What Is Lanugo in Newborns?

Signs, Symptoms, and Treatments

Newborn baby being given a bath

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If you're not familiar with newborn babies, the sight of a baby covered in hair can be distressing. This special body hair is called lanugo. It appears on preemies and even newborns and is not usually a cause for concern.

Lanugo is important to your baby while they are developing in the womb. It usually goes away before birth, but sometimes it sticks around until a baby is born or even for a few weeks after.

Learn more about why this baby hair is there, how long before it typically goes away, and when it could be a sign of a problem. 

What Is Lanugo?

Lanugo is a soft, fine body hair. It is the first hair that grows out of your baby’s hair follicles while they are still developing in the womb.

The term lanugo comes from the Latin word "lana" which means wool.

It is more common to see this soft, downy hair covering on preemies, but full-term newborns can be born with lanugo, too. While it can be a surprise for parents to see, it's usually normal and not a cause to worry.

Lanugo may look like white or dark hair, or it may not have any pigment or color to it. You might be able to see and feel lanugo on your baby’s back, shoulders, arms, forehead, and cheeks.

The hair can be found anywhere on the body except for the parts that do not have hair follicles—such as the lips, palms of the hands, soles of the feet, sides of the fingers and toes, genitals, and nails. 

Functions

Lanugo appears to have many functions and researchers are continuing to study it and learn about what it does. Experts believe that lanugo has a few important roles.

  • Protects the skin. During pregnancy, your baby is surrounded by fluid in the amniotic sac. Constant exposure to amniotic fluid affects the skin and body temperature.
    • In the womb, a thick, white, greasy substance called vernix caseosa coats your baby's skin and provides a barrier to protect them from the effects of the fluid. Lanugo sticks to the vernix to help it stay in place on the skin. If it did not have the hair to cling to, the vernix could slide off the baby's body.
    • As your baby gets closer to their due date (40 weeks), they will have less lanugo, less vernix, and less protection against the effects of floating in amniotic fluid. You can see these effects if a baby is overdue, as they will often have wrinkly, peeling skin.
  • Regulates the baby’s temperature. Your baby will not start to put on weight and develop a layer of fat to keep them warm until the last few months of pregnancy. The growth of lanugo is believed to help regulate temperature, hold in heat, and keep a baby warm inside the womb.  
  • Stimulates growth and development. Some studies have shown that the movement of lanugo on your baby’s skin might play a role in the release of hormones that reduce stress and stimulate their growth inside the womb.

How Long It Lasts

Lanugo begins to show up on your baby's skin around the fourth or fifth month of your pregnancy (by about 16 to 20 weeks). At approximately 28 weeks, the lanugo is at its most abundant point. After this point, it will start to fall off.

A baby's layer of lanugo usually starts to shed during the seventh or eighth month of pregnancy. There will be less and less of the hair as your baby gets closer to their due date. Many full-term babies lose all their lanugo before they are born, but some do not.

If your child is born with lanugo, it will most likely fall out and go away on its own within a week or two. However, it could last longer and still be normal—especially if your baby is a preemie.

Whether your baby’s lanugo falls out before or after they're born, it will eventually go away. When it does, another type of hair will grow in its place. The new hair is called vellus hair.

Vellus hair is similar to lanugo but thinner and not as noticeable. This hair will cover your baby’s body throughout childhood. Lanugo and vellus hair are not the same as the hair on the head or the hair that develops during puberty (terminal hair).

Variety of Appearance

Lanugo can show up differently in different babies. Depending on the length of your pregnancy it can be absent or abundant. Your family’s genetics will also play a role, making the hair lighter or darker. Here are a few ways lanugo might appear.

Age:

  • Preemies. Babies tend to shed their lanugo the closer they get to being full-term. If a baby is born early (before 37 weeks), they will often have a lot of lanugo and it might take longer to go away.
  • Term infants. A term newborn (37 to 42 weeks) may or may not have visible lanugo. Lanugo is common in up to 30% of full-term newborns. 
  • Overdue (post-term). Babies born after 42 weeks may not have any visible lanugo. 

Genetic factors:

  • Light skin family background. Lanugo might be light or have no color in babies with lighter skin.
  • Dark skin family background. Babies with darker complexions tend to have darker hair and, therefore, darker lanugo. The dark color of the hair makes it more noticeable. 

Treatment

You don't have to do anything special to treat the lanugo on your premature baby or newborn, but the following tips will help you care for your baby's body hair.

  • Be patient. Time is the best treatment for newborn lanugo. Leave your baby’s hair alone and it will eventually disappear. In a few days or weeks, your newborn should lose lanugo—but if it lasts longer, that can still be normal.
  • Don’t use hair removers. Do not wax, shave, or use a body hair remover to get rid of your baby's lanugo. These products are not safe for infants and could harm them.
  • Gentle massage. Massaging the area of skin very gently with mild baby oil might help, but use extreme care to prevent damaging your baby’s skin. Only use products that will not irritate your baby’s skin or eyes.  
  • Talk to the doctor. Your doctor or your baby's pediatrician can answer your questions and reassure you that, more likely than not, the hair is nothing to worry about and will go away on its own.

Common Questions About Lanugo

Here are answers to common questions about lanugo on preemies and newborns.

Do Babies Eat Lanugo?

Babies lose their lanugo while they are still in the womb. It falls off into the amniotic fluid. The babies do drink that fluid—along with whatever is floating in it. Technically, babies do eat their lanugo.

After the baby takes in the lanugo, it will make its way through their system and become part of their first poop (meconium). 

Does It Grow Back? 

It's common to see lanugo on newborns, but once it goes away in the days and weeks after birth, it should not grow back. The development of lanugo after the newborn period can be a sign of several medical conditions.

Lanugo that shows up again later in life is a sign to see your doctor.

  • Extreme Malnourishment. Lanugo can indicate poor nutrition—usually to the point of starvation. This state might be caused by eating disorders such as anorexia or other conditions that cause severe weight loss.
    • Lanugo develops when someone does not have enough body fat to keep them warm. A layer of soft, downy hair protects and insulates the body. Once a person's nutritional status improves, lanugo should go away.
  • Health Problems. Studies have shown that, although rare, lanugo can be a sign of certain health conditions, including cancer, endocrine disorders, or metabolic disorders.
  • Hypertrichosis Lanuginosa. This rare genetic disorder causes excessive growth of lanugo or lanugo-like hair. An infant can be born with the condition or it can develop later in life.
    • The rare disorder is sometimes called "Wolfman" or "Werewolf Syndrome." When it develops later in life, the disorder is sometimes caused by a health condition, eating disorder, or the side effect of a medication. 

A Word From Verywell

If you have never seen a newborn right after birth, you may be surprised when your baby doesn’t look like the newborns you see on TV or in magazines. Even though they are still beautiful, the appearance of a newborn with a pointy head, puffy eyes, and body hair can be shocking.

Don't worry—your baby just needs a little time to recover from birth. A pointy head will round out, puffy eyes will go down, and newborn body hair will fall off.

Lanugo is a natural part of development for babies, but it’s not natural after the newborn stage. If your baby’s lanugo lingers beyond a few months, point it out to your pediatrician.

If lanugo develops on an older child, teenager, or adult, talk to your doctor. It could indicate a serious health problem that needs treatment. 

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