Your baby's skin, hair, and fingernails all start to form during the first trimester of pregnancy, and continue to develop even after birth. Your baby's true skin color may not be visible until they're around 6 months old!
Your baby's soft, smooth skin is the largest organ in their body. During pregnancy, your baby's skin develops while in the amniotic fluid inside your uterus. This is a warm and cozy home for them.
After birth, your baby's skin undergoes subtle changes that help them adjust to the new world around them. A baby develops skin in the womb very early on, and their hair and nails aren't far behind.
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Read on to learn more about baby skin, hair, and nails – and the best ways to encourage their healthy development during pregnancy.
Baby skin development in the womb
At just 5 weeks pregnant, your tiny embryo is made of three layers. The top layer, called the ectoderm, will develop into baby's outermost layer of skin (the epidermis), their central and peripheral nervous system, eyes, and inner ears.
At first, your baby's skin is so thin and translucent that you can see the blood vessels beneath it. During week 13, baby skin is still thin, but by week 16, it's getting thicker. When you're 18 weeks pregnant, the layers of the skin have finished forming. As your baby gets closer to birth, the skin becomes thicker and more opaque – but it's still delicate and very soft.
By about 19 weeks of pregnancy, your baby has developed vernix, a greasy, cheese-like coating the covers their skin. It protects baby's delicate skin from constant exposure to amniotic fluid. Without the vernix, your baby would be exposed to wastes and other irritants that could cause abrasions, chapping, and hardening of the skin.
Many babies are born with patches of vernix clinging to their skin. Rather than washing it off right away, most experts now recommend waiting until 24 hours after birth to bathe a baby, giving the vernix time to absorb into the skin and provide additional protection against germs, water loss, and temperature changes. If waiting for 24 hours isn't feasible, experts suggest waiting at least six hours.
Ridges form in the palms of baby's hands and the soles of their feet in week 23. These ridges will later develop into baby's unique fingerprints and footprints. (Even identical twins or multiples who share the same DNA don't have perfectly matching fingerprints, because factors beyond genetics come into play in fingerprint formation.)
During week 24, baby's skin is wrinkled. It's also translucent and pink or red looking because of visible blood vessels. Once the second trimester ends at 27 weeks, babies continue to gain more fat, which helps their skin look smoother.
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At 35 weeks, baby's skin is becoming smooth like it will be at birth. They're getting chubbier now, too – making them extra cute, just in time to meet you.
When do babies get their skin color?
Beginning at 6 to 8 weeks of pregnancy, the cells that will later produce melanin – the substance that accounts for skin color – first appear in your baby's skin. The more melanin that's produced (a process that's regulated by genes), the darker your baby's skin, eyes, and hair will usually be.
When a baby is born, their skin is a dark red to purple color. As they breathe air, the color changes to red, which typically fades in the first day. A newborn baby's hands and feet might initially appear blue as their circulatory system adjusts to the outside world. Newborns might also have milia – tiny white bumps on the nose, cheeks, chin, and forehead – as well as vernix, lanugo, baby acne, and various birthmarks.
Babies of parents with dark skin may look noticeably lighter than their parents at birth and then get darker skin over time. Melanin production increases, darkening your baby's skin and providing a degree of protection from the sun's ultraviolet rays – a protection that your baby didn't need in the womb. Your baby's permanent skin tone will likely be fully developed around 6 months.
Baby nail development in the womb
Baby nail development in the womb begins during the first trimester. Baby's fingernails form at 12 weeks of pregnancy. And then at 17 weeks, baby's toenails begin developing.
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During your third trimester, baby's fingernails and toenails have gotten much longer. Baby's fingernails reach their fingertips at 34 weeks, and baby's toenails are right behind, reaching the tip of their toes at 38 weeks. (Get those infant nail clippers ready!)
Baby hair development in the womb
Hair bud formation happens during the eighth week of pregnancy, and hair follicles appear by week 10.
During the second trimester, at 15 weeks into pregnancy, hair follicles on your baby's scalp start forming the pattern you'll see on their sweet little head at birth – whether it's simply peach fuzz or a full head of hair. Between 16 to 20 weeks pregnant, hair follicles have formed in the skin on various parts of your baby's body, including the eyebrows, back, and shoulders. Some of the fine hair that grows here – called lanugo – helps hold the vernix on the skin and will fall out during the first several weeks of life.
And at 21 weeks, baby is completely covered with lanugo. Babies shed lanugo before birth at around 33 to 36 weeks, but about one-third of babies are born with it. Premature babies are more likely to have lanugo at birth. If your baby is born with it, it should disappear on its own in time.
By about 22 weeks, your baby's hair and eyebrows are visible. In fact, at 30 weeks pregnant, your baby could already have a good head of hair.
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How to support the development of your baby's skin, hair, and nails
Eating well for pregnancy and taking prenatal vitamins help support the growth and development of your baby's skin. Vitamin D in particular is essential for healthy skin. Pregnant women can drink milk fortified with vitamin D and eat fatty fish like salmon once a week. Getting safe exposure to the sun is also helpful. Talk to your healthcare provider to make sure you're eating a balanced diet and taking the recommend amount of vitamins and minerals each day.
Key milestones in your baby's skin
Weeks pregnant | Milestone |
5 weeks | Skin starts to form. |
18 weeks | Layers of skin have finished forming. |
19 weeks | Vernix coats the skin. |
21 weeks | Lanugo completely covers baby's body. |
23 weeks | Fingerprints and footprints start to form. |
24 weeks | Baby's skin is wrinkled, translucent, and pink to red in color. |
35 weeks | Skin is becoming smooth. |
After birth | Melanin production increases, darkening the skin. |
Learn more:
- Benefits of skin-to-skin contact with your newborn
- 5 baby skin issues to expect in the first year