When a baby is born not everything is all fully developed and will still take some time to reach levels that are resilient. This is true of the skin, especially in babies that are prematurely born.

A study out of Italy went to dig into what happens to the skin at and around the time of birth.

They said, in the late neonatal period, about 50% of all deaths are related to sepsis or other severe infections, and the incompetent epidermal barrier can be considered a major predisposing factor for neonatal sepsis development.

There is a decrease in skin permeability with age, and infants of 37 weeks gestational age show no drug transcutaneous absorption and a good skin barrier function.

According to the researchers, at birth, the skin surface is rougher and dryer compared with older children. During the first 30 days of life, skin smoothing is correlated to an increase in skin hydration.  Infant skin has a higher rate of water absorption and desorption compared with adults.

Infant skin pH levels are higher than those of adult skin, which is usually characterized by a pH value between 5 and 5.5.

Neonates less than 28 weeks of gestational age and those that have a low birth weight have an immature epidermal barrier and also lack the protective coating of vernix caseosa; therefore, they have a greater risk of having a lower temperature.

Just like in the rest of the body there is a microbiome in the skin where good bacteria protects the body. Given that infant skin is more hydrated than adult skin, the skin microbiome of newborns resembles the microbiome of moist skin sites in adults.

Newborns have a large surface area in relation to volume and a high thermal conductance with an increased risk of heat loss.

Read the full study for more details.

http://www.ncbi.nlm.nih.gov/pubmed/26487977