby MA, Sundquist K. Preterm birth and risk of chronic kidney disease from childhood into mid-adulthood: national cohort study. BMJ 2019;365:l1346 PMID: 31043374 https://www.bmj.com/content/365/bmj.l1346
  20. Care A et al. Interventions to prevent spontaneous preterm birth in women with singleton pregnancy who are at high risk: Systematic review and network meta-analysis. BMJ 2022 Feb 15; 376:e064547 PMID: 35168930 PMCID: PMC8845039 Free PMC article https://www.bmj.com/content/376/bmj-2021-064547 - Boelig RC et al. Vaginal progesterone vs intramuscular 17-hydroxyprogesterone caproate for prevention of recurrent preterm birth: A randomized controlled trial. Am J Obstet Gynecol 2022 Feb 18; [e-pub]. PMID: 35189093 https://www.ajog.org/article/S0002-9378(22)00115-6/fulltext