NICU admission hypothermia, chorioamnionitis, and cytokines

Abstract

Objective: To determine whether neonatal intensive care unit (NICU) admission hypothermia is associated with an intrauterine inflammatory response.

Methods: We analyzed a cohort of 309 very low birthweight infants to determine relationships between admission hypothermia, chorioamnionitis, and serum and cerebrospinal fluid (CSF) interleukin (IL)-1β, IL-6, and tumor necrosis factor-α.

Results: Admission hypothermia <36°C occurred in 72% of patients <26 weeks and 44% of patients ≥26 weeks gestational age. NICU admission hypothermia was not associated with histologic chorioamnionitis or with elevated serum cytokine concentrations. CSF IL-6 concentrations ≥6.3 pg/mL were associated with admission hypothermia in infants <26 weeks' gestation. Clinical chorioamnionitis was associated with a lower risk of admission hypothermia, while cesarean section delivery was associated with increased risk.

Conclusions: NICU admission hypothermia is common among preterm infants and is not associated with the fetal inflammatory response syndrome. Hypothermia is less common in the setting of clinical chorioamnionitis and more common in cesarean section deliveries, identifying two groups in whom extra attention to appropriate thermoregulation is warranted.

Figure 1. NICU admission hypothermia as a function of gestational age

NICU admission temperatures were recorded in 309 very low birth weight infants. Mean temperature (°C) ± SD at each gestational age in weeks is shown on the left. Number of patients at each gestational age with “hypothermia” (<36°C) versus “normothermia” (≥36°C) on NICU admission is shown on the right. NICU= neonatal intensive care unit.