Vigintiphobia revisited

A decision-making tool for exchange transfusions in infants with severe hyperbilirubinemia in resource-limited settings

Late presentation and ineffective phototherapy account for excessive rates of avoidable exchange transfusions (ETs) in many low- and middle-income countries. Several system-based constraints sometimes limit the ability to provide timely ETs for all infants at risk of kernicterus, thus necessitating a treatment triage to optimize available resources. This article proposes a practical priority-setting model for term and near-term infants requiring ET after the first 48 h of life. The proposed model combines plasma/serum bilirubin estimation, clinical signs of acute bilirubin encephalopathy and neurotoxicity risk factors for predicting the risk of kernicterus based on available evidence in the literature.

Common hematologic problems in the newborn nursery

"Common red blood cell disorders encountered in the normal newborn nursery include hemolytic disease of the newborn and resultant hyperbilirubinemia, anemia, and polycythemia. A less frequent clinically relevant hematologic issue in newborns to be covered herein is thrombocytopenia."

Glucose-6-phosphate-dehydrogenase deficiency and its correlation with other risk factors in jaundiced newborns in Southern Brazil

OBJECTIVE

To evaluate the correlation between glucose-6-phosphate-dehydrogenase (G6PD) deficiency and neonatal jaundice.

METHODS

Prospective, observational case-control study was conducted on 490 newborns admitted to Hospital de Clínicas de Porto Alegre for phototherapy, who all experienced 35 or more weeks of gestation, from March to December 2007. Enzymatic screening of G6PD activity was performed, followed by PCR.

RESULTS

There was prevalence of 4.6% and a boy-girl ratio of 3:1 in jaundiced newborns. No jaundiced neonate with ABO incompatibility presented G6PD deficiency, and no Mediterranean mutation was found. A higher proportion of deficiency was observed in Afro-descendants. There was no association with UGT1A1 variants.

CONCLUSIONS

G6PD deficiency is not related to severe hyperbilirubinemia and considering the high miscegenation in this area of Brazil, other gene interactions should be investigated.

Bilirubin-albumin binding, bilirubin/albumin ratios, and free bilirubin levels: where do we stand?

Treatment for unconjugated hyperbilirubinemia is predominantly based on one parameter, i.e., total serum bilirubin (TSB) levels. Yet, overt kernicterus has been reported in preterm infants at relatively low TSB levels, and it has been repeatedly shown that free unconjugated bilirubin (freeUCB) levels, or bilirubin/albumin (B/A) ratios for that matter, are more closely associated with bilirubin neurotoxicity. In this article, we review bilirubin-albumin binding, UCBfree levels, and B/A ratios in addition to TSB levels to individualize and optimize treatment especially in preterm infants. Methods to measure bilirubin-albumin binding or UCBfree are neither routinely performed in Western clinical laboratories nor incorporated in current management guidelines on unconjugated hyperbilirubinemia. For bilirubin-albumin binding, this seems justified because several of these methods have been challenged, and sufficiently powered prospective trials on the clinical benefits are lacking. Technological advances in the measurement of UCBfree may provide a convenient means for integrating UCBfree measurements into routine clinical management of jaundiced infants. A point-of-care method, as well as determination of UCBfree levels in various newborn populations, is desirable to learn more about variations in time and how various clinical pathophysiological conditions affect UCBfree levels. This will improve the estimation of approximate UCBfree levels associated with neurotoxicity. To delineate the role of UCBfree in the management of jaundiced (preterm) infants, trials are needed using UCBfree as treatment parameter. The additional use of the B/A ratio in jaundiced preterms has been evaluated in the Bilirubin Albumin Ratio Trial (BARTrial; Clinical Trials: ISRCTN74465643) but failed to demonstrate better neurodevelopmental outcome in preterm infants <32 weeks assigned to the study group. Awaiting a study in which infants are assigned to be managed solely on the basis of their B/A ratio (with TSB excluded ) versus TSB levels alone-and determining which group does better-the additional use of the B/A ratio in the management of hyperbilirubinemia in preterms is not advised. In conjunction with TSB levels, other parameters possibly allow for more accurate prediction of bilirubin toxicity. Yet, different methodologies for estimating these parameters exist, and sufficiently powered, prospective clinical trials supporting their clinical benefit, i.e., reduced bilirubin neurotoxicity when using these parameters, are lacking. Their use in addition to TSB needs to be prospectively evaluated, especially in preterm neonates, and preferentially in randomized clinical trials, which include specific risk factors and assessment of clinical relevant outcome measures for detecting those infants at risk of bilirubin toxicity.

