Identifying newborns at risk of significant hyperbilirubinaemia: a comparison of two recommended approaches

A comparison of alternative risk-assessment strategies for predicting significant neonatal hyperbilirubinemia in term and near-term infants

OBJECTIVE

The purpose of this work was to compare the predictive accuracy of alternative risk-assessment strategies used to screen for the risk of significant neonatal hyperbilirubinemia.

PATIENTS AND METHODS

We conducted a prospective cohort study of 823 term and near-term newborns admitted to the well-infant nursery at the Hospital of the University of Pennsylvania. Maternal, infant, and delivery risk factors for significant hyperbilirubinemia were obtained from chart review, structured interviews with parents, and nurse assessments before discharge. Transcutaneous bilirubin measurement was performed daily until discharge and once by a visiting home nurse between 3 and 8 days of life. We used the c statistic to compare the predictive accuracy of 3 risk-assessment strategies for estimating the risk of significant neonatal hyperbilirubinemia, defined as a bilirubin level that at any time after birth exceeded or was within 1 mg/dL (17 micromol/L) of the hour-specific phototherapy treatment threshold recommended by the American Academy of Pediatrics in 2004. The compared strategies included those that use (1) a predischarge bilirubin level (obtained before 52 hours) expressed as a risk zone on an hour-specific bilirubin nomogram, (2) clinical risk factors other than the predischarge bilirubin level, and (3) a combination of the predischarge bilirubin risk zone and additional clinical risk factors.

RESULTS

Forty-eight patients (6%) developed significant neonatal hyperbilirubinemia. The predischarge (<52 hours) bilirubin level expressed as a risk zone on the bilirubin nomogram and a prediction model that combined multiple other clinical risk factors had similar accuracy for predicting significant hyperbilirubinemia. The only clinical risk factor that could be added to the predischarge risk zone to improve overall predictive accuracy was gestational age. The predischarge bilirubin risk zone and gestational age could be used to stratify patients into a large group (n = 523 [70%]) of infants with a very low (0.2%) risk of developing significant hyperbilirubinemia, a small group of infants (n = 127 [17%]) with a low (4%) risk of developing significant hyperbilirubinemia, and an even smaller group of infants (n = 100 [13%]) with a high (42%) risk of developing significant hyperbilirubinemia.

CONCLUSIONS

An infant's risk of developing significant hyperbilirubinemia can be simply and accurately assessed by using just the infant's predischarge bilirubin level and gestational age.

Management of jaundice and prevention of severe neonatal hyperbilirubinemia in infants >or=35 weeks gestation

Kernicterus is still occurring but should be largely preventable if health care personnel follow the recommendations listed in this guideline. These recommendations emphasize the importance of universal, systematic assessment of the risk of severe hyperbilirubinemia, lactation support, close follow-up, and prompt intervention when necessary. A systems-based approach to prevent severe neonatal hyperbilirubinemia should be implemented at all birthing facilities and coordinated with continuing ambulatory care. Translational research is needed to better understand the mechanisms of bilirubin neurotoxicity and potential therapeutic interventions.

Neonatal hyperbilirubinemia in African American males: the importance of glucose-6-phosphate dehydrogenase deficiency

OBJECTIVE

To perform risk factor analysis for the prediction of hyperbilirubinemia in an African American male neonatal cohort.

STUDY DESIGN

A database of 500 previously published term and near-term African American male neonates was further analyzed to determine the role of risk factors for hyperbilirubinemia. Factors studied included birth weight >/=4.0 kg, gestational age /=75(th) percentile. Hyperbilirubinemia was defined as any bilirubin value >/=95(th) percentile on the hour-of-life-specific bilirubin nomogram.

RESULTS

Forty-three (8.6%) neonates developed hyperbilirubinemia. At 48 +/- 12 hours, median transcutaneous bilirubin was 8.3 mg/dL, 75(th) percentile 10.0 mg/dL, and 95(th) percentile 12.6 mg/dL. Of the risk factors, only exclusive breast-feeding, G-6-PD deficiency and predischarge bilirubin >/=75(th) percentile were significant (Adjusted Odds Ratios [95% Confidence Intervals; CI] 3.15 [1.39-7.14], P = .006; 4.96 [2.28-10.80], P = .001; and 7.47 [3.50-15.94], P < .0001, respectively). G-6-PD-deficient neonates who were also premature and breast-feeding had the highest incidence of hyperbilirubinemia (60%).

CONCLUSIONS

African American male neonates may be at higher risk for hyperbilirubinemia than previously thought. Screening for G-6-PD deficiency and predischarge bilirubin determination may be useful adjuncts in hyperbilirubinemia prediction in these newborns.

