Infant jaundice: types, causes and the role of feeding difficulties

Jaundice is common in newborn babies, but it is important to understand that it has several possible causes. While many cases are temporary and resolve without treatment, some require prompt investigation and medical intervention.

Feeding difficulties can contribute to certain types of jaundice. In some babies, restricted tongue movement associated with tongue-tie may be one factor affecting feeding effectiveness and milk transfer. However, tongue-tie does not directly cause jaundice, and jaundice should never be attributed to feeding difficulties without appropriate clinical assessment.

This article explains the different types of infant jaundice, how feeding can be involved, and when families should seek medical advice.

What is infant jaundice?

Jaundice is the yellow appearance of the skin and the whites of the eyes caused by an increased concentration of bilirubin in the blood. Bilirubin is a yellow pigment produced when red blood cells are broken down.

Newborn babies have a relatively high turnover of red blood cells, and their livers are still developing the ability to process and eliminate bilirubin efficiently. Bilirubin is processed by the liver and excreted primarily through the bowel. In newborns, this process can be slower, allowing bilirubin to accumulate temporarily (Maisels, 2015).

Jaundice is common during the first days after birth. However, the appearance of jaundice alone cannot establish its cause or indicate how high the bilirubin level is. Bilirubin needs to be measured when clinically indicated, and the result interpreted in relation to the baby’s age in hours, gestational age and other risk factors (NICE, 2023).

Types of infant jaundice

The table below summarises some of the main types and causes of jaundice in newborn babies. These categories can overlap, and a baby may have more than one contributing factor.

| Type of jaundice | Main cause or contributing factors | |---|---| | Physiological jaundice | Normal newborn red blood cell turnover combined with the liver’s developing ability to process bilirubin. | | Suboptimal intake hyperbilirubinaemia | Insufficient milk intake, which can reduce stool output and increase bilirubin reabsorption from the bowel. | | Breast milk jaundice | Persistent unconjugated hyperbilirubinaemia in some otherwise well babies receiving human milk, involving factors that affect bilirubin metabolism and elimination. | | Haemolytic jaundice | Increased breakdown of red blood cells, for example due to blood group incompatibility or certain inherited conditions. | | Jaundice associated with bruising or bleeding | Breakdown of blood collected in bruising, a cephalohaematoma or other bleeding. | | Jaundice associated with infection or systemic illness | Infection or other illness affecting bilirubin production, processing or elimination. | | Cholestatic jaundice | Impaired bile flow, which may be associated with liver or bile duct disease. This requires prompt investigation. | | Other medical causes | Conditions such as hypothyroidism or inherited metabolic disorders may cause or contribute to prolonged jaundice. |

(NICE, 2023; Maisels, 2015; Flaherman and Maisels, 2017; Feldman and Sokol, 2021.)

Physiological jaundice

Physiological jaundice is the common, expected form of newborn jaundice. It usually becomes noticeable after the first 24 hours of life and is often most apparent around days three to five.

It occurs because newborn babies produce bilirubin as red blood cells are broken down, while their liver’s capacity to process and eliminate bilirubin is still maturing. In many babies, the bilirubin level falls as their liver function develops and feeding becomes established.

Although physiological jaundice is common, it should not automatically be assumed to be harmless. The bilirubin level may rise sufficiently to require treatment, and the timing, severity and progression of jaundice all matter. Jaundice appearing during the first 24 hours of life is particularly concerning and requires urgent medical assessment (NICE, 2023).

Suboptimal intake hyperbilirubinaemia and “breastfeeding jaundice”

Suboptimal intake hyperbilirubinaemia occurs when a baby does not receive enough milk. It often becomes apparent during the first few days after birth, particularly when feeding is not yet established.

Insufficient milk intake can reduce the frequency and volume of bowel movements. As a result, bilirubin may remain in the bowel for longer and be reabsorbed into the bloodstream rather than being eliminated in the stool. This can contribute to rising bilirubin levels (Flaherman and Maisels, 2017).

