Neonatal Hypoxia in Term Infants

Abstract

INTRODUCTION: To determine the demographic, obstetrical, intrapartum and perinatal factors associated with neonatal hypoxia. METHODS: Of singleton pregnancies delivered at term in 2013; 46 (0.6%) cases identified as neonatal hypoxia were compared to 8273 neonates (controls). Analysis utilized Chi-square, student T test and regression analysis. RESULTS: Prenatal factors associated with increased risk of neonatal hypoxia included higher BMI, unmarried mothers, smoking, severe preeclampsia, GBS+ and birth defects. Intrapartum factors that increased the risk of neonatal hypoxia included late decelerations, fetal tachycardia, maternal fever, chorioamnionitis, abnormal fetal heart rate (FHR), primary cesarean section (C/S), and the use of magnesium sulfate, nifedipine, gentamycin or clindamycin in labor. Mothers of hypoxic neonates had more blood loss and longer hospital stay. Neonates with hypoxia had lower Apgar scores, umbilical cord gases trending towards acidosis, and more NICU admission. Associated morbidity with neonatal hypoxia included pulmonary disease (91%), hypoxic ischemic encephalopathy (76%), jaundice (70%), birth defects (65%), nutrition disorders (40%), electrolyte derangements/dehydration (26%), neurological dysfunction (20%), sepsis (20%), and hematological disorders (20%). Regression analysis showed that independent predictors of neonatal hypoxia were maternal fever (P=.001, odds ratio [OR]=6.151); severe preeclampsia (P=.003, OR=6.921); birth defects (P=.000, OR=5.962); smoking (P=.011, OR=3.595); primary C/S (P=.045, OR 2.0); abnormal FHR coding (P=.001 OR=3.12). CONCLUSION: Severe preeclampsia and intrapartum infection are major predictors of neonatal hypoxia and should be targets of preventive efforts. Additionally, measures to reduce maternal smoking, the safe reduction of primary C/S, effective prenatal diagnosis, and appropriate management of intrapartum fetal stress conditions may facilitate the prevention of neonatal hypoxia.