Neonatal encephalopathy and the association to asphyxia in labor

• Published in: American journal of obstetrics and gynecology Vol. 211; no. 6; pp. 667.e1 - 667.e8
• Main Authors: Jonsson, Maria, MD, PhD, Ågren, Johan, MD, PhD, Nordén-Lindeberg, Solveig, MD, PhD, Ohlin, Andreas, MD, PhD, Hanson, Ulf, MD, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2014
• Subjects: admission CTG pattern; Adult; asphyxia; Asphyxia - blood; Asphyxia - epidemiology; Brain Diseases - epidemiology; Cardiotocography; encephalopathy; Female; Fetal Blood - chemistry; Heart Rate, Fetal - physiology; Humans; Hydrogen-Ion Concentration; Hypoxia-Ischemia, Brain - blood; Hypoxia-Ischemia, Brain - epidemiology; hypoxic; Infant, Newborn; Infant, Newborn, Diseases - epidemiology; ischemic; labor; Male; neonatal encephalopathy; Obstetric Labor Complications - blood; Obstetric Labor Complications - epidemiology; Obstetrics and Gynecology; Pregnancy; Retrospective Studies; Severity of Illness Index; ischemic; hypoxic; admission CTG pattern; neonatal encephalopathy; encephalopathy; asphyxia; labor
• ISSN: 0002-9378; 1097-6868; 1097-6868
• DOI: 10.1016/j.ajog.2014.06.027

Objective In cases with moderate and severe neonatal encephalopathy, we aimed to determine the proportion that was attributable to asphyxia during labor and to investigate the association between cardiotocographic (CTG) patterns and neonatal outcome. Study Design In a study population of 71,189 births from 2 Swedish university hospitals, 80 cases of neonatal encephalopathy were identified. Cases were categorized by admission CTG patterns (normal or abnormal) and by the presence of asphyxia (cord pH, <7.00; base deficit, ≥12 mmol/L). Cases with normal admission CTG patterns and asphyxia at birth were considered to experience asphyxia related to labor. CTG patterns were assessed for the 2 hours preceding delivery. Results Admission CTG patterns were normal in 51 cases (64%) and abnormal in 29 cases (36%). The rate of cases attributable to asphyxia (ie, hypoxic ischemic encephalopathy) was 48 of 80 cases (60%), most of which evolved during labor (43/80 cases; 54%). Both severe neonatal encephalopathy and neonatal death were more frequent with an abnormal, rather than with a normal, admission CTG pattern (13 [45%] vs 11 [22%]; P  = .03), and 6 [21%] vs 3 [6%]; P  = .04), respectively. Comparison of cases with an abnormal and a normal admission CTG pattern also revealed more frequently observed decreased variability (12 [60%] and 8 [22%], respectively) and more late decelerations (8 [40%] and 1 [3%], respectively). Conclusion Moderate and severe encephalopathy is attributable to asphyxia in 60% of cases, most of which evolve during labor. An abnormal admission CTG pattern indicates a poorer neonatal outcome and more often is associated with pathologic CTG patterns preceding delivery.