Vernix Caseosa

For many first time mums, the patches of white, waxy coating on their newly born baby's skin can be worrying. This oily substance is actually nothing to worry about and is known as vernix caseosa, a creamy substance that coats the skin of newborn babies during their growth in utero.

Having your newborn delivered with a patches or a layer of vernix caseosa still remaining on their skin is fairly common. Most babies are born with a least some patches of the substance still present on the skin. It is thought that vernix caseosa has many beneficial aspects, including protecting the newborn's skin by keeping it moisturised and helping the baby conserve heat. It also has a possible anti-bacterial effect.

What exactly is it?

Vernix caseosa comes from two Latin words, with vernix translating into 'varnish' and caseosa meaning 'cheesy'. The substance is produced naturally by the sebaceous glands while the baby is in the womb during the second trimester of pregnancy and is made up of natural oils and sloughed off skin cells - hence why it looks waxy and has a creamy, white colour.

When does it appear?

Vernix caseosa starts to appear around the 19th or 20th week of pregnancy and can stay on the baby's skin until he or she matures and is ready to be born. Around this time in the pregnancy, you will probably be invited for a more detailed ultrasound scan. The baby is now around 14 to 15 cms long from crown to rump and will probably weigh around 230 to 240gs. The baby's senses are developing rapidly now and some hair may be growing on the baby's head. One of the great aspects of this time as a new mum is starting to feel your baby move around in the womb, which at first may feel like butterflies fluttering around. The next 10 weeks or so are a time of great development for your baby and you will start to feel more like a mum.

What does it do?

Your baby develops this waxy coating as a way to protect its skin from its surroundings. While growing in your womb, your baby is surrounded by amniotic fluid which is designed to protect your baby while it develops. However, floating in amniotic fluid for nine months can be hard on a baby's skin, so the vernix caseosa is designed to protect the skin and keep it moisturised. After delivery you will see for yourself just how soft your baby's skin is. The reason for this softness is vernix caseosa.

It has often been thought that the substance has some sort of healing properties and doctors have recently discovered that there are certain proteins in the oils that do, in fact, have antibiotic properties. The thick substance also acts as a barrier to anything nasty reaching baby's skin and keeps it safe.

Vernix caseosa also works as a sort of cleanser, cleaning your baby's skin while in the womb. It is thought to do a better job than many store-bought cleansers. Of course, by far the greatest benefit of vernix caseosa for many anxious mums-to-be is that the waxy coating also helps to make the baby more slippery, acting as a natural lubricant to aid the baby's journey through the birth canal during delivery.

Why do newborns still have the coating at birth?

When you hold your newborn baby for the first time, there is a large likelihood that he or she will still have a large amount of vernix caseosa still obvious on the skin. This is nothing to worry about and is completely natural. Despite the journey down the birth canal, much of the substance will still remain on the skin, however it can be washed off easily during the baby's first bath.

As the lungs develop and mature in the third trimester, more amniotic fluid is produced, so the vernix caseosa is working harder to protect your baby's skin. As your baby matures, the coating will start to diminish, which is why some premature babies have a large amount of vernix caseosa on their skin at delivery and many post-mature babies have very little or none remaining on their skin at birth.

So while it seems a little strange, this waxy coating is actually working hard to keep our newborns safe and protect their delicate skin before birth.