Key takeaways: Jaundice is very common and usually harmless, peaking around days 3 to 5. Your baby’s bilirubin is checked before discharge and a follow-up plan is set. Frequent, effective feeding helps. Call the same day if yellow color spreads, your baby is very sleepy or feeding poorly, or stools are pale.
If your baby’s skin or the whites of the eyes look a little yellow in the first few days, you’re not alone. About 60 percent of term newborns develop visible jaundice in the first week. Most cases are mild and go away on their own. A few babies need treatment, and catching those early is what keeps jaundice safe.
What Causes Newborn Jaundice?
Jaundice is caused by bilirubin, a yellow substance made when the body breaks down old red blood cells. Newborns have more red blood cells than adults, and those cells break down faster. At the same time, a newborn’s liver is still learning to process bilirubin, and their intestines haven’t yet started moving stool through quickly. The result is a temporary buildup of bilirubin in the blood and skin.
This kind of jaundice, called physiologic jaundice, usually:
- Appears after the first 24 hours.
- Peaks around days 3 to 5.
- Fades within 1 to 2 weeks (sometimes longer in breastfed babies).
Types of Jaundice in Breastfed Babies
Two patterns are often confused:
- Suboptimal intake jaundice (sometimes called breastfeeding jaundice) happens in the first week when a baby isn’t getting enough milk. Less milk means fewer stools, and bilirubin is reabsorbed from the gut instead of leaving the body. The fix is more effective feeding, sometimes with supplementation.
- Breast milk jaundice appears after the first week and can last 6 to 12 weeks in a thriving, well-fed baby. It’s thought to be caused by substances in breast milk that slow bilirubin processing. It’s generally harmless, and breastfeeding should continue. Your doctor may still check levels or other causes if it lingers.
Who Is at Higher Risk?
Your baby may need closer monitoring if they:
- Were born before 38 weeks.
- Had jaundice in the first 24 hours of life.
- Have a different blood type from the birthing parent (blood group incompatibility) or a positive antibody test.
- Have bruising or a large swelling on the head from birth (cephalohematoma).
- Have a sibling who needed phototherapy.
- Have G6PD deficiency or another condition that breaks down red blood cells faster.
- Aren’t feeding well or have lost a lot of weight.
From the author
From First Breath to First Birthday is my month-by-month guide to your baby’s first year, written as a NICU and postpartum nurse. My book starts in the first hours after birth and walks you through every newborn check and the weeks that follow.
How Jaundice Is Checked
Before discharge, your baby’s bilirubin will be measured with a skin meter (transcutaneous bilirubin) or a small blood test. The 2022 AAP guideline asks providers to plot the result based on your baby’s age in hours and risk factors. That determines whether your baby needs treatment, a repeat test, or simply a follow-up visit, usually within 1 to 3 days of discharge.
Looking at skin color alone isn’t reliable for judging bilirubin levels, especially in babies with darker skin. Check the whites of the eyes and the gums, and keep your follow-up appointment even if your baby “looks fine.”
How Jaundice Is Treated
- Feeding: frequent, effective feeding (8 to 12 times a day) helps your baby pass bilirubin in stool. If your baby isn’t getting enough, your doctor may recommend supplementing with expressed milk, donor milk, or formula.
- Phototherapy: special blue light changes bilirubin in the skin into a form the body can remove more easily. It can be done in the hospital and, in some cases, at home with a light blanket. It’s safe and effective. Your baby wears eye protection and as little clothing as possible, and you can usually take breaks to feed.
- Exchange transfusion: very rarely, when levels are extremely high or rising quickly despite phototherapy, a baby may need a blood exchange in a NICU.
Sunlight is not a safe treatment. Placing a baby in a sunny window isn’t reliable and risks sunburn and overheating. The AAP does not recommend it.
Why Follow-Up Matters
Very high bilirubin levels can cross into the brain and cause a serious type of brain injury called kernicterus, which can lead to hearing loss, cerebral palsy, and other lasting problems. Kernicterus is rare today because of screening and treatment, and it’s preventable. That’s why follow-up checks are so important in the first days after discharge.
Call your baby’s doctor the same day if:
- Yellow color is spreading to the belly, arms, or legs, or your baby looks more yellow.
- Your baby is very sleepy, hard to wake, or not feeding well.
- Your baby has fewer wet or dirty diapers than expected.
- Stools are pale, white, or clay-colored, or urine is dark (these can signal a liver problem).
- Jaundice lasts more than 2 weeks (or 3 weeks in a breastfed baby).
Seek emergency care if your baby: is very difficult to wake, is limp or floppy, has a high-pitched cry, arches the back and neck, or won’t feed.
The Bottom Line
Jaundice is common, usually mild, and very treatable. Feed often, keep every follow-up appointment, and call right away if your baby looks more yellow, is sleepy, or isn’t feeding well.
My book From First Breath to First Birthday walks you through jaundice, feeding, and every newborn check in detail.
Related Articles
- Prolonged Jaundice: When Yellow Skin Lasts Beyond Two Weeks
- Going Home Early: What to Watch for if You Leave Before 48 Hours
- Your Baby’s First Pediatrician Visit at 3 to 5 Days: What to Bring and Ask
- Late Preterm Babies: Why Babies Born at 34 to 36 Weeks Need Extra Care
Sources
- Kemper AR, Newman TB, Slaughter JL, et al. Clinical practice guideline revision: management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2022;150(3):e2022058859.
- Flaherman VJ, Maisels MJ; Academy of Breastfeeding Medicine. ABM Clinical Protocol #22: Guidelines for management of jaundice in the breastfeeding infant 35 weeks or more of gestation, revised 2017. Breastfeed Med. 2017;12(5):250-257.
- Bhutani VK, Johnson LH, Keren R. Diagnosis and management of hyperbilirubinemia in the term neonate: for a safer first week. Pediatr Clin North Am. 2004;51(4):843-861.
- Keren R, Tremont K, Luan X, Cnaan A. Visual assessment of jaundice in term and late preterm infants. Arch Dis Child Fetal Neonatal Ed. 2009;94(5):F317-F322.
- Centers for Disease Control and Prevention. Jaundice and kernicterus: facts. https://www.cdc.gov/jaundice
- Harpavat S, Garcia-Prats JA, Anaya C, et al. Diagnostic yield of newborn screening for biliary atresia using direct or conjugated bilirubin measurements. JAMA. 2020;323(12):1141-1150.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
