Outcomes of Admissions for Preterm Labor
17 March 2017
11 May 2017
22 June 2017 (online)
Objective This study aims to quantitate the incidence of preterm labor (PTL) admissions and determine the frequency and predictors of preterm delivery (PTD) during these admissions.
Study Design Retrospective cohort of singleton pregnancies within Kaiser Permanente Northern California, 2001 to 2011. PTL admissions were defined as inpatient encounters > 24 hours with an International Classification of Diseases, 9th Revision code for PTL.
Results Total study population was 365,897 with PTL admission rate 11%. PTD occurred in 85% of pregnancies with PTL admission. Delivery occurred within 48 hours of admission in 96% ≥34 weeks, 67% 31 to 33 weeks, and 51.9% <31 weeks. Predictors of delivery during PTL admission included gestational age 34 to 36 weeks (adjusted odds ratio [aOR], 6.90), chorioamnionitis (aOR, 105.58), and preterm rupture of membranes (aOR 19.29).
Conclusion We demonstrate a high rate of PTD per PTL admission in a highly integrated health care system. More work is needed to determine optimal practices for hospitalization and treatment of women diagnosed with PTL.
1. M.K. discloses grants from GlaxoSmithKline during the conduct of this study.
2. L.B. reports personal fees from GlaxoSmithKline during the conduct of this study and outside the submitted work.
3. E.W., S.L., and M.G. report grants from GlaxoSmithKline during the conduct of this study.
- 1 Johnson S, Evans TA, Draper ES. , et al. Neurodevelopmental outcomes following late and moderate prematurity: a population-based cohort study. Arch Dis Child Fetal Neonatal Ed 2015; 100 (04) F301-F308
- 2 Moore T, Hennessy EM, Myles J. , et al. Neurological and developmental outcome in extremely preterm children born in England in 1995 and 2006: the EPICure studies. BMJ 2012; 345: e7961
- 3 Callaghan WM, MacDorman MF, Rasmussen SA, Qin C, Lackritz EM. The contribution of preterm birth to infant mortality rates in the United States. Pediatrics 2006; 118 (04) 1566-1573
- 4 Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet 2008; 371 (9606): 75-84
- 5 Tucker JM, Goldenberg RL, Davis RO, Copper RL, Winkler CL, Hauth JC. Etiologies of preterm birth in an indigent population: is prevention a logical expectation?. Obstet Gynecol 1991; 77 (03) 343-347
- 6 Henderson JJ, McWilliam OA, Newnham JP, Pennell CE. Preterm birth aetiology 2004-2008. Maternal factors associated with three phenotypes: spontaneous preterm labour, preterm pre-labour rupture of membranes and medically indicated preterm birth. J Matern Fetal Neonatal Med 2012; 25 (06) 642-647
- 7 Moutquin JM. Classification and heterogeneity of preterm birth. BJOG 2003; 110 (Suppl. 20) 30-33
- 8 Romero R, Espinoza J, Kusanovic JP. , et al. The preterm parturition syndrome. BJOG 2006; 113 (Suppl. 03) 17-42
- 9 Gotsch F, Gotsch F, Romero R. , et al. The preterm parturition syndrome and its implications for understanding the biology, risk assessment, diagnosis, treatment and prevention of preterm birth. J Matern Fetal Neonatal Med 2009; 22 (02) (Suppl. 02) 5-23
- 10 Di Renzo GC, Roura LC. ; European Association of Perinatal Medicine-Study Group on Preterm Birth. Guidelines for the management of spontaneous preterm labor. J Perinat Med 2006; 34 (05) 359-366
- 11 Berkman ND, Thorp Jr JM, Lohr KN. , et al. Tocolytic treatment for the management of preterm labor: a review of the evidence. Am J Obstet Gynecol 2003; 188 (06) 1648-1659
- 12 Duckitt K, Thornton S, O'Donovan OP, Dowswell T. Nitric oxide donors for treating preterm labour. Cochrane Database Syst Rev 2014; 5 (05) CD002860
- 13 Flenady V, Reinebrant HE, Liley HG, Tambimuttu EG, Papatsonis DN. Oxytocin receptor antagonists for inhibiting preterm labour. Cochrane Database Syst Rev 2014; 6 (06) CD004452
- 14 Han S, Crowther CA, Moore V. Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour. Cochrane Database Syst Rev 2010; (07) CD000940
- 15 King J, Flenady V, Cole S, Thornton S. Cyclo-oxygenase (COX) inhibitors for treating preterm labour. Cochrane Database Syst Rev 2005; (02) CD001992
- 16 Lamont RF. The development and introduction of anti-oxytocic tocolytics. BJOG 2003; 110 (Suppl. 20) 108-112
- 17 Neilson JP, West HM, Dowswell T. Betamimetics for inhibiting preterm labour. Cochrane Database Syst Rev 2014; 2 (02) CD004352
- 18 Hösli I, Sperschneider C, Drack G, Zimmermann R, Surbek D, Irion O. ; Swiss Society of Obstetrics and Gynecology. Tocolysis for preterm labor: expert opinion. Arch Gynecol Obstet 2014; 289 (04) 903-909
