Jaundice

What newborn jaundice is, and its signs

Jaundice is a yellow tint to a baby's skin and the whites of their eyes, caused by a buildup of bilirubin, a yellow pigment made when the body breaks down old red blood cells. It is extremely common: most full-term newborns develop at least some, and the rate is even higher in babies born preterm, because a newborn's liver is still maturing and clears bilirubin slowly while extra red blood cells break down quickly in the first days. The first sign is usually yellowing of the face and the whites of the eyes that spreads downward to the chest, belly, and legs as levels rise, generally clearing in reverse order as it improves. It typically appears around day 2 to day 4 and peaks somewhere between day 3 and day 5. Jaundice can be harder to see in babies with darker skin tones, so checking the whites of the eyes, gums, and inside of the lips in good natural light helps. In most cases this is normal physiologic jaundice that fades on its own with no lasting harm; the eye and skin check is imperfect, so the only reliable way to know a baby's actual level is a skin (transcutaneous) or blood test ordered by their provider.

What causes it and what raises the risk

Common, usually harmless causes include normal physiologic jaundice and feeding-related patterns. Breastfeeding-associated jaundice can occur in the first week when a baby is not yet getting enough milk, which slows clearance of bilirubin; the answer is usually more frequent, more effective feeding rather than stopping breastfeeding. A separate, generally benign pattern called breast-milk jaundice can linger for several weeks. Less common but more significant causes include a blood-type mismatch between parent and baby (for example, Rh or ABO incompatibility), bruising from birth, infection, prematurity, or inherited conditions like G6PD deficiency. Factors that raise the chance of a high level include being born before 38 weeks, a sibling who needed jaundice treatment, jaundice appearing in the first 24 hours of life, and feeding that is not yet well established. Your baby's provider weighs these factors alongside the measured level rather than relying on appearance alone.

How it is monitored and treated

Most jaundice needs nothing more than watchful monitoring and good feeding. Frequent feeding, roughly 8 to 12 times a day for breastfed newborns, helps a baby pass bilirubin out in their stools and stay well hydrated. Before going home, babies are typically checked with a bilirubin measurement, and many are seen again within a day or two of discharge to recheck, especially when discharged early. When a level crosses the treatment threshold for a baby's age in hours and risk profile, the standard treatment is phototherapy, special blue-spectrum lights that help the body change bilirubin into a form it can clear more easily; it is safe and widely used, and most babies recover fully within a day or two. In uncommon, more severe cases, providers may use additional measures. These thresholds are specific to each baby and change hour by hour in the first days, so treatment decisions belong with the care team, not a home judgment call. Sunlight through a window is not a safe or reliable treatment. The reason jaundice gets so much attention is not that it is usually dangerous, but that the rare high level is preventable harm when caught early, so keep newborn appointments and that early recheck visit.

When to call the doctor, and the bottom line

Call your pediatrician or provider promptly if your baby looks more yellow rather than less, if the yellow color spreads to the belly, arms, or legs, if the whites of the eyes look yellow, or if jaundice lasts beyond about 2 weeks. Also call if your baby is feeding poorly, having fewer wet or dirty diapers, seems very sleepy and hard to wake for feeds, or is losing weight. Pale, chalky, or clay-colored stools together with dark urine in a jaundiced baby is another reason to call promptly, since it can point to a liver problem that needs evaluation. Seek emergency care right away (call 911 or go to the ER) if a jaundiced baby is extremely difficult to wake, limp or floppy, arching the neck or body backward, has a high-pitched or inconsolable cry, will not feed, develops a fever, or has stiffening or jerking movements; these can be signs that bilirubin is dangerously high and affecting the brain, which is rare but a medical emergency. The bottom line: for most babies jaundice is a normal, passing part of the first week or two that resolves with good feeding and routine monitoring, so feed frequently, watch the trend of the yellow color along with your baby's alertness and feeding, and call with any concern. This page is general education and not a substitute for medical advice; your pediatrician or provider knows your baby's exact bilirubin numbers, age in hours, and risk factors, and is the right person to guide any decision.