When Babies Start Growing Hair, Skin and Nails

In the weeks after conception, your baby starts out as an embryo made up of three distinct layers: the endoderm, mesoderm and ectoderm, all of which form at just 3 weeks of pregnancy. It’s in the last of these “derms”  — the ectoderm  — where the vast majority of skin, hair and nails develop.

Wondering how your baby’s hair and skin grows, what it will look like at birth and how it will likely change in the months to years to come? Read on to learn all about baby’s hair, skin and nail development during pregnancy and beyond.

When do babies grow hair?

Around week 14 or week 15 of pregnancy, teeny-tiny baby hairs start to poke through the skin at a slight angle, setting the stage for your baby’s hairline to appear very soon. Eyelashes and eyebrows are looking pretty good too by around week 22.

Throughout pregnancy, your baby's hair will actually go through two cycles of shedding and regrowth. A precise pattern eventually emerges, with all follicles evenly spaced. In fact, not a single follicle forms after birth. 

As your baby’s brain grows, the delicate skin on her scalp stretches to accommodate it, which results in the parietal hair whorl — that clockwise (or counterclockwise) twirl of hair on the back of your head.

Just because all (hair) systems are a go before your baby’s born doesn’t mean that your little one will actually be born with much (or any) hair. Some babies are born with a mop top, while others come out looking like a cue ball.

The amount of hair you can expect on your newborn’s head is up to genetics, which actually makes it relatively predictable. Darker complexions have slower grow-and-shed cycles, which mean a thicker head of hair at birth. 

Another clue: If you experience a significant amount of heartburn during pregnancy, there really is a slightly better chance your baby-to-be will have a good head of hair. Researchers have found evidence supporting this old wives’ tale, noting there’s likely a biologic mechanism involving pregnancy hormones that both relaxes the esophageal sphincter (causing heartburn) and regulates fetal hair growth.

Once your newborn’s first strands sprout in, don’t get too attached to what you see. When your baby is 8 to 12 weeks old, her hair will go through one more phase of development, which often results in hair loss. 

For a little while, at least, your baby’s thick head of hair may very well go bald. Hair loss may also occur so gradually that you don’t even notice it’s happening.

When your baby will get “terminal hair” (or the hair she’ll have as a grown-up) can vary wildly. A more permanent set of hair may grow in around the same time her baby hair is falling out — or your baby may remain more or less hairless until she’s 2 years old. 

What color hair will my baby have?

If you could snap a photo of your baby in utero, you wouldn’t see black curls or blond wisps just yet. Hair is pigment-free and bright white during pregnancy. In fact, all babies — no matter their ethnicity — sport the same thin, silky and often lightly-colored hair at birth, called vellus. 

Ultimately, your baby’s appearance after birth — including her hair color — depends on genetics (i.e. the DNA that’s inherited from each biological parent). Brown and black hair genes are dominant over blond and red hair genes. Other inherited genes that control how much pigment you have in your hair also play a role.

Generally speaking, if one parent is blond and the other is a brunette, a baby has about a 50 percent chance of being blond if the brunette parent has a recessive blond gene. It’s also possible for two brunettes to give birth to a blond or redhead if they both have and pass on a recessive blond or red-hair gene.

No matter what genetics have in the cards for your little one, you should be prepared for her hair texture and color to change after birth, as those newborn locks fall out and a more permanent set of hair replaces them. In other words, your blondie could turn into a brunette.

In fact, you should expect quite a bit of variation in your little one’s hair color within her first few years of life. 

What is lanugo?

Lanugo is a downy coating of hair that covers a baby’s body in utero to help keep her warm. By week 14 of pregnancy, your baby will have a furry coat of it.

But as fat accumulates on your baby’s body and takes over the job of keeping her warm, lanugo begins to shed at around week 30 of pregnancy. It's possible she'll still have some lanugo — usually across the shoulders, down the forehead or on the tops of ears — at birth, but it'll usually fall away in the first few weeks. 

When do babies develop skin?

Skin is the body’s largest organ, which is perhaps why it shouldn’t come as a surprise that your baby’s epidermis (i.e. skin) starts to emerge early, between weeks 5 and 8 of pregnancy. At this point, it consists of two layers: basal cells (the inner layer of cells) and periderm cells (the outer layer of cells). 

When you’re around 9 or 10 weeks pregnant, a new intermediate cell layer begins developing. It's right in between the basal and periderm layers, and it’s where your little one’s hair follicles emerge. 

Over the coming weeks, skin development continues so that by month 4, all of baby's skin layers have formed. 

Yet up until the very last weeks of pregnancy, your baby’s skin will actually look transparent since she has so little body fat. At around 32 weeks, as she steadily grows bigger, your transparent baby in the womb takes a turn for the opaque. 

What is vernix caseosa?

Come week 19, your baby-to-be’s still-transparent and fragile skin is covered with vernix caseosa (which roughly translates to “cheese varnish” in Latin). This greasy, white layer is made up of shed skin cells and sebaceous secretions, like oil. 

It protects your baby’s skin from amniotic fluid. Without it, your little one would look even more wrinkled at birth than she often already does after her 9-month-long acidic bath.

By about week 34, baby-to-be’s protective vernix thickens up, only to be (mostly) shed a couple of weeks later. At that point, it combines with baby’s departing lanugo in the amniotic fluid. Your baby actually swallows the mix, and it becomes meconium (or your baby's first poop).

What color skin will my baby have?

When your baby is finally born, she’ll have a reddish-purple complexion no matter either parent’s skin color. 

Baby’s complexion will slowly change to its permanent tone once her circulatory system adjusts to out-of-womb life — a process that can take up to six months for some babies.

When do babies develop fingernails and toenails?

Your baby’s fingernail and toenail beds begin to form at week 11 of pregnancy with the nails themselves starting to grow at week 12. 

By about 34 weeks of pregnancy, give or take, your baby’s itty-bitty finger- and toenails will be just about ready for their first eventual postpartum mani and pedi.

Your baby’s skin, hair and nails begin developing early in pregnancy and go through lots of changes before birth. Even after she arrives, it’s normal to see an evolution in your baby’s hair and even her skin color that may continue in the weeks (and sometimes years) to come.