What is the appropriate management of physiological jaundice in a healthy term newborn?

Management of Physiological Jaundice in Healthy Term Newborns

Physiological jaundice in healthy term newborns requires systematic monitoring with objective bilirubin measurement, support of breastfeeding, risk stratification before discharge, and phototherapy only when hour-specific thresholds are exceeded based on the infant's age and risk factors. 1

Definition and Timeline

• Physiological jaundice appears after the first 24 hours of life, typically peaks between days 3-5, and resolves within 1-2 weeks in term infants 2
• Jaundice occurring within the first 24 hours is always pathologic and demands immediate TSB measurement and evaluation for hemolytic disease, sepsis, or other serious causes 1, 2, 3

Systematic Monitoring Approach

• All infants must be assessed for jaundice at least every 8-12 hours during hospitalization, with nursing protocols allowing staff to obtain transcutaneous bilirubin (TcB) or order total serum bilirubin (TSB) when jaundice is detected 1, 4
• Visual estimation is dangerously unreliable, particularly in darkly pigmented infants, and should never guide treatment decisions—always obtain objective TcB or TSB measurement 1, 2
• For infants with TSB <15 mg/dL, TcB devices provide valid estimates, but TSB is required for definitive management decisions 1

Risk Stratification Before Discharge

• Every newborn requires predischarge risk assessment using TSB/TcB plotted on the hour-specific Bhutani nomogram, clinical risk factor assessment, or both 2
• Infants with predischarge bilirubin in the high-risk zone (>95th percentile) require follow-up within 24 hours of discharge 2
• Risk factors that lower phototherapy thresholds include: gestational age 35-37 weeks, isoimmune hemolytic disease (positive direct Coombs test), G6PD deficiency, sepsis, acidosis, or albumin <3.0 g/dL 2, 4

Laboratory Evaluation When Indicated

• Obtain blood type and direct antibody test (Coombs) if mother is Rh-negative or blood group O 1, 2
• If TSB is rising rapidly (crossing percentiles on nomogram) or phototherapy is needed, evaluate for underlying cause with: blood type, Coombs test, complete blood count with smear, reticulocyte count, and G6PD level 2, 4
• G6PD deficiency causes late-onset jaundice (after day 3-4) and accounted for 31% of kernicterus cases in one series—consider especially in male infants of Mediterranean, Middle Eastern, African, or Asian ancestry 2

Phototherapy Decision-Making

• Use hour-specific AAP phototherapy nomograms that incorporate exact infant age in hours (not days), gestational age, and neurotoxicity risk factors 2, 4
• For low-risk infants (≥38 weeks, well, no risk factors): use the standard phototherapy curve 2
• For medium-risk infants (≥38 weeks with risk factors OR 35-37 6/7 weeks, well): use the medium-risk curve with lower thresholds 2
• For high-risk infants (35-37 6/7 weeks with risk factors): use the high-risk curve with the lowest thresholds 2

Phototherapy Implementation

• Intensive phototherapy should maximize skin exposure using blue-green spectrum light (blue fluorescent or LED) delivering spectral irradiance >30 μW/cm²/nm 4
• Expect TSB to decrease by >2 mg/dL within 4-6 hours if phototherapy is effective 2
• Do not routinely supplement breastfed infants with water or dextrose water unless there is evidence of dehydration 1, 4
• Continue breastfeeding frequently during phototherapy to maintain hydration and promote bilirubin excretion 1

Monitoring During and After Phototherapy

• Measure TSB (not TcB) after initiating phototherapy to verify efficacy—TcB is unreliable during and for 24 hours after phototherapy due to skin "bleaching" 4
• Discontinue phototherapy when TSB falls 2-4 mg/dL below the hour-specific threshold at which it was started 4
• For infants with phototherapy initiated <48 hours of age, gestational age <38 weeks, positive Coombs test, or suspected hemolysis: obtain TSB 8-12 hours after stopping phototherapy and repeat the following day 4

Follow-Up Timing Based on Discharge Age

• Infants discharged before 24 hours must be seen by 72 hours of age 4
• Infants discharged between 24-48 hours must be seen by 96 hours of age 4
• Infants discharged between 48-72 hours must be seen by 120 hours of age 4
• High-intermediate or high-risk zone infants require follow-up within 24 hours of discharge 2

Critical Pitfalls to Avoid

• Never discharge an infant with jaundice in the first 24 hours without TSB measurement and clear follow-up plan 2
• Do not subtract direct bilirubin from total bilirubin when making phototherapy or exchange transfusion decisions 1, 4
• Do not treat 35-37 week infants as term—they require closer monitoring and have lower phototherapy thresholds 4
• Recognize that G6PD levels can be falsely elevated during active hemolysis—normal level does not rule out deficiency, and repeat testing at 3 months is necessary if suspected 2
• Any infant still jaundiced at or beyond 3 weeks requires measurement of total and direct/conjugated bilirubin to identify cholestasis, plus verification of newborn thyroid and galactosemia screening results 1, 4

Breastfeeding Support

• Promote and support successful breastfeeding as primary prevention—this is a core AAP recommendation for all healthy term and near-term newborns 1
• Assess adequacy of intake by monitoring weight, voiding pattern (should have 6+ wet diapers by day 4), and stooling pattern 4
• Inadequate breastfeeding with excessive weight loss or dehydration is a risk factor requiring closer monitoring 4