The term “breastfeeding jaundice” has traditionally been used to describe jaundice associated with inadequate milk intake during breastfeeding. However, this terminology can be misleading because it may suggest that breastfeeding itself causes jaundice. The relevant issue is whether the baby is receiving sufficient milk, not the feeding method alone. Babies receiving expressed human milk or formula can also develop jaundice if their intake is insufficient.

Potential signs of feeding difficulties include:

• Feeding that is persistently ineffective or poorly coordinated.

• Difficulty maintaining sucking or becoming exhausted during feeds.

• Limited audible or visible swallowing.

• Feeding sessions that do not appear to result in effective milk transfer.

• Fewer wet or dirty nappies than expected for the baby’s age.

• Excessive weight loss or failure to gain weight as expected.

• Increasing sleepiness or difficulty sustaining feeds.

These signs do not establish the cause of jaundice, and some babies with inadequate intake will not show every sign. Assessment should consider the baby’s clinical condition, bilirubin level, weight, hydration, output and feeding effectiveness.

Breast milk jaundice

Breast milk jaundice is distinct from jaundice associated with suboptimal milk intake. It describes persistent unconjugated hyperbilirubinaemia in some babies receiving human milk who are otherwise clinically well and feeding and growing adequately.

It may continue for several weeks and, in some cases, for up to three months. Research has investigated components of human milk and their possible effects on bilirubin metabolism, but the mechanisms are complex and are not fully understood (Preer and Philipp, 2011; Gao et al., 2023).

Breast milk jaundice should not be diagnosed simply because a baby is breastfed and remains yellow. Other causes of prolonged jaundice need to be considered, including conditions that affect the liver, bile flow or the breakdown of red blood cells.

Breastfeeding can usually continue, but the baby needs appropriate assessment and monitoring. Families should not stop breastfeeding or change feeding plans without advice from the baby’s healthcare team.

Haemolytic jaundice

Haemolytic jaundice occurs when red blood cells break down more rapidly than usual, producing increased amounts of bilirubin.

One possible cause is blood group incompatibility between the birthing parent and baby. Other causes include inherited red blood cell conditions, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Haemolysis can cause bilirubin to rise quickly. Jaundice developing within the first 24 hours of life is a particularly important warning sign because it may indicate an underlying pathological cause. Urgent assessment and investigations are required to identify the cause and determine whether treatment is needed (NICE, 2023; Maisels, 2015).

Jaundice associated with bruising or bleeding

Babies may develop bruising during birth, and some develop a cephalohaematoma, which is a collection of blood beneath the scalp’s outer covering. As the collected blood breaks down, bilirubin is released, potentially increasing the bilirubin level.

The presence of bruising does not rule out other causes of jaundice. The baby’s overall condition, bilirubin level and any other risk factors still need to be assessed.

Jaundice associated with infection or other illness

Infection and other medical conditions can affect bilirubin production, processing or elimination. Jaundice may occur alongside other signs of illness, although the signs are not always obvious at first.

A baby with jaundice who is unwell, unusually sleepy, feeding poorly or showing changes in temperature or breathing requires urgent assessment. Jaundice should not be assumed to be physiological or feeding-related when a baby appears unwell.

Conjugated hyperbilirubinaemia and cholestasis

Not all jaundice is caused by unconjugated bilirubin. Conjugated hyperbilirubinaemia occurs when the level of conjugated bilirubin in the blood is raised. This can indicate a problem with the liver or the flow of bile, known as cholestasis.

One important cause is biliary atresia, a rare condition in which the bile ducts are blocked or absent. Early recognition and specialist assessment are important because treatment outcomes can depend on timely diagnosis.

Pale, chalky or cream-coloured stools and dark urine that stains the nappy are important warning signs. These findings should not be attributed to normal newborn jaundice or breast milk jaundice. They require prompt medical investigation (NICE, 2023; Feldman and Sokol, 2021).

