Breast milk jaundice is a type of neonatal jaundice associated with breastfeeding and characterized by an increase in levels of indirect bilirubin in a newborn on breastfeeding.
It develops in the first week of life and persists longer than physiologic jaundice, and has no other identifiable cause.
Breast milk jaundice is different from breastfeeding jaundice, which occurs in the first 3 days of life and is due to insufficient intake of breast milk or insufficient production.
Pathophysiology of Breast Milk Jaundice
The cause of breast milk jaundice is not clearly understood, but the following factors have been suggested:
- Inhibition of Glucuronyl transferase [An enzyme used in the breakdown of bilirubin]
- Pregnane-3-alpha 20 beta-diol is a substance in the breast milk that inhibits glucuronyl transferase
- Increased concentrations of nonesterified free fatty acids in milk inhibit hepatic glucuronyl transferase
- Increased enterohepatic circulation of bilirubin due to increased content of beta-glucuronidase activity in breast milk. This leads to the delayed establishment of enteric flora in breastfed infants.
- Defects in uridine diphosphate-glucuronyl transferase.
- Mutation resulting in reduced hepatic uptake of unconjugated bilirubin.
- Inflammatory cytokines like interleukin IL-1 beta and IL-6.
- High epidermal growth factor (EGF) level in breast milk was noted in patients with breast milk jaundice.
- Delayed milk production and poor feeding lead to decreased caloric intake, dehydration, and increased enterohepatic circulation, resulting in higher serum bilirubin concentration.
Presentation of Breast Milk Jaundice
It is important to differentiate breast milk jaundice from physiological neonatal jaundice so that course and duration could be predicted.
Physiologic jaundice usually manifests after the first 24 hours of life. This can be accentuated by breastfeeding, which, in the first few days of life, may be associated with suboptimal milk and suboptimal caloric intake, especially if milk production is delayed. This is known as breastfeeding jaundice.
Jaundice that manifests before the first 24 hours of life should always be considered pathological until proven otherwise.
Breast milk jaundice, in the true sense, manifests after the first 4-7 days of life. There is a second peak in serum bilirubin levels around the age of 14 days.
Depending on serum bilirubin concentration, neonates with hyperbilirubinemia may become sleepy and feed poorly.
Clinical jaundice is usually first noticed in the sclera and the face. Then it progresses caudally to reach the abdomen and extremities.
Neurologic examination, including muscle tone and neonatal reflexes, should be normal. The child may be sleepy.
- Acute Anemia of newborn
- Galactose-1-Phosphate Uridyltransferase Deficiency
- Hemolytic disease of Newborn
- Neonatal hypothyroidism
- Neonatal physiological jaundice
- Neonatal sepsis
- Polycythemia of the newborn
Factors that suggest the possibility of hemolytic disease:
- Family history of a hemolytic disease
- Onset of jaundice before 24 hours of life
- Rise in serum bilirubin levels of more than 0.5 mg/dL/h
- Pallor, hepatosplenomegaly
- Ethnicity suggestive of G-6-PD deficiency
- Failure of phototherapy to lower bilirubin level
Factors that suggest the possibility of sepsis:
- Poor feeding
- Temperature instability
Signs of cholestatic jaundice [Biliary atresia or other causes of cholestasis]
- Dark urine
- Urine positive for bilirubin
- Light-colored stools
- Jaundice> 3 weeks
Lab investigations are done on similar lines of jaundice. There is no lab test to identify breast milk jaundice as such and the diagnosis is one of exclusion.
- Total serum bilirubin concentration when jaundice has progressed from the face to the chest
- If serum bilirubin levels are >12 mg/dL (170 µmol/L)
- Conjugated bilirubin levels [Levels> 2 mg/dL (34 µmol/L) suggests cholestasis, biliary atresia, or sepsis]
- CBC [complete blood count] – Polycythemia if hematocrit level>65% and anemia if <40%
- Blood culture, WBC total and differential counts, platelet count, urine analysis and culture for sepsis
- Urine specific gravity for hydration status.
- In case of hemolysis
- Blood type to evaluate for ABO, Rh or other blood group incompatibility
- Coombs test, as well as an elution test for antibodies against A or B
- Peripheral smear to look for abnormally shaped RBCs
- Glucose-6-phosphate dehydrogenase (G-6-PD) screening
In preterm, anemic, or ill infants, those with early (< 24 h) or severe jaundice (>25 mg/dL or 430 µmol/L) the treatment guidelines are different.
- For healthy term infants with breast milk or breastfeeding jaundice and bilirubin levels <12 mg/dL to 17 mg/dL, increase breastfeeding to 8-12 times per day and recheck the serum bilirubin level in 12-24 hours. Temporary interruption of breastfeeding is rarely needed and is not recommended unless serum bilirubin levels reach 20 mg/dL (340 µmol/L). In case the breastfeeding needs to be interrupted, supplements should be given. Supplementation with dextrose solution is not recommended because it may decrease caloric intake and milk production and may consequently delay the drop in serum bilirubin concentration.
- For infants with serum bilirubin levels 17-25 mg/dL (294-430 µmol/L)
- Add phototherapy to any of the previous treatment. It can be administered with standard phototherapy units and fiber-optic blankets. Phototherapy can be discontinued when serum bilirubin levels drop to less than 15 mg/dL (260 µmol/L).
- Monitor daily weight and serum bilirubin concentration.
Complications and Prognosis of Breast Milk Jaundice
Bilirubin encephalopathy (kernicterus) can occur with persistently high bilirubin levels. Prognosis is generally excellent. Jaundice may persist for as long as 12 weeks.