Ambient humidity influences the rate of skin barrier maturation in extremely preterm infants

ObjectivesTo test the hypothesis that the level of relative humidity (RH) in which preterm infants are nursed might influence their postnatal skin maturation.Study designIn 22 preterm infants (GA 23-27 weeks), transepidermal water loss (TEWL) was determined at postnatal ages (PNA) of 0, 3, 7, 14, and 28 days. At a PNA of 7 days, the infants were randomized to care at either 50% or 75% RH.ResultsTEWL decreased at a slower rate in infants nursed at the higher RH. At a PNA of 28 days, TEWL was about twice as high in infants nursed at 75% RH (22 ± 2 g/m2 h) than in those nursed at 50% RH (13 ± 1 g/m2 h; P < .001).ConclusionsThe results indicate that the level of RH influences skin barrier development, with more rapid barrier formation in infants nursed at a lower RH. The findings have an impact on strategies for promoting skin barrier integrity in extremely preterm infants.