Prolonged jaundice

Jaundice that continues beyond the expected period needs assessment, even if the baby otherwise appears well.

NICE recommends further assessment when jaundice lasts more than 14 days in babies born at 37 weeks’ gestation or later, or more than 21 days in babies born before 37 weeks. Investigations may include measuring conjugated bilirubin and checking for other causes, according to the baby’s clinical circumstances (NICE, 2023).

Breast milk jaundice is one possible explanation for prolonged jaundice, but it should not be assumed to be the cause before other important conditions have been considered.

Can tongue-tie contribute to jaundice?

Tongue-tie, also known as ankyloglossia, describes a restriction of tongue movement associated with the lingual frenulum. Its presence alone does not establish that a baby will have feeding difficulties. The functional impact varies between babies, and assessment should consider tongue movement alongside feeding function.

In some babies, restricted tongue movement may contribute to difficulties achieving or maintaining an effective latch, generating suction, coordinating sucking and swallowing, or transferring milk efficiently. However, these difficulties can have multiple causes, and not every baby with tongue-tie experiences them.

Where feeding is ineffective, milk intake may be insufficient. If this contributes to reduced stool output and increased bilirubin reabsorption, it may be one factor in the development of suboptimal intake hyperbilirubinaemia. This is an indirect and conditional relationship: tongue-tie does not directly cause jaundice, and jaundice should never be used on its own as evidence that a baby has tongue-tie.

Feeding assessment should therefore consider the whole feeding picture, including milk transfer, swallowing, weight change, nappies, the baby’s alertness and the birthing parent’s experience where relevant. Evidence concerning frenotomy shows that outcomes are not uniform, reinforcing the importance of individual assessment and appropriate feeding support rather than assuming that every visible frenulum requires treatment (O’Shea et al., 2017; Knight et al., 2023).

What can families do if their baby has jaundice and feeding difficulties?

Medical assessment of jaundice is the priority. Feeding support is important, but it does not replace bilirubin measurement, investigation or treatment when these are indicated.

Families who suspect jaundice should contact their midwife, health visitor, GP or neonatal team promptly for advice. The urgency depends on the baby’s age, symptoms and clinical condition. Jaundice in the first 24 hours of life requires urgent medical assessment.

Where feeding difficulties are present, the healthcare team may recommend:

• Reviewing how often the baby feeds and whether they need to be woken for feeds.

• Observing a feed to assess sucking, swallowing and milk transfer.

• Monitoring the baby’s weight and wet and dirty nappies.

• Developing an individual feeding plan, including additional milk if clinically indicated.

• Arranging feeding support and follow-up to check that intake and the baby’s condition are improving.

Waking a sleepy baby to feed may be part of an agreed feeding plan, but a baby who is unusually sleepy or difficult to wake needs urgent medical assessment rather than repeated attempts to feed at home.

Effective swallowing and milk transfer are important considerations when assessing feeding. Families can read more about [swallowing and infant feeding here — insert link to the relevant Soro article].

Jaundice treatment may include phototherapy, and more intensive treatment may be necessary in severe cases. The decision depends on the measured bilirubin level and the baby’s age and risk factors. Families should follow the advice of their healthcare team and should not use sunlight as a treatment or give water to a newborn to try to reduce jaundice (NICE, 2023).

When does jaundice need urgent assessment?

Seek urgent medical advice if a baby develops jaundice after the first 24 hours of life, or if existing jaundice is worsening or not improving as expected.

A baby with jaundice needs immediate medical assessment if they:

• Are difficult to wake, unusually sleepy or floppy.

• Are not feeding or cannot feed effectively.

• Have a high-pitched cry, abnormal stiffness, arching or unusual movements.

• Have a temperature of 38°C or above, or 36°C or below.

• Have no wet nappies or show signs of significant dehydration.

