Breast Milk Jaundice Workup

Updated: Nov 18, 2021
  • Author: Prashant G Deshpande, MD; Chief Editor: Muhammad Aslam, MD  more...
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Laboratory Studies

Breast milk jaundice (BMJ) is a diagnosis of exclusion. Note the following:

  • A detailed history and physical examination showing that the infant is thriving and that lactation is well established are key elements to diagnosis. Breastfed babies should have 3-4 transitional stools and 6-7 wet diapers per day, and they should have regained their birth weight by the end of the second week of life or demonstrate a weight gain of 1 oz/day.

  • Measure the total serum bilirubin concentration in neonates who have jaundice that has progressed from the face to the chest, as well as in neonates who are at risk for hemolytic disease of the newborn.

Consider obtaining the tests discussed below if serum bilirubin levels are greater than 12 mg/dL (170 µmol/L). A total serum bilirubin concentration that rises faster than 5 mg/dL/d (85 µmol/L/d) or jaundice before 24 hours of life suggests pathologic jaundice.

A level of conjugated bilirubin greater than 2 mg/dL (34 µmol/L) suggests cholestasis, biliary atresia, or sepsis (see Neonatal Jaundice).

A complete blood cell (CBC) count with reticulocyte count. Findings may include the following:

  • Polycythemia (hematocrit level >65%)

  • Anemia (hematocrit level < 40%)

  • Neutropenia, high neutrophil count, and/or a predominance of immature polymorphonuclear neutrophil forms to total neutrophil ratio above 0.2: These finding suggest sepsis

Urine specific gravity can be useful in the assessment of hydration status.

If hemolysis is suspected, consider the following tests:

  • Blood type of mother and infant to evaluate for ABO, Rh, or other blood group incompatibility

  • Coombs test, as well as an elution test for antibodies against A or B, to evaluate for immune mediated hemolysis

  • Peripheral smear to look for abnormally shaped RBCs (ovalocytes, acanthocytes, spherocytes, schistocytes)

  • Glucose-6-phosphate dehydrogenase (G6PD) screen, especially if the infant's ethnicity is consistent (eg, black persons, Southeast Asians)

Factors that suggest the possibility of hemolytic disease include the following:

  • Family history of hemolytic disease

  • Onset of jaundice before 24 hours of life

  • Rise in serum bilirubin levels over 0.5 mg/dL/h

  • Pallor, hepatosplenomegaly

  • Rapid increase in serum bilirubin level after 24-48 hours (G6PD deficiency)

  • Ethnicity suggestive of G6PD deficiency

  • Failure of phototherapy to lower bilirubin levels

  • History of Rh-negative mother who did not receive RhoGAM in previous pregnancies when indicated

If sepsis is suspected, consider the following tests:

Clinical factors that suggest the possibility of sepsis include the following:

  • Poor feeding

  • Vomiting

  • Lethargy

  • Temperature instability

  • Apnea

  • Tachypnea

Signs of cholestatic jaundice that suggest the need to rule out biliary atresia or other causes of cholestasis include the following:

  • Dark urine or urine positive for bilirubin

  • Light-colored stools

  • Persistent jaundice for more than 3 weeks

During follow-up of the newborn state, screen for galactosemia and hypothyroidism.