Newborn jaundice

A yellow tinge to the skin and to the whites of the eyes appears in most babies during their first days and usually clears on its own: a newborn's liver cannot yet keep up with bilirubin, the yellow pigment left behind when red blood cells break down. What matters is not the colour itself but three things — when it appeared, how quickly it is spreading, and what colour the baby's urine and stools are. Those are what separate ordinary jaundice from the kind that needs treatment or further investigation.

What you can see

The yellow starts on the face and in the whites of the eyes and, as bilirubin rises, moves down to the chest, the tummy, the thighs and the legs. The further down it reaches, the higher the pigment level tends to be.

Look in daylight by a window: filament bulbs add yellow and cold LED light hides it. Press gently on the forehead or the tip of the nose and lift your finger — for a moment the blanched patch shows the true shade. In babies with brown or black skin the colour is misleading, so it is more reliable to check the whites of the eyes, the gums, the roof of the mouth, the palms and the soles.

Check the nappy too. A newborn's urine is almost colourless, so a dark yellow stain is worth a doctor's opinion. Stools range from mustard to green or orange; white, grey or pale beige stools are a warning sign.

Why there is so much bilirubin in the first days

Before birth a baby takes oxygen through the placenta, and this is offset by a large number of red blood cells carrying foetal haemoglobin. After the first breath that surplus is no longer needed, some of the cells break down quickly, and each one leaves a portion of bilirubin behind.

Dealing with it is the liver's job: it attaches a soluble tag to bilirubin so the pigment can pass with bile into the bowel and leave the body in the stools. In a newborn the enzyme responsible works at half speed for the first few days, and some of the processed pigment is reabsorbed from the bowel. More bilirubin is made than in an adult and it leaves more slowly. By about two weeks the enzyme is up to speed, red cell breakdown slows, and the jaundice fades by itself.

Feeding is therefore part of the answer: milk gets the bowel moving, and every dirty nappy takes bilirubin with it. Feed often, without long gaps overnight, and wake a sleepy baby who is missing feeds. Topping up with water or glucose solution does not help — it removes no bilirubin, displaces milk and slows recovery down.

The timings that separate ordinary from worrying

When jaundice appears tells you more than how bright the colour is.

• The first 24 hours of life. Jaundice visible on day one is never the ordinary kind. It usually means red blood cells are breaking down faster than they should, and the baby needs a blood level checked that same day.
• Days two to four. The usual pattern: the colour builds up, peaks around day three to five and then fades.
• Longer than two weeks in a baby born at term, or longer than three in a premature baby. Not yet a problem, but a reason to look into the jaundice rather than keep waiting.
• Coming back. Jaundice that had almost gone and then returns needs to be reviewed.

The earlier a baby was born, the less mature the liver and the lower the bilirubin level at which treatment starts. Babies who have lost a lot of weight, who have extensive bruising after delivery or an infection, and those whose older brother or sister needed light treatment as a baby, are also watched more closely.

Jaundice and breastfeeding

Breastfed babies get jaundiced more often and stay yellow longer, sometimes for six to eight weeks. The reason is not fully understood: certain substances in breast milk probably slow the processing of bilirubin and increase how much is reabsorbed from the bowel. In itself this is harmless — the baby feeds well, gains weight and develops normally.

It is easily confused with a different, earlier situation: in the first days there is not much milk yet, the baby underfeeds, passes few stools, bilirubin stays put and the yellow deepens. Here the problem is the amount of milk rather than anything in it, and the answer is to get feeding established, not to stop it.

There is no need to give up breastfeeding because of jaundice. But nor should prolonged yellowing simply be put down to the milk without checking: the same picture can hide causes that are treated quite differently.

What can lie behind it

A small proportion of cases is not about an immature liver but about a specific illness. The commonest are:

• Blood incompatibility between mother and baby, by rhesus factor or by group. Maternal antibodies destroy the baby's red cells, bilirubin climbs fast and the jaundice starts early.
• Inherited red cell disorders: G6PD deficiency, hereditary spherocytosis, sickle cell disease. G6PD deficiency is common in families from the Mediterranean, Africa, the Middle East and South Asia, so it is worth mentioning in advance.
• Infection, from a urine infection to sepsis. Here drowsiness and poor feeding matter far more than the shade of the skin.
• An underactive thyroid. This is looked for when jaundice drags on, especially if the baby is flat, sleeps a lot and feeds badly.
• Pooled blood: a large birth bruise or extensive bruising releases bilirubin as it is reabsorbed. Rarer still are inherited faults in handling bilirubin, such as Crigler-Najjar syndrome.

