Newborn Jaundice: Signs, Causes, and When to Call

Newborn jaundice is the yellow tint that can show up on a baby’s skin and eyes in the first days of life, and in most babies it is mild and harmless. It happens because bilirubin, a normal byproduct of red blood cells, builds up faster than a brand-new liver can clear it. I remember staring at my own baby’s face in the window light, wondering whether that glow was normal, so I want to walk you through what to look for and when to pick up the phone.

This guide is general information from parent to parent, not medical advice. Your pediatrician is the right person to check your baby, so please call them with any worry.

Key Takeaways

• Newborn jaundice is common, and HealthyChildren.org (the American Academy of Pediatrics parenting site) says most cases are mild and need no treatment.
• It usually starts on the face and moves down the body as bilirubin rises, so yellow skin on the belly, arms, or legs deserves a call.
• Good feeding helps: Mayo Clinic calls adequate feeding the best preventive step, with 8 to 12 feedings a day for breastfed babies in the first several days.
• Any jaundice in the first 24 hours needs a bilirubin test right away, according to HealthyChildren.org.
• Sunlight is not a safe treatment for newborn jaundice, so never place your baby in a sunny window as a remedy.

What Is Newborn Jaundice?

Jaundice means a yellow color in the skin and the whites of the eyes. In a newborn, it comes from bilirubin, which forms when old red blood cells break down. HealthyChildren.org explains that a baby’s liver needs a few days to become good at clearing it, so levels can climb at first.

Mayo Clinic describes the usual pattern as appearing on the second or third day of life. That is why many families notice it just after coming home, and why follow-up visits in the first week matter so much.

What Are the Signs of Newborn Jaundice?

The main sign is yellowing of the skin and the whites of the eyes. According to HealthyChildren.org, it begins on the face and then spreads to the chest, belly, arms, and legs as bilirubin rises. It can also be harder to see on darker skin, so the whites of the eyes and gums are useful places to look.

Mayo Clinic suggests a simple check: gently press your baby’s forehead or nose, and see whether the skin looks yellow where you pressed. Do this in good light, ideally natural daylight, because dim or yellow lamps can fool your eyes.

Signs that need a prompt call

Call your pediatrician if the yellow color spreads or deepens, or if the belly, arms, or legs look yellow. Also call if your baby is very sleepy, hard to wake, feeds poorly, or is fussier than usual. These are the warning signs both HealthyChildren.org and Mayo Clinic list.

Why Do Some Babies Get Jaundice More Often?

Most babies with jaundice are healthy, but some have a higher chance. Mayo Clinic lists these risk factors: premature birth (before 37 weeks), significant bruising during birth, a different blood type from the mother, and a family history of jaundice or blood conditions.

Feeding trouble is another one. Mayo Clinic notes that jaundice happens in 10% to 30% of babies born to mothers with diabetes, which is one reason your care team may watch certain babies more closely. Having a risk factor does not mean your baby will have a problem; it simply means the team checks more carefully.

How Does Feeding Help With Newborn Jaundice?

Bilirubin leaves the body mostly through stool, so getting plenty of milk helps. Mayo Clinic says adequate feeding is the best preventive step and advises 8 to 12 feedings a day for breastfed babies in the first several days. HealthyChildren.org adds that this frequency also helps build your milk supply.

It is normal for a newborn to take only small amounts at first. HealthyChildren.org notes that a breastfed newborn gets about 1 teaspoon per feeding in the first 24 hours, which is why frequent, short feeds are the goal rather than big ones.

If feeding feels hard, you are not alone. A lactation consultant or your pediatrician can check latch and intake. You may also find our guide on baby reflux and spit-up helpful for understanding what normal feeding looks like in the early weeks.

How Do Doctors Check and Treat Jaundice?

Doctors check bilirubin with a quick skin scan or a small blood test. HealthyChildren.org says all babies should have at least one bilirubin test before leaving the hospital, and a baby who looks jaundiced in the first 24 hours needs a test right away. Mayo Clinic notes that the AAP recommends checking between 24 and 48 hours after birth.

Babies discharged before 48 hours should be seen within 2 days, per HealthyChildren.org. That early visit is not a formality; it catches rising levels before they become a problem.

What treatment looks like

Most jaundice needs no treatment at all. When it does, HealthyChildren.org says the main option is phototherapy, which uses special lights while your baby is undressed, usually in the hospital. Very high levels are treated as an emergency, which is why timely follow-up matters.

The AAP updated its guideline for babies born at 35 weeks or later in September 2022, according to HealthyChildren.org. The update changed how doctors decide when to recheck bilirubin and made thresholds for treatment slightly higher, based on research since 2004.

Is Sunlight a Safe Way to Treat Jaundice?

No. HealthyChildren.org specifically warns that sunlight is not a safe treatment. Direct sun can burn a newborn’s delicate skin and may let bilirubin keep rising unnoticed. If your pediatrician recommends treatment, they will use proper medical phototherapy.

Because newborns also run hot or cold easily, keep them dressed appropriately and out of direct sun. If your baby also feels warm, read our guide on baby fever and when to worry, and call your pediatrician right away for any fever in a newborn.

How Long Does Newborn Jaundice Last?

HealthyChildren.org says jaundice in formula-fed babies usually clears by about 2 weeks, while in breastfed babies it can last about a month or longer. Check with your pediatrician if it lasts beyond 2 weeks in a formula-fed baby or 4 weeks in a breastfed baby.

Keep a simple log of feedings and wet and dirty diapers until your follow-up visits. It gives your pediatrician useful facts, and it helps you feel steadier during those foggy first days. Our umbilical cord care guide pairs well with that routine, since many early checkups cover both.

Practical Tips for the First Weeks

Here is what helped me feel prepared, and it lines up with the guidance above. Look at your baby in daylight each day, feed often, and keep every follow-up appointment even if your baby seems fine.

Also, write down the date and time you first noticed yellowing. When you call the pediatrician, that detail helps them decide how quickly to see your baby. Vaccines and well visits belong in the same plan; see our post on the flu vaccine for babies for what comes later.

For more on the guidance, read the AAP’s page on jaundice in newborns and Mayo Clinic’s overview of infant jaundice.

Summary

Newborn jaundice is common, usually mild, and often gone within a couple of weeks. Watch for yellowing that spreads down the body, feed your baby often, keep follow-up visits, and never use sunlight as a remedy.

Call your pediatrician about yellow skin that spreads, a baby who is hard to wake or feeding poorly, or any jaundice in the first 24 hours. This article is informational only and does not replace advice from your pediatrician.

Frequently Asked Questions

Is newborn jaundice dangerous?

Most newborn jaundice is mild and harmless, according to HealthyChildren.org. Very high bilirubin can be serious, which is why testing and follow-up visits matter. Your pediatrician can tell you where your baby stands.

When does newborn jaundice start?

It usually appears on the second or third day of life, per Mayo Clinic. Jaundice that shows up in the first 24 hours needs a bilirubin test right away.

Can I treat jaundice at home with sunlight?

No. HealthyChildren.org warns that sunlight is not a safe treatment. Ask your pediatrician about proper options such as phototherapy.

Should I keep breastfeeding if my baby has jaundice?

Mayo Clinic recommends continuing to breastfeed and making sure your baby gets enough to eat and stays hydrated, with 8 to 12 feedings a day in the first several days. Ask your pediatrician or a lactation consultant if feeding feels difficult.

How long does jaundice last?

Usually about 2 weeks in formula-fed babies and up to a month or longer in breastfed babies, per HealthyChildren.org. Check with your pediatrician if it lasts longer.