Is “breast milk jaundice” the correct diagnosis?

Clinicians should refrain from making a diagnosis of “breast milk jaundice” because it is often inappropriate, results in unnecessary discontinuation of breastfeeding, and by delaying accurate identification of the etiology for the symptom, may expose the child to undue risk of severe neonatal hyperbilirubinemia.

“Breast milk jaundice is not a diagnosis,” said Vinod K Bhutani, MD. “Whenever a baby has jaundice beyond 2 weeks of age, the clinician needs to look harder for the true etiological cause.”

Dr Bhutani is Professor of Pediatrics, Stanford University, Stanford, California. He spoke in a session entitled “Jaundice: sometimes more than yellow!” on Sunday, October, 25.

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Dr. Bhutani encouraged using the diagnosis of “prolonged unconjugated jaundice” rather than “breast milk jaundice”, and he noted that genetic conditions affecting bilirubin elimination are the leading underlying cause. Among those disorders, the 2 most common are Gilbert syndrome and glucose-6-phosphate dehydrogenase deficiency (G6PD) syndromes.

Gilbert syndrome, which is due to a mutation in the promoter of a gene encoding bilirubin conjugating enzyme UDP-glucuronosyltransferase, is associated with delayed hepato-biliary excretory maturation. It contributes to prolonged unconjugated jaundice in breastfed infants, but the vast majority of infants with Gilbert syndrome have a benign unconjugated hyperbilirubinemia. Gilbert syndrome may precipitate more severe jaundice when the mutation is co-inherited with other disorders of heme metabolism.

Clues to the diagnosis of Gilbert syndrome come from family history and also maternal race. Although Gilbert syndrome is the most common syndrome known in humans, with a prevalence of about 6% in the US population, it occurs predominantly in Caucasians or when co-inherited with G6PD deficiency and other congenital hemolytic syndromes.

Potentially more worrisome are G6PD deficiency syndromes, which when triggered by an oxidant (drugs, chemicals, herbs, dietary substances, or infection) can result in excessive bilirubin load from increased production and delayed elimination. These manifestations may develop slowly (over several days) or be fulminant (in a matter of hours) and can potentially result in acute bilirubin encephalopathy.

Suspicion for G6PD deficiency is based on clinical history along with maternal race/ethnicity, with the prevalence being highest in African-Americans. Contrary to prevailing belief, it should be considered in both boys and girls.

Diagnosis in the high-risk population, including children with increased bilirubin levels for age in hours is confirmed by quantitative enzyme assay.

“Timely intervention with effective phototherapy is of proven benefit to reduce the bilirubin load. Thus, there is essentially no evidence to discontinue breastfeeding,” Dr Bhutani said.