Risk of Neonatal Neurologic Morbidity in Advancing Term GestationsFunding This project was supported in part by a Robert Wood Johnson Foundation Physician Faculty Scholar Award (A.G.C.).
04 May 2017
29 November 2017
29 December 2017 (eFirst)
Objective Placental insufficiency is associated with neonatal neurologic morbidity and late-term gestations (410/7–416/7 weeks). Whether late-term infants are at increased risk of neurologic morbidity compared with term infants (390/7–406/7 weeks) remains unclear. We aim to compare risk of neurologic morbidity among late-term and term infants.
Study Design This secondary analysis of a single-institution prospective cohort study included all liveborn, nonanomalous singleton term and late-term infants, with data on adverse neonatal outcomes up until 28 days of life. The primary outcome was a neonatal neurologic morbidity composite, defined by having one of these conditions: neonatal seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, and neonatal hypothermic therapy. Secondary outcomes were the composite's individual components and nonneurologic neonatal morbidity. Multivariable logistic regression adjusted for delivery mode, nulliparity, and labor type.
Results Of 5,529 infants included, 747 were late term and 4,782 were term. The risk of composite neurologic morbidity was not significantly different among late-term or term infants (0.5 vs. 0.6%; adjusted odds ratio: 0.59, 95% confidence interval: 0.21–1.71). Overall neonatal morbidity was not significantly different in the two groups, though late-term infants had a nonsignificantly higher prevalence of respiratory distress syndrome (5.5 vs. 3.3%) and meconium aspiration syndrome (0.7 vs. 0.2%).
Conclusion Neonatal neurologic morbidity is uncommon after 39 weeks. Risk does not increase after 41 weeks.
- 1 Stoll BJ, Hansen NI, Bell EF. , et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network. Pediatrics 2010; 126 (03) 443-456
- 2 Altman M, Vanpée M, Cnattingius S, Norman M. Neonatal morbidity in moderately preterm infants: a Swedish national population-based study. J Pediatr 2011; 158 (02) 239-244
- 3 Cheng YW, Kaimal AJ, Bruckner TA, Halloran DR, Caughey AB. Perinatal morbidity associated with late preterm deliveries compared with deliveries between 37 and 40 weeks of gestation. BJOG 2011; 118 (12) 1446-1454
- 4 Bruckner TA, Cheng YW, Caughey AB. Increased neonatal mortality among normal-weight births beyond 41 weeks of gestation in California. Am J Obstet Gynecol 2008; 199 (04) 421.e1-421.e7
- 5 Cheng YW, Nicholson JM, Nakagawa S, Bruckner TA, Washington AE, Caughey AB. Perinatal outcomes in low-risk term pregnancies: do they differ by week of gestation?. Am J Obstet Gynecol 2008; 199 (04) 370.e1-370.e7
- 6 Seikku L, Gissler M, Andersson S. , et al. Asphyxia, neurologic morbidity, and perinatal mortality in early-term and postterm birth. Pediatrics 2016; 137 (06) e20153334
- 7 Moster D, Wilcox AJ, Vollset SE, Markestad T, Lie RT. Cerebral palsy among term and postterm births. JAMA 2010; 304 (09) 976-982
- 8 Zhang X, Kramer MS. Variations in mortality and morbidity by gestational age among infants born at term. J Pediatr 2009; 154 (03) 358-362
- 9 Non-Medically IE-TD. ; American College of Obstetricians and Gynecologists. ACOG committee opinion no. 561: nonmedically indicated early-term deliveries. Obstet Gynecol 2013; 121 (04) 911-915
- 10 American College of Obstetricians and Gynecologists. Practice bulletin no. 146: Management of late-term and postterm pregnancies. Obstet Gynecol 2014; 124 (2 Pt 1): 390-396
- 11 Divon MY, Haglund B, Nisell H, Otterblad PO, Westgren M. Fetal and neonatal mortality in the postterm pregnancy: the impact of gestational age and fetal growth restriction. Am J Obstet Gynecol 1998; 178 (04) 726-731
- 12 Donovan EF, Besl J, Paulson J, Rose B, Iams J. ; Ohio Perinatal Quality Collaborative. Infant death among Ohio resident infants born at 32 to 41 weeks of gestation. Am J Obstet Gynecol 2010; 203 (01) 58.e1-58.e5
- 13 Caughey AB, Musci TJ. Complications of term pregnancies beyond 37 weeks of gestation. Obstet Gynecol 2004; 103 (01) 57-62
- 14 Caughey AB, Washington AE, Laros Jr RK. Neonatal complications of term pregnancy: rates by gestational age increase in a continuous, not threshold, fashion. Am J Obstet Gynecol 2005; 192 (01) 185-190
- 15 Executive summary: neonatal encephalopathy and neurologic outcome, second edition. Report of the American College of Obstetricians and Gynecologists' Task Force on Neonatal Encephalopathy. Obstet Gynecol 2014; 123 (04) 896-901
- 16 Spain JE, Tuuli MG, Macones GA, Roehl KA, Odibo AO, Cahill AG. Risk factors for serious morbidity in term nonanomalous neonates. Am J Obstet Gynecol 2015; 212 (06) 799.e1-799.e7
- 17 Tuuli MG, Stout MJ, Shanks A, Odibo AO, Macones GA, Cahill AG. Umbilical cord arterial lactate compared with pH for predicting neonatal morbidity at term. Obstet Gynecol 2014; 124 (04) 756-761
- 18 Committee on Obstetric Practice, the American Institute of Ultrasound in Medicine, and the Society for Maternal-Fetal Medicine. Committee Opinion No 700: methods for estimating the due date. Obstet Gynecol 2017; 129 (05) e150-e154
- 19 Malone A, Ryan CA, Fitzgerald A, Burgoyne L, Connolly S, Boylan GB. Interobserver agreement in neonatal seizure identification. Epilepsia 2009; 50 (09) 2097-2101
- 20 Jacobs SE, Berg M, Hunt R, Tarnow-Mordi WO, Inder TE, Davis PG. Cooling for newborns with hypoxic ischaemic encephalopathy. Cochrane Database Syst Rev 2013; CD003311 (01) DOI: 10.1002/14651858.CD003311.pub3.
- 21 Creasy RK, Resnik R, Iam JD. , et al. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice, 7th ed. Vol. 7. Philadelphia, PA: Elsevier Saunders; 2014
- 22 American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 134: fetal growth restriction. Obstet Gynecol 2013; 121 (05) 1122-1133
- 23 Redline RW, Boyd T, Campbell V. , et al; Society for Pediatric Pathology, Perinatal Section, Maternal Vascular Perfusion Nosology Committee. Maternal vascular underperfusion: nosology and reproducibility of placental reaction patterns. Pediatr Dev Pathol 2004; 7 (03) 237-249
- 24 Gülmezoglu AM, Crowther CA, Middleton P, Heatley E. Induction of labour for improving birth outcomes for women at or beyond term. Cochrane Database Syst Rev 2012; (06) CD004945
- 25 Bai J, Wong FW, Bauman A, Mohsin M. Parity and pregnancy outcomes. Am J Obstet Gynecol 2002; 186 (02) 274-278
- 26 Sibai BM. Chronic hypertension in pregnancy. Obstet Gynecol 2002; 100 (02) 369-377
- 27 Watson D, Rowan J, Neale L, Battin MR. Admissions to neonatal intensive care unit following pregnancies complicated by gestational or type 2 diabetes. Aust N Z J Obstet Gynaecol 2003; 43 (06) 429-432