Vernix caseosa. Development, physiology, function and effect of early bathing of the newborn

Vernix caseosa is a protective biofilm covering the fetus during the last trimester. It is mainly composed of water (80.5%), proteins (10.3%) and lipids (9.1%). Earlier reports have focused primarily on its lipid components, derived from sebaceous glands and stratum corneum. Recent studies have revealed that vernix also contains antimicrobial polypeptides. In addition to its barrier properties, vernix may therefore serve an active biologic role in protecting the newborn against microbial invasion. However, these reports do not seem to have altered current practice in neonatal care. Our aim was to investigate available data, to see if a conclusion regarding the timing of the newborn s first bath could be drawn. Concern for newborn thermoregulation has traditionally driven bathing practices. Several different studies over the last years indicate that the timing of the first bath for healthy term newborns does not negatively affect temperature stability. This has resulted in a tendency to earlier neonatal bathing, due to fear of transmission of HIV and hepatitis B. In Norway, however, pregnant women are screened for HIV/ hepatitis B, and precautions are taken when necessary. It has further been shown that bathing has minimal effect on bacterial colonization of skin. We have not been able to find any data supporting the practice of early neonatal bathing. Leaving vernix on newborn skin until spontaneous drying is favorable due to its protective and moisturizing properties. Taken into account that most of vernix is removed during bathing, we find it advisable to postpone the newborns first bath until after 24 hours