Neonatal bilirubin metabolism (Contd.) 3. Defective bilirubin conjugation a Decreased uridine diphosphate glucuronyl transferase(UDPG-T)activity 葡萄糖醛酸转移酶 b Increased uridine diphosphoglucose dehydrogenenase(B-glucuronidase)activity
Neonatal bilirubin metabolism (Contd.) 3. Defective bilirubin conjugation a. Decreased uridine diphosphate glucuronyl transferase (UDPG-T) activity 葡萄糖醛酸转移酶 b. Increased uridine diphosphoglucose dehydrogenenase (-glucuronidase) activity
Neonatal bilirubin metabolism (Contd.) 4 Decreased excretion of bilirubin Summary a Increased bilirubin production Decreased clearance of bilirubin
Neonatal bilirubin metabolism (Contd.) 4. Decreased excretion of bilirubin Summary: Increased bilirubin production Decreased clearance of bilirubin
Physiologic Jaundice Onset of jaundice: 2-3 days of age I The time of peak level: 4-6 days of age I The resolving time Full term: 2 weeks of age Preterm:3-4 weeks of age 1 Level of total serum bilirubin: <12mg/dL 1 Level of conjugated bilirubin: <1.5mg/dL
Physiologic Jaundice Onset of jaundice: 2-3 days of age The time of peak level: 4-6 days of age The resolving time: Full term: 2 weeks of age Preterm: 3-4 weeks of age Level of total serum bilirubin: <12mg/dL Level of conjugated bilirubin: <1.5mg/dL
Physical jaundice in full Term Infant
Physical Jaundice in Full Term Infant
Nonphysiologic Jaundice 1 Onset of jaundice: before 24 hours of age 1 Any elevation of serum bilirubin that requires phototherapy A rise of serum biliru bin levels of over 5mg/dL/day I Signs of underlying illness ■ Persist jaundice
Nonphysiologic Jaundice Onset of jaundice: before 24 hours of age Any elevation of serum bilirubin that requires phototherapy A rise of serum bilirubin levels of over 5mg/dL/day Signs of underlying illness Persist jaundice