Intrapartum fever and chorioamnionitis as risks for encephalopathy in term newborns: a case–control study

Abstract

In this study we examined the relationship between diagnoses of isolated intrapartum fever or chorioamnionitis and the risk of encephalopathy in term newborns. We conducted a populationbased, case-control study in Washington State using 1994 to 2002 linked data from the Washington State Birth Registry and the Comprehensive Hospital Abstract Reporting System (CHARS). We identified 1060 singleton, term newborns (602 males, 458 females) with International Classification of Diseases (ICD-9) diagnoses consistent with encephalopathy, and 5330 unaffected control newborns (2756 males, 2574 females). Intrapartum fever was defined by a diagnosis of intrapartum temperature of >38˚C in the birth registry or CHARS databases. Chorioamnionitis was defined using ICD-9 diagnoses recorded in CHARS. We identified 2.2 cases of encephalopathy per 1000 births. Isolated intrapartum fever was associated with a 3.1-fold (95% confidence interval [CI] 2.3-4.2) increased risk of newborn encephalopathy. Chorioamnionitis was associated with a 5.4-fold (95% CI 3.6-7.8) increased risk of encephalopathy. We found that isolated intrapartum fever and chorioamnionitis were independently associated with an increased risk of encephalopathy in term infants. Our data also indicate that there is a spectrum of risk for encephalopathy in term infants exposed to intrapartum fever. Infants born to women with signs of chorioamnionitis other than isolated intrapartum fever may be at higher risk of encephalopathy than those exposed only to isolated intrapartum fever.

Inflammation‐induced sensitization of the brain in term infants

“…In addition, clinical chorioamnionitis was associated with a more than fivefold increased risk of neonatal encephalopathy by Blume et al 29 in a retrospective, population-based study; however, histological findings were not reported. A recent study from the Netherlands examined the associations between placental pathology and the patterns of brain injury, as detected by magnetic resonance imaging (MRI), amongst term-born infants diagnosed with neonatal encephalopathy.…”

“…28 Neither maternal fever nor clinical chorioamnionitis has been found to accurately predict histological findings. 29 In its severest form, membrane inflammation involves the cord (funisitis), with vasculitis of the umbilical vessels and the presence of fetal neutrophilic granulocytes indicating activation of the fetal inflammatory response. Fetal inflammatory responses have been associated with neurological impairment in both term-born and preterm infants.…”

“…8,9,29 In a prospective cohort study, maternal fever (≥37.5°C) was associated with an increased risk of neonatal encephalopathy (odds ratio [OR] of 10.8, 95% confidence interval [CI] 4-29.3). 31 However, there is evidence that this risk may be increased in the presence of chorioamnionitis and fetal acidosis.…”

Incidence of and Risk Factors for Neonatal Respiratory Depression and Encephalopathy in Rural Sarlahi, Nepal

“…Cases were not excluded from classification as IPR if the criteria for infection were met, because clinical observations for infection were made after childbirth, during the first home visit, and we desired to characterize the potential interaction between neonatal infections and intrapartum hypoxia in the development of NE. [15][16][17] We further ascertained the subset of cases of probable IPR NRD that progressed to NE. NE was defined on the basis of neurologic abnormalities observed in the first 7 days of life (seizures or 2 of the following: lethargy, poor suck, or respiratory depression, defined as a respiratory rate of Ͻ40 breaths per minute, as measured by the study worker).…”

“…To our knowledge, this is the first population-based estimate of the incidence of NE from a community-based cohort in a developing country. With the assumption of a 30% disability rate among survivors of NE, 16,17 the impair- (14) 42 (10) 12 (11) 1385 (7) Hypoxic-ischemic intrapartum events may contribute to 30% to 80% of cases of NE. 30,[35][36][37] In Perth, Australia, 30% of NE cases had evidence of intrapartum hypoxia, defined on the basis of abnormal fetal heart rates, meconium staining, and low Apgar scores.…”