- 19 van Vliet EO, Boormans EM, de Lange TS, Mol BW, Oudijk MA. Preterm labor: current pharmacotherapy options for tocolysis. Expert Opin Pharmacother 2014; 15 (06) 787-797
- 20 Badgery-Parker T, Ford JB, Jenkins MG, Morris JM, Roberts CL. Patterns and outcomes of preterm hospital admissions during pregnancy in NSW, 2001-2008. Med J Aust 2012; 196 (04) 261-265
- 21 Fuchs IB, Henrich W, Osthues K, Dudenhausen JW. Sonographic cervical length in singleton pregnancies with intact membranes presenting with threatened preterm labor. Ultrasound Obstet Gynecol 2004; 24 (05) 554-557
- 22 Adams MM, Harlass FE, Sarno AP, Read JA, Rawlings JS. Antenatal hospitalization among enlisted servicewomen, 1987-1990. Obstet Gynecol 1994; 84 (01) 35-39
- 23 Bacak SJ, Callaghan WM, Dietz PM, Crouse C. Pregnancy-associated hospitalizations in the United States, 1999-2000. Am J Obstet Gynecol 2005; 192 (02) 592-597
- 24 Scott CL, Chavez GF, Atrash HK, Taylor DJ, Shah RS, Rowley D. Hospitalizations for severe complications of pregnancy, 1987-1992. Obstet Gynecol 1997; 90 (02) 225-229
- 25 Gazmararian JA, Petersen R, Jamieson DJ. , et al. Hospitalizations during pregnancy among managed care enrollees. Obstet Gynecol 2002; 100 (01) 94-100
- 26 Adelson PL, Child AG, Giles WB, Henderson-Smart DJ. Antenatal hospitalisations in New South Wales, 1995-96. Med J Aust 1999; 170 (05) 211-215
- 27 Liu S, Heaman M, Sauve R. , et al; Maternal Health Study Group of the Canadian Perinatal Surveillance System. An analysis of antenatal hospitalization in Canada, 1991-2003. Matern Child Health J 2007; 11 (02) 181-187
- 28 Escobar GJ, Fischer A, Kremers R, Usatin MS, Macedo AM, Gardner MN. Rapid retrieval of neonatal outcomes data: the Kaiser Permanente Neonatal Minimum Data Set. Qual Manag Health Care 1997; 5 (04) 19-33
- 29 Chimmula S, Dhuru R, Folck B. , et al. PS2–44: VDW data sources: Kaiser Permanente Northern California. Clin Med Res 2012; 10 (03) 193
- 30 Fenton TR. A new growth chart for preterm babies: Babson and Benda's chart updated with recent data and a new format. BMC Pediatr 2003; 3: 13
- 31 Liggins GC, Howie RN. A controlled trial of antepartum glucocorticoid treatment for prevention of the respiratory distress syndrome in premature infants. Pediatrics 1972; 50 (04) 515-525
- 32 NIH Consensus Development Panel on the Effect of Corticosteroids for Fetal Maturation on Perinatal Outcomes. Effect of corticosteroids for fetal maturation on perinatal outcomes. JAMA 1995; 273 (05) 413-418
- 33 Crowley P, Chalmers I, Keirse MJ. The effects of corticosteroid administration before preterm delivery: an overview of the evidence from controlled trials. Br J Obstet Gynaecol 1990; 97 (01) 11-25
- 34 Tyson JE, Parikh NA, Langer J, Green C, Higgins RD. ; National Institute of Child Health and Human Development Neonatal Research Network. Intensive care for extreme prematurity--moving beyond gestational age. N Engl J Med 2008; 358 (16) 1672-1681
- 35 McPheeters ML, Miller WC, Hartmann KE. , et al. The epidemiology of threatened preterm labor: a prospective cohort study. Am J Obstet Gynecol 2005; 192 (04) 1325-1329 , discussion 1329–1330
- 36 American College of Obstetricians and Gynecologists; Committee on Practice Bulletins—Obstetrics. ACOG practice bulletin no. 127: Management of preterm labor. Obstet Gynecol 2012; 119 (06) 1308-1317
- 37 Escobar GJ, Clark RH, Greene JD. Short-term outcomes of infants born at 35 and 36 weeks gestation: we need to ask more questions. Semin Perinatol 2006; 30 (01) 28-33
- 38 Kuzniewicz MW, Parker SJ, Schnake-Mahl A, Escobar GJ. Hospital readmissions and emergency department visits in moderate preterm, late preterm, and early term infants. Clin Perinatol 2013; 40 (04) 753-775
- 39 Escobar GJ, McCormick MC, Zupancic JA. , et al. Unstudied infants: outcomes of moderately premature infants in the neonatal intensive care unit. Arch Dis Child Fetal Neonatal Ed 2006; 91 (04) F238-F244
- 40 Kramer MS, Demissie K, Yang H, Platt RW, Sauvé R, Liston R. ; Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System. The contribution of mild and moderate preterm birth to infant mortality. JAMA 2000; 284 (07) 843-849
- 41 McIntire DD, Leveno KJ. Neonatal mortality and morbidity rates in late preterm births compared with births at term. Obstet Gynecol 2008; 111 (01) 35-41
- 42 Melamed N, Klinger G, Tenenbaum-Gavish K. , et al. Short-term neonatal outcome in low-risk, spontaneous, singleton, late preterm deliveries. Obstet Gynecol 2009; 114 (2 Pt 1): 253-260