What is happening

The American Academy of Pediatrics gives the answer in one sentence, and it covers nearly every version of the question: "Babies are born with hair, but the amount, texture, and color vary from one newborn to another. Most, if not all, 'baby hair' falls out during the first six months and is replaced by mature hair."

The AAP adds the part that catches parents out later: "The color and texture of the mature hair may be different from the hair the baby was born with." A dark-haired newborn can grow back fair. A baby born nearly bald can grow thick hair. Neither is predictable from the first head of hair.

So newborn hair loss is not loss in the way an adult experiences it. It is a scheduled handover between two different kinds of hair.

The bald patch at the back

The commonest pattern is thinning at the back and sides — the parts in contact with the mattress. Newborns sleep on their backs for every sleep, which is the single most important thing you do to reduce the risk of sudden infant death syndrome, and a consequence is friction on the back of the head at exactly the age when the first hair is due to shed anyway.

The response is not to change how your baby sleeps. It is the same advice the NHS gives for avoiding flat spots on the head: plenty of supervised tummy time while your baby is awake, changing the position of toys so they turn their head both ways, varying the side you feed and carry from, and not leaving your baby lying in a pram or sitting in a car seat for long once you have arrived somewhere. Those reduce the hours of pressure on one spot without touching the safe sleep rule.

Lanugo — the hair that is not on the head

Plenty of newborns have soft, fine hair across the shoulders, back, ears and forehead. The AAP describes it: "As you examine your baby's shoulders and back, you may notice fine hair, called lanugo. This hair is produced toward the end of pregnancy; however, it's usually shed before birth or soon thereafter."

Timing depends on when your baby was born: "If your baby was born before her due date, she is more likely to still have this hair, and it may take a couple of weeks to disappear." Premature babies keep it longest. Overdue babies often have none at all, having shed it in the womb.

Nothing is done about lanugo. It is not shaved, scrubbed or oiled off. It goes.

What actually helps

Almost nothing, and the guidance is unusually consistent about what to avoid.

No shampoo for most young babies. The HSE says plainly: "You do not need to use shampoo in most young babies' hair. Use a baby comb or brush to gently remove flakes of skin from your baby's hair."
Plain water for the first weeks. The NHS advises bathing your baby with plain water only for at least the first month, and not adding cleansers to the bath water or using skin lotions or medicated wipes. The HSE gives four weeks or so for the same reason: fragrances and chemicals in baby products can irritate newborn skin.
Brushing is fine, including over the soft spot. Both the NHS and the AAP say the fontanelles are covered by a tough protective membrane and you need not be afraid to touch them gently.
Nothing on the scalp to encourage growth. No oil, serum or supplement has any published evidence behind it for newborn hair, and no health body recommends one.
Do not shave the head to make hair grow back thicker. There is no published evidence supporting this, and newborn scalp skin is thin and easily damaged.

What about cradle cap

Flaking, yellowish scales on the scalp often turn up at the same time as the shedding, and they are a separate thing. The HSE's guidance is that cradle cap is common and usually goes away on its own, that from around six weeks old a mild baby shampoo helps reduce the build-up, and that gently brushing the hair helps remove scales. To loosen stubborn scales the HSE suggests a small amount of natural baby oil left on overnight and shampooed out in the morning, and asking a pharmacist or public health nurse if that does not work. Hair sometimes comes away with the scale — it regrows.

When hair loss is worth mentioning

Hair loss on its own, in a well baby, is not a symptom. What changes that is what comes with it. The NHS's general instruction on newborn skin and spots is the right frame: these things are common, but if you also notice a change in your baby's behaviour — not feeding well, very sleepy, very irritable — tell your midwife or GP immediately.

Ask for a look if you see a single patch of complete baldness with scaly, red or inflamed skin, a sore or crusted area, hair loss that starts after six months rather than tailing off, or a baby who is not gaining weight alongside it.

When to call

Speak to your midwife, health visitor, public health nurse or GP if: there is a defined bald patch with red, scaly or broken skin; the scalp is sore, weeping or crusted; hair loss is still progressing after six months; or your baby is also feeding poorly or not gaining weight.

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) if your baby: looks pale, ashen, mottled or blue; is unresponsive or unrousable; has a weak, abnormally high-pitched or continuous cry; is grunting, breathing over 60 breaths a minute or drawing their chest in; has a temperature of 38C (100.4F) or above or below 36C (96.8F); has a bulging fontanelle, neck stiffness or a seizure; or has a rash that does not fade under a pressed glass. Those are NICE's red flags for serious illness in young babies, from its postnatal care guideline NG194, and they are the list worth knowing regardless of what brought you here.

What to let go of

Newborn hair loss says nothing about nutrition, vitamins, your diet if you are breastfeeding, or what your child's hair will be like at five. The AAP's timescale — most or all of it gone within six months, replaced by mature hair that may look completely different — is the whole story, and it needs no intervention from you at any point.

Newborn Hair Loss