Jaundice in a 4-week-old: a prolonged neonatal jaundice case to work up

Why jaundice lasting beyond the first two weeks of life matters

Jaundice in the first week is common and usually harmless. Jaundice still present after two weeks in a term baby (three in a preterm one) is called prolonged jaundice, and most of it is benign too. The point of the work-up is to find the small number of babies with liver disease, where a delay of weeks changes the outcome.

What to ask in the history

• When the jaundice started and whether it is getting better or worse
• Stool colour: yellow, pale, or chalky white
• Urine colour: pale, or dark yellow and staining the nappy
• Feeding: breast or formula, how often, how well
• Weight gain since birth
• Birth history: gestation, birth weight, any early jaundice needing phototherapy
• Mother's and baby's blood groups; family history of jaundice, anaemia, G6PD deficiency or liver disease
• Vomiting, poor feeding, sleepiness, constipation
• Results of the newborn screening tests, if done

Red flags

• Pale or chalky stools, or dark urine
• A raised conjugated (direct) bilirubin
• Poor feeding, lethargy or poor weight gain
• An enlarged liver or spleen
• Bleeding or bruising
• Jaundice that is getting deeper rather than fading

What to examine

• Extent of jaundice, and pallor
• Weight, length and head circumference plotted on a chart
• Hydration and general alertness
• Abdomen: liver and spleen size
• Signs of hypothyroidism: large tongue, umbilical hernia, dry skin, sluggishness
• Dysmorphic features, heart murmurs
• Look at a nappy: stool and urine colour

First investigations

• Total and conjugated (direct) bilirubin, the single most important first test
• Full blood count and blood film, reticulocyte count
• Blood group and direct antiglobulin (Coombs) test
• G6PD level
• Thyroid function (TSH and free T4)
• Urine culture
• Liver function tests if the conjugated fraction is raised

Differential diagnosis of jaundice lasting beyond the first two weeks of life

Grouped, not ranked. Which one fits this patient is for you to work out in the case.

Common mistakes

• Calling it breast milk jaundice without checking the conjugated bilirubin. That one test separates benign causes from ones that cannot wait.
• Not asking about, or looking at, the stool. Parents rarely mention pale stools unless asked.
• Reassuring a baby who is not gaining weight.