Physiologic Jaundice and Breast Milk Jaundice

Jaundice in the normal neonate is due to:

1. increased bili production: increased RBC mass, lower life span (80 days; normal is 100-120 days)
2. decreased UCB albumin concentrations and binding capacity
3. immature hepatocyte uptake
4. decreased activity of UDPGT (Uridine diphosphate glucuronosyl (some sources say glucuronyl) transferase) (Note in Crigler-Najjar Type I this enzyme is absent or completely nonfunctional. In Crigler-Najjar Type II aka Arias syndrome, the enzyme is functional but decreased - phenobarb can help reduce bili levels in Arias)
5. impaired canalicular secretion
6. increased enterohepatic circ of UCB, due to presence of B-glucuronidase, a hydrolyzing/deconjugating enzyme, in intestinal lumen... UCB is more easily reabsorbed
7. decreased bacterial flora... diminished urobili formation

Indirect (unconjugated) bili: (mg/dL)

1. cord blood 1-3
2. rises less than 5 mg/24 hr
3. jaundice becomes visible on DOL 1-2, peaking DOL 3-5
4. preemie kids, starts later between dol 3-7, peaking at 8-12.
5. DOL 4-7 decreases back down <2
6. Decline to adult level (=1) by 2 weeks

• maternal DM
• race (chinese, japanese, korean, native american)
• male
• preemie
• drugs (vit K, novobiocin)
• altitude
• polycythemia,
• downs
• bruising
• cephalo
• oxytocin induction
• breast feeding
• weight loss
• delayed bowel movement
• sib with physiologic jaundice

Breast feeding jaundice

1. "Early" or "Breast-Feeding jaundice". In 1st 5 days of life. T.bili > 13 in 10-25% of breast fed, vs 4-7% of formula fed. Due to decreased milk intake, slight dehydration, and increased enterohepatic circulation. Encourage freq br feeding, >10.24hr), rooming in w/ night feeds, discouraging D2W or water supplementation (because of reduced overall caloric intake)
   1. 75%ile for TSB levels (low intermediate risk). Consider workup if beyond these levels (ie. type and coombs, CBC, consider G6PD, esp in black infant.
      1. DOL 1 (<24 hours): 6
      2. DOL 2: 6-11
      3. DOL 3: 11-13
      4. DOL 4: 13-15
      5. DOL 5: 15-16. Peaks here. In preemies and breast fed infants, peak is relatively higher and lasts longer
      6. by DOL14: normal bili, CB <20%
      7. Example: Jaundice in a severely bruised infants needs no further explanation, a 4-5 day old breast fed infant with TSB is 16 doesn't need further workup, but does require monitoring to ensure that the bilirubin level does not becomes excessive. When doing a serum TSB, also use your hand-held machine to correlate and simplify future measurements.
2. "late" or Breast Milk Jaundice. occurs after 1st week of life, peaks in 2nd/3rd week of life at 10-30 mg/dl.  Theories include inhibition of glucuronyl transferase activity and increased enterohepatic circ of UCB. If breast feeding is continued, levels gradually decrease and persist at low levels for 3-10 weeks. Stopping breast feeding for 1-2 days can result in rapid decline.
3. No tx necessary.
4. If bili >20 m/dL in breast fed infant, d/c'ing br feed x 24 hours can result in decreased bili level.
5. any red flags? fractionate bili.