What is Vernix Caseosa? How Long To Leave It On Baby?

What is vernix caseosa? Why do babies have it on their skin – and when should you clean it off? Today, we’ll cover everything parents need to know about vernix caseosa.

When a baby is just born, you’ll likely notice that they’re covered in a white substance that looks a bit like cheese. This is vernix caseosa. But why do babies have this on their skin? How does it benefit baby – and when should you clean it off? Today, we’ll cover everything parents need to know about vernix caseosa.

What is vernix caseosa?

Vernix caseosa (sometimes just called the vernix) is a coating that develops and covers baby while they’re in the womb.

It is made up of fats, proteins, and skin cells.

It is white and looks like cheese – and its name comes from these characteristics. (“Vernix” comes from a Latin word meaning “varnish,” and “caseosa” comes from a Latin word meaning “cheesy” or “cheese-like.”)

Main purpose of vernix caseosa

The main reason why babies have vernix caseosa is to keep their skin from wrinkling while they’re in the womb.

If they didn’t have vernix caseosa, the constant exposure to amniotic fluid would wrinkle or chap their skin, kind of like how our own skin gets wrinkled after bathing or swimming.

Vernix caseosa starts to coat baby around the twentieth week of pregnancy. It keeps thickening until around week 34, when it starts to shed into the amniotic fluid. By week 40 (the due date), most of the vernix has vanished.

So, if baby is born very close to their due date, they’ll probably have just a bit of vernix. If they’re born a few weeks early, they’ll usually have a lot more. And if baby is born late, the vernix might already be gone.

Benefits of vernix caseosa

Although vernix caseosa’s main purpose is to protect baby’s skin while they’re in the womb, it also has several other benefits for baby – before, during, and after birth:

  • Lubricates baby, so they pass through the birth canal with less friction.
  • Acts as a natural moisturizer, both before and after birth.
        • It keeps baby's skin from drying out and cracking.
        • This is one reason why babies have such soft, smooth skin!
  • Protects a newborn from infections shortly after birth:
      • It acts as a natural barrier to keep bacteria from making contact with the skin.
      • It also has anti-microbial, anti-inflammatory, and antioxidant properties.
    • Helps baby regulate their body temperature once they’ve left the womb.
      • Temperature regulation can take a while – that’s why newborn babies are wrapped in blankets right away – but vernix helps speed up the process.

    When to clean off the vernix caseosa?

    Although you might see the vernix and think that baby needs a bath, don’t be tempted to have it cleaned off right away. Instead, it’s best to wait at least a day before baby gets their first sponge bath, so baby can benefit from the vernix for a longer period.

    According to the World Health Organization (WHO) recommendation, “Bathing should be delayed until 24 hours after birth. If this is not possible due to cultural reasons, bathing should be delayed for at least six hours.”

    One reason the WHO recommends this is to keep the vernix intact for a longer period. In fact, the WHO also advises that the vernix shouldn’t be wiped off right after birth.

    Instead, let baby’s skin absorb the vernix on its own, like you would with any moisturizer (after all, the vernix is nature’s moisturizing lotion!)

    • Baby’s skin will usually absorb the vernix between 24 and 48 hours after birth.
    • You can also help the process by gently rubbing the vernix into baby’s skin over those two days, like you would with any moisturizer.

    An added bonus of not bathing baby immediately is that baby and mother can begin skin-to-skin contact right away, and enjoy more bonding time in the crucial first hours after baby is born. This immediate contact is especially vital if you’re planning on breastfeeding.

    Nowadays, most hospitals follow the WHO’s recommendation on bathing, and wait at least 24 hours before bathing babies.

    • Of course, it’s still best to note your preference about when to bathe baby – and when to start skin-to skin contact – on your birth plan.
    • You can also ask a nurse to gently wipe away blood and amniotic fluid from baby, while leaving the vernix on the skin..

    Learn more about why you should delay baby's first bath from registered nurse Samantha of The Maternity Mentor:

    As for when exactly to time the bath, after those first 24 hours? That’s up to you, as there’s no recommendation on the latest time the first bath should happen.

    Keep in mind that most (if not all) of the vernix should be gone within 1-2 days. And the majority of moms plan baby’s first bath within a week after birth. No need to rush – choose what’s best for you and your little one.

    Are there any reasons to get rid of the vernix earlier?

    Although leaving the vernix on the skin is the best choice for most babies, some babies will still need an immediate bath to reduce their risk of other complications:

      • Babies affected by a bacterial infection of the amniotic sac, to reduce the risk of infection complications
      • Babies born with meconium staining, to reduce the risk of infection
      • HIV-negative babies with HIV-positive moms, to reduce the risk of transmission

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    All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

    These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.