The Vernix Caseosa - the impressive Latin name for what actually means "cheesy coating". The cheesy coating referred to is the white waxy layer that is covering a newborn baby. The vernix is sometimes neglected as something that just looks quite repulsive and is cleansed off straight away, before handing a clean baby to the mother. There are, however, several reasons why you want to keep the vernix and let it slowly be soaked in by the skin.
The vernix develops in the womb throughout pregnancy and peaks during the last trimester. In the womb it has the function of protecting the fetus from taking in too much of the amniotic fluids as well as giving away too much water and minerals - so called trans epidermal water loss (TEWS). If a baby is delivered on the due date there is usually a thin layer of vernix left. Premature babies have a thicker layer and overdue babies usually have less. Before being useful outside the womb it has the excellent quality of working as lubrication for vaginal birthing.
It is not hard to imagine that birth is a time in life of extremely high oxidative stress. The high amount of antioxidants in the vernix are believed to be there in order to help in a pro-oxidative environment. This means that the vernix is protecting the baby from, among other things, pollutants and UV radiation.
Since the immune system of a newborn is not yet fully developed, babies are more susceptible to pathogens than a two-year-old. The vernix is immune supporting both by acting as a physical barrier for foreign bacteria and viruses to enter. But it also has anti-microbial as well as anti-inflammatory properties.
Folding newborns in blankets and putting on a hat is not just something we do because it looks so cute. The completely new task of temperature regulation is especially difficult for babies with low birth weight. We fold them in a blanket to provide warmth in order not to drop in body temperature. It has also been shown in clinical studies that the vernix helps in stabilizing body temperature by being a protective barrier of fat.
However, temperature regulation is by far the only new task for a newborn. When imagining the difference of moistness in the womb vs outside in the air it is easy to understand why an infant's skin easily gets dehydrated and flaky during the first weeks of life. The vernix acts as the best moisturizer, protection of the skin barrier (extra important since the outer layer has not yet been fully developed at this stage) and wound healing.
With all the amazing benefits of the vernix we find it a little unfair that it is named by the cheesy look and believe it deserves more attention. Leaving the vernix on the skin until it is absorbed is an easy way to give your baby a little extra support during the first weeks of life.