Newborn-oriented and environmental factors for newborns' skin barrier functions

Aim This study aimed to examine newborn-oriented and environmental factors of newborn skin barrier functions. Methods This was a retrospective secondary analysis of 227 newborns from a previous study. Newborn skin barrier functions were measured on the fourth day after birth via the following parameters: stratum corneum hydration, transepidermal water loss, skin pH, and sebum secretion. Skin barrier functions were measured at four body sites; their averaged values were used for the analysis. The associations among skin barrier functions, newborn-oriented factors, and environmental factors were evaluated. Multiple regression analysis was performed using a forced entry method, and independent variables for which p-values were t test, analysis of variance, and Pearson's correlation analysis were included. Results A total of 211 participants were analyzed. The mean +/- standard deviation values of stratum corneum hydration, transepidermal water loss, skin pH, and sebum secretion were 28.58 +/- 8.40 and 7.28 +/- 2.02 g/m(2)/h, 5.77 +/- 0.53, and 23.59 +/- 15.89 mu g/cm(2), respectively. Newborn-oriented factors (gestational days, weight, amount of vernix, and parity) and environmental factors (birth season) were significantly associated with one or more skin barrier functions. Conclusions Newborn-oriented (including labor- and delivery-related) and environmental factors were associated with the skin barrier functions. The newborn maturity level, newborn sex, environmental temperature, and humidity may affect skin barrier functions in newborns. Further studies should focus on the effects of these factors on newborn skin barrier assessments, and develop tailored skincare strategies based on their characteristics.