Neonatal Jaundice
last authored: Dec 2011, David LaPierre
last reviewed: Jan 2012, Soumyadeep Bhaumik
Introduction
Courtesy of Global Health Media Project
Neonatal jaundice, is one of the commonest issues affecting newborns. It is observed in upto 60% of term infants and 80% of preterm infants. Clinically, jaundice appears as yellowness of skin due to of elevated bilirubin ( a breakdown product of hemoglobin) levels above 85-120 umol/L, or 5-6 mg/dL.
Most jaundice is "physiologic" and self-limited. Physiologic jaundice normally occurs postpartum day 2-3, peaking by the fourth day, and resolving by 7 days. Premature infants have longer duration.
However, diffentiation between physiologic jaundice, which does not require any intervention and pathologic jaundice, which if untreated is potentially neurotoxic and most often lethal is of utmost clinical importance.
The Case of Baby Daniel
Daniel is an infant born to a mother who received no prenatal care during her pregnancy. Based on her estimation, Daniel was born at 39 weeks gestational age. Her labour and delivery were uneventful, and he was born with APGAR scores of 9 and 9 at 1 and 5 minutes, respectively. However, his nurse immediately noticed that he had a strong yellow colour to his skin, and because concerned about the possibility of jaundice.
- should she be concerned?
- what might be causing jaundice in Daniel?
- what tests and treatments do you consider?
Physiological Jaundice
jaundice, from Wikipedia
Most of the cases of neonatal jaundice is physiological in nature and is not worrisome. It has some specific features:
- Appears between 1day and 3 day
- Maximum intensity on 4th and 5th day
- Peak serum bilirubin levels never exceed 15mg/dl
- Disspaears by 14 th day usually
In preterm babies, the peak may be seen a little later and biliribun levels may be slightly higher and lasts slightly longer.
The fact that the nature of jaundice (i.e whether physiological of pathological) cannot be determined by a single examination; it has to be observed over a period of time, and if required investigations done and only then commented upon.
Mothers are often anxious on hearing the word “jaundice” It is important to counsel them that physiological jaundice is benign and has bo long term sequlae either. In developing nations of South Asia, mothers often want to give babies extra glucose water. This should be counselled against and breast feeding may be advised instead.
Causes and Risk Factors
Various causes of jaundice are described below. Alongside these, increased circulating bilirubin is seen with:
- East Asian, Mediterranean native American heritage
- prematurity
- traumatic delivery
- infection
- hemolysis
- acidosis
- hypoalbuminemia
- non-optimal feeding/dehydration (formula or inadequate breast milk)
- drugs
- polycythemia
- metabolic deficiency
Pathophysiology
Newborns have high levels of hemoglobin, which is converted to biliverdin and then bilirubin. Uncongugated bilirubin is not water-soluble, and is transported through the blood on albumin to the liver, where it is congugated by gluconuryl transferase to form 'direct' bilirubin, water-soluble bilirubin that can be excreted into the urine or stool.
Physiologic jaundice occurs due to increased hematocrit, slow functioning of glucuronyl transferase, and increased enterohepatic circulation.
Increased destruction of bilirubin, such as by hemolysis, hematoma, or other causes, will result in high levels of uncongugated bilirubin.
Decreased gastrointestinal motility will also increase bilirubin levels.
Direct hyperbilirubinemia can be increased by infection, metabolism disorders, liver dysfunction, or obstruction of the bile ducts.
Bilirubin retention is increased by prematurity, acidosis, hypoalbuminemia, and dehydration.
Differential Diagnosis
Unconjugated (Indirect)
non-hemolytic
hemolytic
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Conjugated (Direct)infections
obstruction (eg biliary atresia) TPN feeding medications hepatitis a1-antitrypsin deficiency cystic fibrosis
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Presentation By Age
Early (< 24 hours)Early presentation is almost always pathological. Common causes include:
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Typical (24-96 hours)
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Late Presentation
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History and Physical Exam
- history
- physical exam
History
Jaundice may be present at birth or may reappear later at time. Though mothers are usually alert and will inform the health care provider, a routine check for jaundice is recommended for each visit in the entire neonatal period.
age of infant (as described above)
pregnancy and birth history
- infections
- blood type
general state of infant
- dehydration
- lethargy (hypothyroidism)
- increased sleeping
family history/ethnicity
- maternal history of diabetes
- hemolytic disease of the newborn
- G6PD deficiency
feeding type and history
- is the infant gaining weight?