Immunizations, neonatal jaundice and animal-induced injuries

PURPOSE OF REVIEW

To review the literature published within the last year on three topics essential to clinical pediatrics: immunizations, neonatal jaundice, and animal-induced injuries.

RECENT FINDINGS

New vaccines that protect against meningococcus, pertussis and rotavirus are safe, effective and recommended for routine immunization. Young children remain a high priority for influenza vaccination while the world awaits further developments of avian influenza. Pneumococcal and varicella vaccinations have benefited many. Debate exists on how to screen for hyperbilirubinemia in neonates and new strategies are emerging to prevent it. There seems to be no link between hyperbilirubinemia and autism spectrum disorders. We have learned that rabies can be transmitted by transplantation; it remains a global public health problem and its incidence is frequently underestimated in developing nations. Lastly, brown recluse spider bites are often misdiagnosed.

SUMMARY

The face of pediatric infectious disease is changing as we incorporate new vaccines into our routine practice. Rotavirus vaccine has significant implications for the health of children across the globe. The management strategy for neonatal jaundice continues to focus on screening and prevention. We need to devote more energy to combating rabies in countries where it is endemic.

Transcutaneous bilirubin levels in the first 96 hours in a normal newborn population of > or = 35 weeks' gestation

OBJECTIVE

To obtain transcutaneous bilirubin (TcB) measurements, at 6-hour intervals, in the first 96 hours after birth in a normal newborn population (gestational age: > or =35 weeks).

METHODS

We performed 9397 TcB measurements on 3984 healthy newborn infants (gestational age: > or =35 weeks) from 6 to 96 hours of age. All measurements were performed in the well-infant nursery with a Draeger Air-Shields transcutaneous jaundice meter (model JM-103), within 2 hours of the designated time.

RESULTS

There was a distinct pattern to the velocity of the increase in TcB levels over different time periods. TcB levels increased in a linear manner most rapidly in the first 6 to 18 hours and then less rapidly from 18 to 42 hours, followed by a much slower increase until peak levels occurred. Decreasing gestational age was associated significantly with higher TcB levels.

CONCLUSIONS

We provide data on neonatal bilirubinemia, based on TcB levels determined in a large, predominately white and breastfed, North American population. Infants who require closer evaluation and observation initially are those whose bilirubin levels are > or =95th percentile, ie, increasing more rapidly than 0.22 mg/dL per hour in the first 24 hours, 0.15 mg/dL per hour between 24 and 48 hours, and 0.06 mg/dL per hour after 48 hours. These data should be useful for detecting aberrant trends, identifying infants who need additional evaluation, and planning appropriate follow-up for jaundiced newborns.

Kernicterus in late preterm infants cared for as term healthy infants

OBJECTIVE

To compare the clinical profile and health care experiences related to management of newborn jaundice and hyperbilirubinemia in preterm infants (<37(0/7) weeks gestation) who are cared for as term infants (> or =37(0/7) weeks) and develop acute and/or chronic posticteric sequelae.

METHODS

Retrospective study of a convenient sample of term and near term infants voluntarily reported to the Pilot Kernicterus Registry (1992-2003). Study infants were required to meet the clinical definitions for acute bilirubin encephalopathy (moderate or advanced severity) and/or the classical signs of kernicterus. Main outcome measures were the comparison of etiology, severity and duration of extreme hyperbilirubinemia (TSB levels >20 mg/dL), response to interventions of intensive phototherapy and exchange transfusion, and health care delivery experiences in preterm as compared with term infants.

RESULTS

No targeted attention was accorded to preterm infants during their neonatal health care experiences as related to predischarge risk assessment, feeding, discharge follow-up instructions, or breastfeeding, regardless of the known vulnerability of preterm infants to safely transition during the first week after birth. The TSB levels, age at re-hospitalization, and birth weight distribution were similar for late preterm and term infants. Large for gestational age and late preterm infants disproportionately developed kernicterus as compared with those who were appropriate for gestational age and term. Clinical management of extreme of hyperbilirubinemia, by the attending clinical providers, was not impacted or influenced by the gestational age, clinical signs, or risk assessment. This resulted in severe posticteric sequelae which was more severe and frequent in late preterm infants.

CONCLUSIONS

Late prematurity (34(0/7) to 36(6/7) weeks) of healthy infants was not recognized as a risk factor for hazardous hyperbilirubinemia by clinical practitioners. Unsuccessful lactation experience was the most frequent experience; being large for gestational age as well as the other known biologic risk factors for hyperbilirubinemia and bilirubin neurotoxicity were not identified by the clinical care providers either before discharge or at immediate postdischarge follow up.