Changes in the water content of the skin during the early neonatal period

The skin state of neonates has not been adequately investigated. To clarify the characteristics of neonate skin and provide effective cleanliness care, we measured the water content of neonate skin every day, and evaluated its daily changes and differences among areas of the body. In 39 full-term neonates, the water content of the corneal layer of the epidermis was measured using a corneometer in 6 areas of the body (between the eyebrows, corner of the mouth, middle of the forearm, abdomen, infrascapular area, and the lateral side of the thigh) from the 1st to 5th days after birth. The water content of the neonate skin was the lowest on the 1st day after birth and increased with days after birth in 5 areas of the body after excluding the corner of the mouth. The water content of the skin differed among the areas, being the highest in the corner of the mouth and lowest in the forearm. Comparison between the above neonates on the 1st day after birth and 20 adult females showed significantly lower water contents in all 6 areas in the former (p < 0.001). The rate of increase in the skin water content was higher in neonates weighing < 3,000 g at birth than in those weighing ≥ 3,000 g. The water content of the skin was slightly higher in neonates born at ≥ 40 gestational weeks than in those born at 40 gestational weeks. There were no sex-related differences in measurement values in each area In skin care for neonates showing marked daily changes, the low water content of the skin should be maintained to help the formation of a healthy corneal layer of the epidermis.