Vernix caseosa, usually just called vernix, is the white, creamy, waxy coating on a newborn's skin. It forms on the fetus during pregnancy, protects the skin from the amniotic fluid in the womb, and after birth works as a natural moisturizer and barrier while your baby's skin adjusts to the air. It's normal and harmless, and it doesn't need to be scrubbed off.
The name is Latin: vernix means varnish and caseosa means cheesy, which describes how it looks.
What Is Vernix Made Of?
Vernix is mostly water. A review in the Indian Journal of Dermatology puts its makeup at about 81% water, 9% lipids (fats), and 10% protein. Under a microscope, it's made of water-filled skin cells shed by the fetus, held in a waxy matrix of fats from the fetal oil glands.
- Lipids: ceramides, cholesterol, free fatty acids, wax esters, triglycerides, and squalene, many of the same fats that make up the outer layer of skin.
- Proteins: including natural antimicrobial proteins such as LL-37, lysozyme, lactoferrin, and defensins.
When Does Vernix Form?
Vernix starts forming around 21 weeks of pregnancy, about halfway through, as the fetus sheds skin cells that mix with oil from its sebaceous glands. Those glands are most active in the third trimester, so that's when vernix builds up. Fine body hair called lanugo helps hold it on the skin.
What Does Vernix Do?
Before Birth
For months, your baby floats in amniotic fluid. Vernix acts as a water-repellent layer that keeps the skin from getting waterlogged while it develops. It may also reduce friction as the baby moves through the birth canal.
After Birth
- Moisturizes: It helps the skin hold on to water as it moves from a wet environment to dry air.
- Protects: Its antimicrobial proteins are part of the skin's first line of defense against germs.
- Supports healing: Researchers have studied its role in skin repair and wound healing.
You may read that vernix keeps babies warm. That one is less certain: the same review notes that studies disagree about whether it has a meaningful effect on temperature. What clearly helps keep a newborn warm is drying them off, skin-to-skin contact, and covering their head.
How Much Vernix Is Normal?
There's no single normal amount. Some babies are coated head to toe, while others have a little in the creases of the neck, armpits, and groin, or none you can see. A 2022 study of 422 newborns at a hospital in Ethiopia found visible vernix on about 55% of babies (Mesfin et al.).
The biggest factor is timing:
- Born early: Babies born before their due date tend to have more vernix.
- Born at or past the due date: Vernix thins out toward the end of pregnancy, so these babies often have less. Cleveland Clinic notes that babies born past their due date tend to have more peeling skin for that reason. The peeling is usually harmless.
- Girls: Some studies have found girls are a little more likely to have vernix than boys.
So a baby born with lots of vernix, or with little or none, is usually just showing how far along the pregnancy was. It isn't a measure of health on its own.
What Color Should Vernix Be?
Vernix is normally white or off-white. If it looks yellow or greenish, it may be stained by meconium, the baby's first stool passed before birth. Your care team checks for this at delivery, so mention it if you notice it and aren't sure it's been seen.
Should You Wipe Vernix Off or Leave It On?
Leave it on. The World Health Organization recommends that bathing be delayed until 24 hours after birth, or for at least 6 hours if a full day isn't possible for cultural reasons. Your baby is still dried off and wiped clean of blood and fluid at birth. The vernix just doesn't need to be scrubbed away.
Waiting has other benefits. Cleveland Clinic reports that a study found delaying the first bath at least 12 hours raised exclusive breastfeeding rates, and that in one survey 87% of US hospitals delay newborn baths by at least 6 hours. The delay also leaves more time for skin-to-skin contact and keeps your baby warmer in the first hours.
Your team may bathe or clean a baby sooner for medical reasons, and that's their call to make.
What to Do With It
- Leave thin layers alone. They'll be absorbed or rub off on their own.
- If there are thick patches in skin folds, you can gently massage them into the skin like lotion.
- Don't scrub. Newborn skin is delicate.
Left alone, most vernix is gone within the first few days. The review above notes that it has usually separated by about day 5, a little longer in the skin folds.
Add It to Your Birth Plan
If delayed bathing matters to you, write it down and mention it to your nurse when you arrive. For example:
- "Please delay our baby's first bath for at least 24 hours."
- "Please dry the baby but leave the vernix on the skin."
Our guide on how to create a birth plan covers other newborn-care preferences worth deciding ahead of time.
Frequently Asked Questions
What is the white stuff on babies when they're born?
It's vernix caseosa, a natural coating of water, fats, and skin cells that protected your baby's skin in the womb.
What is the greasy substance that protects a fetus in utero and can still be present at birth?
Vernix caseosa. It forms from about mid-pregnancy and is often still on the skin at birth.
Do C-section babies have vernix?
Yes. Vernix forms in the uterus, so babies born by C-section have it too. Studies disagree on whether they keep more of it: one found more coverage after cesarean births, while the 2022 Ethiopian study found no difference by delivery method.
What does it mean if a baby is born with lots of vernix?
Usually that the baby was born a bit earlier in the third trimester, before the vernix thinned out. It's normal.
What if my baby was born without vernix?
That's common in babies born at or after their due date, and it isn't a problem by itself. Some dry, peeling skin in the first weeks is normal.
Does vernix have a smell?
There's little research on how vernix itself smells. What matters more is that a foul smell at birth isn't expected. A bad-smelling discharge or amniotic fluid can be a sign of an infection called chorioamnionitis, so tell your care team if you notice one.
How long does vernix take to absorb?
A few days. Most is gone within about five days if you leave it on, with a little lingering in skin folds.
A doula can help you write newborn-care preferences like delayed bathing into your birth plan and remind the team of them in the moment. You can compare doulas near you on Bornbir, read their reviews, and message them directly.