When will my baby start to grow hair

Fetal development: Your baby’s hair
By Kathleen Scogna | animated_fact_check Medically reviewed by Chandani DeZure, M.D., FAAP, pediatric hospitalist | January 18, 2021

Your baby will start to sprout fine body hair called lanugo at around 22 weeks of pregnancy, although this typically falls out within the first few weeks after your baby is born. Meanwhile, the hair on your baby’s head will also become visible around this time. Some babies grow a lot of hair, others have barely any when they’re born. Your baby’s hair color and texture may change during the first months of life.

Will your baby have a head like a fuzzy peach? A fluffy mane that sticks straight up? Swirls of curls? Whatever your baby’s hair looks like at birth, it’s likely to change in the first year of life.

Hair on your baby’s body
Hair follicles start to form deep in your baby’s skin by 14 weeks of pregnancy. Around 20 weeks, fine downy hair starts to sprout from these follicles on the eyebrows, upper lip, and chin. By 22 weeks, hair is also visible on the back, shoulders, ears, and forehead. Called lanugo, this fine hair helps to hold the vernix (a greasy substance that protects your baby’s skin against constant exposure to amniotic fluid) – in place.

Lanugo covers the entire body, and most of it is usually lost before birth. (Some premature babies are covered with lots of lanugo because they’re born before this fine hair is normally shed.) The lanugo a baby is born with typically falls out within the first few weeks of life, though it can persist for longer in some babies. Lanugo may be a completely different color from the hair on your baby’s head. It can also be quite dark, and therefore more noticeable, on babies with darker complexions.

Hair on your baby’s head
The hair follicles on your baby’s scalp form a pattern that will remain for life. And new follicles don’t form after birth, so babies are born with all the hair follicles they’ll ever have.

By 22 weeks, hair is visible on your baby’s head – and may grow like a weed or only slightly by the end of pregnancy. In the weeks after hair starts growing, cells that produce melanin get to work and begin to add color to the strands.

Predicting your baby’s hair color isn’t easy. Experts think that many different genes control the precise amount of melanin that’s made inside each strand of hair, but they don’t know for certain how these genes interact to produce the huge range of possible hair colors. So be prepared for surprises, as your child’s hair color – and texture – can come from any corner of the family tree.

Also, how your baby’s hair looks at birth isn’t necessarily how it’ll look later. Babies often gradually lose their hair within the first 6 months of life and grow new hair in its place (this is more common among Caucasian infants than babies of color). What grows back in may look similar or be a different color or texture entirely.

What you can do during pregnancy
To best support the growth and development of your baby’s hair, eat well for pregnancy and take prenatal vitamins.

Key milestones in the development of your baby’s hair

Weeks pregnant Milestone
14 weeks Hair follicles have begun to form
20 weeks First hairs sprout on eyebrows, upper lip, and chin
22 weeks Hair is visible on the head, and fine, downy lanugo covers the body – especially the shoulders, back, ears, and forehead
23 weeks to birth Melanin starts being produced, adding color to hair
Birth Some lanugo is still present – it will fall out in weeks or months