Neonatal jaundice is jaundice (yellowing of the skin and other tissues) in neonates.

• Unconjugated hyperbilirubinemia, meaning the problem occurs BEFORE the liver:
  • Non-hemolytic causes:
    • Physiological in newborns, as fetal hemoglobin is being rapidly broken down and replaced with adult hemoglobin. Also, hepatic machinery [for the conjugation and excretion of bilirubin] doesn't mature until approximately 2 weeks of age. It is often seen around the 2nd day after birth, lasting 10 days in term infants [up to 204 μmol/L], or 14 days in premature births [up to 225 μmol/L]
    • Breast milk jaundice, as breast milk may contain factors that keep the baby's liver from breaking down bilirubin. It may run in families
    • Dehydration → bilirubin will be more concentrated
    • Formula suppplementation, or malnutrition → breast milk promotes intestinal absorption of bilirubin, so less reaches the liver
    • Cephalohematoma (i.e. hemorrhage between skul and periosteum, due to rupture of blood vessels crossing the periosteum)
    • UTI
  • Hemolytic disorders, caused by:
    • Sepsis
    • Blood disorders, including:
      • Hereditary spherocytosis
      • Sickle cell disease
      • G6PD deficiency
      • ABO incompatibility
      • Rh disease
• Conjugated/direct hyperbilirubinemia, meaning the problem occurs:
  • AT the liver:
    • Infection:
      • Sepsis
      • Hepatitis
      • TORCH infections (toxoplasmosis, rubella, CMV, HSV)
    • Cystic fibrosis
    • Metabolic:
      • Galactosemia
      • Alpha-1-antitrypsin deficiency
      • Cystic fibrosis
    • Drugs
  • AFTER the liver:
    • Biliary atresia (i.e. common bile duct between the liver and small intestine is either blocked or absent)
    • Bile duct obstruction

• Yellow discoloration of the sclera, the face, extending down onto the chest, and then the extremities
  • Infants whose palms and soles are yellow, have serum bilirubin >255 μmol/l (15 mg/dL), and is more serious
• Sleepy
• Interfere with feeding

• Clinical assessment of color: → jaundiced appearance <24 hours, or >14 days indicates pathological jaundice
  • Blanching the skin by pressure, so underlying skin and subcutaneous tissue is revealed
  • Ingram icterometer, where a piece of transparent plastic with 5 transverse strips of graded yellow lines, is pressed against the nose, and matched. Bilirubin level is accordingly assigned
  • Transcutaneous bilirubinometer, a portable device, which generates a yellow xenon light passing through the subcutaneous tissue. Reflected light returns through an optic fiber, which is measured and assigned a bilirubin level
• Serum bilirubin (SBR)>85 μmol/L (5 mg/dL), which is more than double the amount required to cause jaundice in adults (>34μmol/L). Serum bilirubin is differentiated in results into Unconjugated bilirubin ("indirect" and Conjugated bilirubin ("direct" → total bilirubin >331.5 μmol/L, or direct/conjugated bilirubin >34μmol/L indicates pathological jaundice

Patient information

Why is the threshold for bilirubin double that which is permitted in adults ?
Because the machinery in the liver that processes bilirubin doesn't mature until around 2 weeks of age. That's why it's normal to have bilirubin levels double that in newborns, as supposed to adults .

• Hx:
  • Hx of illness → infection
  • FH of jaundice
  • FH of anemia → hemolytic disorder
  • FH of neonatal death due to liver disease → liver disease
  • Maternal illness (fever, rash, lymphadenopathy) → infection
  • Maternal drugs → sulfonamides, antimalarials causing RBC destruction in G6PD deficiency
• Clinical assessment:
  • Presence of IUGR
  • Intrauterine infection, which can be evidenced by cataracts, small head, hepatomegaly, splenomegaly → infection
  • Cephalohematoma → hemolytic disorder
  • Bruising → hemolytic disorder
  • Signs of bleeding in the ventricles → hemolytic disorder
• Maternal blood group and RBC antibodies → hemolytic disease
• Using baby's cord blood:
  • Blood group → hemolytic disease
  • DAT/Coombs test → ABO incompatibility/hemolytic disease
  • FBC → hemolysis, unusually shaped RBC's, evidence of infection
  • CRP → infection
• Billirubin with differential (conjugated, unconjugated)
• LFT → liver disease

Serum bilirubin normally subsides without intervention. Tx includes:

• Frequent and effective feedings → bilirubin is reduced through bowel movements and urination
• Bili light (i.e. exposing baby to intensive phototherapy) often used in any newborn w/ serum bilirubin>=360μmol/L → blue light (wavelengths at 458nm) oxidize bilirubin to biliverdin
  • Sunbathing is also effective, with the advantage of UV-B which promotes vitamin D production. This condition has also been rising due to less time spent outdoors
• Exchange transfusions (i.e. exchange of a person's own blood cells with replacement products), in any newborn w/ bilirubin>428 μmol/l

• Extreme jaundice can cause kernicterus (i.e. bilirubin-induced brain dysfunction, because bilirubin is highly neurotoxic), which presents w/ fever, seizure, high pitched crying

• Common in newborns, affecting >60% of babies in the 1st week of life

Patient information

Is jaundice in newborns really common?
Yes. 60% will have it in their first week of life. You're not alone .

• Jaundice