© 2017 Nature America, Inc., part of Springer Nature. Objective:The objective of the study was to compare thoracic fluid content (TFC) between newborn infants with and without respiratory distress. We tested the hypothesis that TFC would be higher in infants with respiratory distress.Study Design:A total of 96 newborn infants, gestational age 37.9 (2.6) weeks, were enrolled at birth. TFC by electrical bioimpedance was recorded within 3 h after birth (TFC1) and at 24 h of life (TFC2).Results:TFC1 was higher in infants with respiratory distress at birth (76.8 (24.9) versus 61.6 (16.1) 1 KOhm â '1, P <0.0005). The association was independent from gestational age and mode of delivery. TFC2 was independently associated with respiratory distress at 24 h of life (adjusted coefficient b=0.5 (s.d. 0.02), P=0.02).Conclusion:TFC by electric bioimpedance independently correlated with the presence of respiratory distress at birth and at 24 h of life in late preterm and term newborn infants.