What Is Vernix Caseosa?

It’s a common choice for newborns to be bathed shortly after birth once their breathing and temperature have stabilized. In addition to removing blood and amniotic fluid, a bath shortly after birth also wipes away the vernix caseosa—a white, cheese-like substance that acts as a protective layer on your baby’s skin.

Leaving the vernix on your baby's skin may offer some health benefits, so it may be worth considering delaying your infant’s first bath.

This article provides information on the benefits of the vernix caseosa and potentially delaying your baby's first bath.

What Is the Vernix Caseosa?

The vernix caseosa appears as a white, cheese-like substance that acts as a protective layer on your baby’s skin. The coating develops to protect your baby’s skin while they are in the womb. Usually, traces of the vernix remain after childbirth.

The vernix caseosa begins to develop slowly throughout pregnancy and fully develops during the third trimester. The vernix is composed of:

• 80% water
• 10% lipids
• 9% proteins

The lipids and proteins leave the vernix feeling slightly greasy.

Think about when you pour oil into water. The oil collects on the surface of the water instead of mixing together. Water can’t move easily through lipids, so the vernix protects your baby’s fragile skin from pulling in too much water from the amniotic fluid.

It’s the reason your baby’s skin doesn’t come out wrinkled in the way skin gets after a person spends time swimming. The vernix keeps your baby’s skin soft and protects their skin from infection in the womb. 

When the vernix fully develops, it reaches its peak thickness. As you move closer to your due date, the vernix begins to thin. If you have your baby around your due date, there will likely be a thin layer of vernix remaining.

What Are the Benefits?

The primary role of the vernix is to protect and hydrate your baby’s skin. Research shows there may be some additional benefits.

Lubricates the Birth Canal

The waxy texture of the vernix also helps during the birthing process. It helps to reduce friction as your baby moves through the birth canal.

Protects From Infection

Newborns are just starting to develop their immune systems after they are born, meaning they are more susceptible to illnesses. The protective layer formed by the vernix protects your baby from illness in a couple of ways, including:

• The vernix naturally acts as a barrier: The vernix doesn’t allow bacteria to pass through to your baby’s skin right away. This helps your baby adapt to their new surroundings and gives their immune system time to strengthen.
• The vernix contains immuno-peptides, enzymes, and lipids with antimicrobial properties: This protects your baby from pathogens. These also act as antioxidants and reduce inflammation.

Helps Regulate Infant Body Temperature

It can take a while for a baby to regulate their own body temperature out of the womb. It’s one of the reasons your baby is wrapped in blankets and carefully monitored after birth.

Research suggests that leaving the vernix caseosa on your baby’s skin may help them to stabilize their body temperature more quickly. One study showed that leaving the vernix undisturbed reduced the risk of hypothermia and the need to use an incubator for warming.

Reduces Vigorous Crying

Delaying the first bath may reduce vigorous crying in newborns. One study shows that delaying the infant’s first bath and leaving the vernix intact was associated with reduced vigorous crying in newborns.

Maternal Satisfaction

Research suggests that waiting to do the first bath was associated with high satisfaction for mothers. Delaying the first bath allowed more skin-to-skin time with the infant to increase maternal-infant bonding.

In one study, delayed bathing and allowing mothers to assist in their newborn's first bath increased their bond and increased breastfeeding rates.

Should You Delay Your Baby’s First Bath?

You have the option to choose when you would like your infant’s first bath to be. It used to be standard practice for the first bath to occur a couple of hours after delivery, once breathing and temperature were stable.

With the increased research on the benefits of delaying the first bath, recommendations are changing. Some organizations still recommend a minimum of two hours before giving the first bath.

The World Health Organization (WHO) recommends waiting a minimum of six hours after birth before giving the first bath, and preferably waiting a full 24 hours.

One research study recommended a minimum of 12 hours. Still, for the full health benefits of the vernix, they recommend waiting 24 hours.

If you choose to delay the first bath, you can still request for a nurse to use a damp, soft cloth to remove any blood or amniotic fluid left on the infant’s skin from birth. This leaves most of the vernix caseosa intact.

However, you won’t be able to delay bathing your newborn if there is meconium mixed in the amniotic fluid. Meconium is your baby’s first stool. It’s a thick, green substance that lines your infant's intestines during pregnancy.

Rubbing the Vernix Into the Skin

The vernix won’t just sit on top of your newborn’s skin. It will slowly absorb into their skin (just like a thick moisturizer would). You can encourage this by gently rubbing in the vernix over the first 24 to 48 hours.

Any spit-up, saliva, or bowel movements can be gently wiped up with warm water while waiting to give the first bath. And when most of the vernix is absorbed, you can choose to give the first bath and gently wipe away any excess if you choose. 

Summary

The vernix caseosa is a thick, waxy, cheese-like substance that protects your baby in the womb and after they are born. It will slowly absorb into the skin, while providing immune, temperature control, and moisturizing benefits. Speak with your healthcare provider about potentially delaying your baby's first bath.

A Word From Verywell

The vernix caseosa may be a little alarming to look at, but delaying your newborn’s first bath does come with some potential benefits. If you choose to delay the first bath, talk with your healthcare team and add it to your birth plan to prevent an accidental bath if your wishes aren’t known.