Jaundice in newborns

If your baby’s skin or the whites of their eyes take on a yellow tinge in the first days, that’s jaundice — and it’s extremely common, affecting a large proportion of newborns. In most cases it’s mild and harmless and clears on its own. Understanding it helps you know when it’s the ordinary kind and when to get it checked.

Why it happens. Jaundice is caused by a build-up of bilirubin, a yellow substance made when the body breaks down old red blood cells. Newborns make a lot of it and their livers are still getting up to speed at clearing it, so it can accumulate and tint the skin. It’s a very normal part of the newborn adjustment for many babies.

When it usually appears. Typical “physiological” jaundice tends to show from around day two or three, peaks over the next few days, and fades by around two weeks. It often starts on the face and can spread downwards as levels rise. Your midwife will be keeping an eye on it during their checks.

How it’s checked. Your midwife or doctor assesses jaundice by looking at your baby (sometimes pressing gently on the skin) and, if needed, measuring the bilirubin level with a light meter on the skin or a small blood test. This tells them whether the level is in a safe range or needs treatment.

How it’s treated if needed. Most jaundice needs no treatment beyond good feeding, which helps your baby clear bilirubin through their nappies — so frequent feeds matter. If levels are high, the usual treatment is phototherapy: your baby rests under special blue lights (sometimes on a light blanket) that help break down the bilirubin. It’s safe, common, and usually short. Very high levels are rare but treated urgently.

When jaundice needs prompt attention. Some jaundice isn’t the ordinary kind. Contact your midwife, doctor or hospital straight away if: jaundice appears in the first 24 hours of life; it looks deep, spreads to the arms and legs, or keeps worsening; your baby is very sleepy, hard to wake, floppy, or feeding poorly; or their poos are pale and wee is dark. These need checking without delay.

Jaundice that lingers. Jaundice lasting beyond two weeks (or three weeks in premature babies) — “prolonged jaundice” — should be reviewed even if your baby seems well, as occasionally it points to something that needs treatment. Mention it to your child health nurse or GP; a simple check sorts out whether anything more is needed.

Feeding is your best tool. Whether breast or bottle, feeding your baby often and well is the single most helpful thing you can do for ordinary jaundice, because it helps move bilirubin out. If feeding is tricky or your baby is too sleepy to feed properly, ask for help early rather than waiting.

Some babies are more prone to it. Jaundice is more likely, or can be more pronounced, in babies born a little early (premature or “near-term”), babies who are bruised from the birth, those whose feeding is slow to get going, and where there’s a blood-group difference between you and your baby (for example if you’re Rh negative or have a different blood type). Some babies also develop mild, longer-lasting “breastmilk jaundice”, which is usually harmless. Your midwife takes these factors into account, which is part of why the early checks and good feeding support matter — none of it means you’ve done anything wrong.

Jaundice sounds worrying, but for most babies it’s a mild, passing part of the first couple of weeks that resolves with time and good feeding. Keep feeds frequent, let your midwife monitor it, and use the “straight away” signs above as your guide — when in doubt, always ring and ask — your midwife and child health nurse would far rather check a baby who turns out to be fine than have you sit at home worrying.