• Have difficulty breathing.

• Develop jaundice within the first 24 hours after birth.

Pale, chalky stools or dark urine that stains the nappy also require prompt medical assessment. These may indicate a problem with bile flow rather than ordinary newborn jaundice.

Jaundice can be harder to recognise visually in babies with darker skin. Families should not rely on the apparent depth of the yellow colour to judge severity, and healthcare professionals should not rely on visual inspection alone to estimate bilirubin levels (NICE, 2023; NHS, n.d.).

If a baby with jaundice is difficult to wake, not feeding, floppy, having abnormal movements or experiencing breathing difficulties, seek emergency help. In the UK, call 999 or go to A&E in line with NHS advice.

Supporting the whole feeding relationship

Infant jaundice has several possible causes, and the correct response depends on identifying what is happening for the individual baby. Many babies experience temporary physiological jaundice, while others need treatment or investigation for an underlying condition.

Feeding difficulties can contribute to suboptimal intake hyperbilirubinaemia, and a functional restriction of tongue movement may be one of several factors affecting milk transfer in some babies. However, neither tongue-tie nor breastfeeding should be treated as a default explanation for jaundice.

The safest approach is timely medical assessment, appropriate monitoring and practical feeding support. Where tongue-tie is suspected, its functional impact should be assessed alongside other potential contributors to feeding difficulties. This allows the baby’s jaundice and feeding needs to be addressed without overlooking other important causes.

References

American Academy of Pediatrics (2022) ‘Clinical practice guideline revision: management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation’, Pediatrics, 150(3), e2022058859. Available at: https://doi.org/10.1542/peds.2022-058859.

Feldman, A.G. and Sokol, R.J. (2021) ‘Neonatal cholestasis: updates on diagnostics, therapeutics, and prevention’, NeoReviews, 22(12), pp. e819–e836. Available at: https://doi.org/10.1542/neo.22-12-e819.

Flaherman, V.J. and Maisels, M.J. (2017) ‘ABM clinical protocol #22: guidelines for management of jaundice in the breastfeeding infant 35 weeks or more of gestation—revised 2017’, Breastfeeding Medicine, 12(5), pp. 250–257. Available at: https://doi.org/10.1089/bfm.2017.29042.vjf.

Gao, C., Guo, Y., Huang, M., He, J. and Qiu, X. (2023) ‘Breast milk constituents and the development of breast milk jaundice in neonates: a systematic review’, Nutrients, 15(10), 2261. Available at: https://doi.org/10.3390/nu15102261.

Knight, M. et al. (2023) ‘Frenotomy with breastfeeding support versus breastfeeding support alone for infants with tongue-tie and breastfeeding difficulties: the FROSTTIE RCT’, Health Technology Assessment, 27(11), pp. 1–73. Available at: https://doi.org/10.3310/WBBW2302.

Maisels, M.J. (2015) ‘Managing the jaundiced newborn: a persistent challenge’, CMAJ, 187(5), pp. 335–343. Available at: https://doi.org/10.1503/cmaj.122117.

National Institute for Health and Care Excellence (NICE) (2023) Jaundice in newborn babies under 28 days. Clinical guideline CG98. Available at: https://www.nice.org.uk/guidance/cg98.

NHS (n.d.) Jaundice in babies. Available at: https://www.nhs.uk/conditions/jaundice-in-babies/.

O’Shea, J.E. et al. (2017) ‘Frenotomy for tongue-tie in newborn infants’, Cochrane Database of Systematic Reviews, 3, CD011065. Available at: https://doi.org/10.1002/14651858.CD011065.pub2.

Preer, G.L. and Philipp, B.L. (2011) ‘Understanding and managing breast milk jaundice’, Archives of Disease in Childhood—Fetal and Neonatal Edition, 96(6), pp. F461–F466. Available at: https://doi.org/10.1136/adc.2010.184416.