Biliary atresia deserves a separate mention. In this uncommon condition the bile ducts close off and bile cannot leave the liver. Three signs together give it away: jaundice lasting beyond two weeks, stools drained of colour to white or pale grey, and dark urine. The baby may look well and gain weight normally. Time here is counted in weeks: surgery done within the first two months of life works incomparably better than the same operation later. If a jaundiced baby is passing pale stools, the appointment cannot wait a single day.

How bilirubin is measured

The level is never judged by eye — skin colour misleads parents and doctors alike. Two methods are used.

• A transcutaneous bilirubinometer. Held against the forehead or chest, it estimates the level from the way the skin reflects light. Quick, painless and good enough for screening.
• A blood test, taken from the heel. Used if jaundice appeared on the first day, if the meter reading is high, if the baby is premature or is already being treated.

The figure is not compared with a single normal value. It is plotted on a chart that takes into account the baby's age in hours and the week of pregnancy at which they were born. The same result can be reassuring in a five-day-old term baby and a reason to start treatment at once in a one-day-old premature baby.

If jaundice persists, further tests are added: how much of the bilirubin is conjugated, blood group and antibodies, a full blood count, thyroid function and a urine sample for infection. A rise in conjugated bilirubin, together with pale stools, points to an obstruction to bile flow and calls for the liver to be examined without delay.

How it is treated

Most babies need no treatment at all — frequent feeds and observation are enough. When the level approaches the danger mark, phototherapy is used.

This is a lamp giving blue-green light of a particular wavelength. The light penetrates the skin and changes the shape of the bilirubin molecule so that it can leave in the urine and bile without going through the liver enzyme. The baby lies undressed in a cot or incubator with the eyes covered, and temperature and weight are watched because more fluid is lost under the lamp. Treatment is paused for feeds and cuddles; if bilirubin is climbing fast, lamps are placed on several sides and the breaks are shortened. The level is rechecked every few hours and the lamp comes off once it falls, which usually takes a day or two. Side effects are limited to loose stools and a mild rash.

Putting the baby in the sun instead of under a lamp is not an option. It has no therapeutic effect, and burning such thin skin or making the baby too cold or too hot is easy. Sunlight through window glass is even less use.

If the figures are very high, or rising faster than phototherapy can hold, an exchange transfusion is carried out: the baby's blood is replaced in small portions with donor blood through a catheter, taking with it both the bilirubin and the antibodies attacking the red cells. It takes several hours and is done under continuous monitoring. Where blood groups are incompatible, intravenous immunoglobulin may be given beforehand to slow the destruction of red cells. If an infection or a thyroid disorder lies behind the jaundice, the underlying cause is treated.

All of this has one aim: to keep bilirubin out of the brain. That injury is called kernicterus, and it is rare today precisely because bilirubin is measured and brought down in time. Its first signs are unusual drowsiness, refusal to feed, a high-pitched monotonous cry and floppy, rag-doll muscles, followed by the opposite — head thrown back, arched spine, seizures. In children who survive, the consequences last a lifetime: movement disorders, deafness, developmental delay. That is why a bilirubin figure is taken seriously even when the baby looks well.

When to act immediately

Call an ambulance or take the baby straight to hospital, without waiting for an appointment, if a jaundiced baby:

• is unusually drowsy, cannot be woken, or refuses the breast and the bottle;
• has a cry that has become sharp, high-pitched and monotonous;
• has gone floppy or, conversely, arches the back and throws the head backwards;
• has seizures, pauses in breathing, or turns blue;
• has a temperature above 38 °C or, the other way round, feels cold to the touch.

See a doctor the same day if jaundice is visible in the first 24 hours of life, if it is deepening quickly or spreading below the navel, if the urine is dark and the stools white or pale grey, if the baby is passing little urine, losing weight, or still yellow after two weeks. The single European emergency number is 112.

Online consultation

A video appointment is convenient in exactly those first weeks, when taking a newborn out to a clinic is the last thing you want. The doctor will go through what actually decides the case: which day the yellow appeared, how it is changing, how much the baby feeds and how many nappies are wet, the colour of urine and stools, how the birth went and the mother's blood group. You will be asked for a photograph taken in daylight, given advice on establishing feeding, and helped to make sense of any tests already done.

The main job of such a consultation is to set the urgency: watch at home, go for a bilirubin measurement today, or head to hospital straight away. The measurement itself cannot be done remotely, so if any doubt remains the doctor will arrange a face-to-face examination and a test.

This material is for information only and does not replace medical advice.