- breastfed vs formula?
- total parental nutrition?
- voiding and stooling
Physical Exam
- vitals
- weight assessment
- skin and scleral colour; look particularly at the mucous membranes, nose, and palmar creases
- signs of hematoma or bruising
- liver and spleen exam
A very important feature of neonatal jaundice (whether pathological or physiological) is the fact that its locational extent can be used to estimate bilirubin levels:
- face: 5mg/dl
- abdomen and upper chest: 15 mg/dl
- soles/palm: 20mg/dl
Investigations
Routine bloodwork will reveal relative levels of direct and indirect bilirubin.
Investigations are required if jaundice appears pathological clinicially (is seen within the first day, if jaundice persists beyond one week). Identification of the cause is usually straightforward.
- lab investigations
- diagnostic imaging
Lab Investigations
Bilirubin is most frequently measured by transcutaneous means.
Bloodwork is required to detect levels of direct (conjugated) bilirubin. This can be subtracted from total levels to yield indirect, or uncongugated bilirubin.
The online BiliTool provides free assessment of neonatal risks, according to age (in hours) and bilirubin level. The American Association of Pediatrics also has an hour-specific nomogram.
If causes are unclear, tests to consider include:
- WBC count: infection
- Rh and ABO status of mother and infant
- blood and urine cultures, lumbar puncture
- peripheral smear
- reticulocyte count
- Coomb's: hemolytic disease
Other tests to consider include:
- G6PD levels
- TSH
- albumin
If bilirubin is conjugated, consider:
- liver enzymes
- INR, PTT
- ammonia
- TORCH screen
- galactosemia
- metabolic screen
Diagnostic Imaging
A chest X ray may be done to assess for pneumonia, if infection is a concern.
If direct bilirubin levels are elevated, consider:
- abdominal ultrasound
- HIDA scan
Management
Indirect
Infants with physiological jaundice require only monitoring. If breastfeeding is a concern, discuss strategies for effective feeds. This can include latching, adequate hydration in the mother, and pumping as necessary. Supplementation may be necessary as the milk supply comes in.
If pathologic jaundice is suspected, all efforts should be pursued to prevent the development of long-term damage (described below). Early feeding and maintenance of adequate hydration is essential. Acidosis/hypoxia/hypothermia/hypoglycaemia is to be prevented. Also appropriate antibiotics should be given in cases of infection, and many physicians advocate the use of prophylactic antibiotics. Administration of Vitamin K injections are also predispose to the development of kernicterus by aggravating haemolysis.
The most common treatment is phototherapy, which alters bilirubin in blood vessels with ultraviolet light to allow for excretion in the urine.
Treatments, in increased order of efficacy, include:
- sunbathing
- biliblanket (allows babies to be held by parents)
- bilibed: requires less nursing support
- double-bank white phototherapy (DBWL): requires incubator, and can be very distressing)
- blue light phototherapy (usually done in NICU, and used by many hospitals)
Phototherapy is often given when bilirubin levels reach 10 to 12 mg/dl for preterms and 15mg/dl for term infants. Specific guidelines for directing treatment can be found according to AAP phototherapy nomogram.
Complications of treatment include parental distress (especially about eye-covering), interference with bonding and feeding, watery stools, increased temperature, skin rashes, and bronzed-baby syndrome (if high levels of direct bilirubin are present).
If phototherapy is insufficient, double-volume exchange transfusion done through the umbilical vein can be effective, though with serious complications. The decision for exchange transfusion is guided by a multitude of factors in addition to the levels of unconjugated bilirubin levels like gestational maturity , postnatal age, presence or absence of perinatal distress factors and cause of jaundice.Other newer treatments include tin mesoporphyrin.
Direct
Direct hyperbilirubinemia requires treatment of the underlying condition.
Consequences
Elevated levels of unconjugated bilirubin can cross the blood-brain barrier and enter the brain, where it acts as a neurotoxin and causes CNS damage, termed kernicterus, or bilirubin encephalopathy. Kernicterus can cause:
- first few days: lethargy, poor feeding, vomiting, high pitched cry, seizures, decreased tone
- first week: opisthotonos, fever, increased tone, bulging fontanelles, pulmonary hemorrhage
- chronic: hearing damage, strabismus, mental retardation, cerebral palsy, death
Conjugated (direct) bilirubin cannot enter the brain and so does not cause kernicterus. However, the conditions that lead to jaundice can have life-threatening consequences of their own.
Resources and References
Topic Development
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