Negative Temperature Differential in Preterm Infants Less Than 29 Weeks Gestational Age: Associations With Infection and Maternal Smoking.

BACKGROUND: Hypothermia is related to increased morbidity and mortality in very preterm infants; continuous temperature monitoring is necessary. Thermoregulation is limited in preterm infants. OBJECTIVES: The purpose of the research was to assess and describe negative temperature differential (NTD) and assess the associations of NTD with infant demographic characteristics, medical history, and clinical events. METHODS: An exploratory, case study design was used. Abdominal and foot temperature was measured every minute over the first 2 weeks of life in 22 preterm infants at less than 29 weeks gestational age. RESULTS: All infants experienced NTD. Daily NTD in all infants across all study days ranged from 0 to 70.7%; 2-week mean NTD over all infants ranged from 7.3% to 38.5%. Four infants treated for late onset of infection had a higher NTD than 18 infants without infection (M = 27.8%, SD = 9.52 vs. M = 16.4%, SD = 5.34, p < .05). Although not statistically significant, higher mean percentage of NTD was noted in infants having early onset infection (24.1% vs. 16.4%), African American race (20.0% vs. 15.3%), and/or being born to a mother who smoked during pregnancy (26.6% vs. 16.7%). DISCUSSION: A larger study is needed to examine associations between NTD and race, maternal smoking history, and infection. NTD might be used as a biomarker to guide acute clinical care and identify infants at risk for acute and chronic morbidity.