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What Is Lanugo? Why Is My Newborn Baby Covered in Hair?

Robin is a former third-grade teacher, has a Masters in Education, and has three children of her own.

What Is the Hair on the Body of My Newborn?

Sometimes babies are born with hair on their bodies—more hair than you would imagine. Why is that? Why are some babies born with "hairy bodies"? If your child is born with more hair than you would expect on a newborn, don't worry! This is actually very normal and not anything to worry about. Let's find out why.

Photo of Infant With Lanugo

Photo of Infant With Lanugo

What Is Lanugo?

The soft, downy hair that can be seen covering the bodies of many babies is called lanugo. In fact, in Latin, lanugo means down. Most unborn babies shed the lanugo hair just before birth, but about 30% of full-term babies are born with lanugo (which usually falls off shortly after birth).

The Connection Between Lanugo and Premature Birth

Premature babies are more likely to have lanugo than those born at or near full term. A premature birth is one that occurs before the 37th week of gestation. Lanugo usually falls off during the last eight weeks of pregnancy but is often present at birth, especially if the baby is born early.

Is Lanugo a Birth Defect?

No, lanugo is not a birth defect. Lanugo hair is a natural and necessary part of fetal development and helps the baby in many ways. About a third of all babies are born with some lanugo, which means that hairy babies are common and completely normal.

Where Did the Hair Come From?

Between 16 to 20 weeks of gestation, unborn babies will grow lanugo hair all over their bodies (except in places without hair follicles, like the lips, palms, soles, etc.). The fetal hair follicles produce this first hair. Babies who are born at or near their due dates have usually shed most of this hair inside the womb, usually around the 28th or 32nd week of gestation.

Why Is My Baby Covered in Hair?

Lanugo isn't entirely understood, but it is believed to serve at least three purposes: to protect the skin, help keep the baby warm, and stimulate growth.

  • Lanugo to maintain temperature. Lanugo is a downy hair that helps insulate and regulate temperature. In early gestation, babies don't have a lot of fat stores, so the lanugo helps them maintain an appropriate body temperature.
  • Lanugo to protect skin. Vernix is a waxy, cheese-like substance that covers the fetus and protects it from amniotic fluid inside the womb. Lanugo helps the vernix stick to the skin.
  • Lanugo to aid growth. Experts don't entirely understand the role lanugo plays in a baby's growth, but they continue to study lanugo and how it is affected by hormones. They have noted that when lanugo is touched or moved, the hair vibrates and stimulates a baby’s sensory receptors, spurring the baby’s growth. When the hair falls off, the stimulation stops and the baby’s growth slows.

Why Does My Baby Have a Hairy Forehead (or Shoulders or Back)?

The downy, colorless lanugo hair can be found anywhere on a baby's body—except places without hair follicles like the palms, lips, and soles of the feet. Although it may be unexpected to see hair on a baby's forehead (or shoulders!), its appearance does not mean your baby will always be hairy there.

How Long Will the Lanugo Last?

Don't worry, the downy lanugo hair usually falls out after the newborn stage. If your baby's lanugo lasts beyond a few months, check with your pediatrician.

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What Is the Cure or Treatment for Lanugo?

Lanugo is a normal occurrence in newborns. It is not "treated" or "cured" because it is not considered a problem. It usually falls out within weeks after birth.

Where Does the Lanugo Hair Go?

At 36 to 40 weeks' gestation, the lanugo hair is replaced by vellus hair. This hair is fine and without pigment. It is present on children and adults, and hormones do not play a part in its growth.

Interestingly, it is thought that the baby, while in the womb, ingests the lanugo they have shed, and it becomes part of the first bowel movement, or meconium.

Bottom line: If your baby is born with lanugo, there is absolutely no cause for concern. This hair eventually falls out, and your baby will no longer be "hairy."

Further Research

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Thoughts, Comments, Questions?

Elena@LessIsHealthy on September 05, 2011:

Interesting hub, rated up.

Emma from Houston TX on March 17, 2011:

Very superb piece of information and lecture you really shared with us.Honestly,am already falling in love with the kind of selective piece of article you always share in here.Keeping on going,bravo.

siva@myhealthbowl on January 25, 2011:

i have seen the best meaning for the lanugo hair.congradulates.

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