Outcome of exchange blood transfusions done for neonatal jaundice in abakaliki, South eastern Nigeria

Background:

Neonatal jaundice (NNJ) is a major cause of morbidity and mortality among neonates in Nigeria and exchange blood transfusion (EBT) is a common modality of its treatment in Ebonyi State University Teaching Hospital (EBSUTH), Abakaliki. This communication aims to audit this service.

Materials and Methods:

A 3-year retrospective review of the case files of all neonates that had EBT for NNJ at the new born special care unit of EBSUTH.

Result:

Two hundred and thirty seven (17.25%) out of 1374 neonatal admissions had NNJ. EBT was performed for 40 (16.9%) of them. The commonest indications for EBT were low birth weight/prematurity, ABO blood group incompatibility, sepsis and glucose 6 phosphate deficiencies. The mean serum bilirubin at which EBT was done was 28.3 mg/dl. The EBT was uneventful in 36 cases while in four (10%) cases there were reported adverse events. Seven neonates (17.5%) died after the procedure and documented causes of death include bilirubin encephalopathy, respiratory failure, and septic shock and disseminated intravascular coagulopathy.

Conclusion:

There is high rate of EBT use in the management of severe neonatal hyperbilirubinemia with significant morbidity and mortality in this study site. There is need to review the contribution of factors such as late presentation in the hospital to this and proffer solutions to it.

Usefulness of (1) H-MRS in differentiating bilirubin encephalopathy from severe hyperbilirubinemia in neonates

PURPOSE

To evaluate the usefulness of (1) H-MRS in differentiating bilirubin encephalopathy from severe hyperbilirubinemia in neonates.

MATERIALS AND METHODS

There were 11 patients enrolled in the neonatal bilirubin encephalopathy (NBE) group, 8 patients in the neonatal hyperbilirubinemia (NH) group, and 9 healthy, age-matched neonates were included as controls. All patients and controls underwent (1) H-MRS and conventional magnetic resonance (MR) sequences. The spectroscopic regions of interest were the bilateral basal ganglia and the thalamus, and a spatial resolution of 1.0 cm(3) was obtained.

RESULTS

Peak-area ratios of NAA/Cr and NAA/ Cho in the basal ganglia were found to be significantly lower for the NBE group compared with the NH and control groups (P < 0.05). In contrast, there was no significant difference in the NAA/Cr ratios calculated for basal ganglia of the NH and control groups. Peak-area ratios of NAA/Cr and NAA/Cho in the thalamus were decreased for the NBE group compared with the NH and control groups, but the differences were not significant (P > 0.05). There was a significant correlation between NAA/Cr ratios for basal ganglia and the total serum bilirubin (TSB) peak level in the NBE group (P < 0.05).

CONCLUSION

(1) H-MRS is useful in the differential diagnosis of NBE from severe hyperbilirubinemia in neonates, especially when the symptoms of NBE are atypical (subtle) and MRI does not reveal clear abnormalities.

Guidelines for detection, management and prevention of hyperbilirubinemia in term and late preterm newborn infants (35 or more weeks' gestation) - Summary

Hyperbilirubinemia is very common and usually benign in the term newborn infant and the late preterm infant at 35 and 36 completed weeks' gestation. Critical hyperbilirubinemia is uncommon but has the potential for causing long-term neurological impairment. Early discharge of the healthy newborn infant, particularly those in whom breastfeeding may not be fully established, may be associated with delayed diagnosis of significant hyperbilirubinemia. Guidelines for the prediction, prevention, identification, monitoring and treatment of severe hyperbilirubinemia are presented.

Risk of hyperbilirubinemia in breast-fed infants

OBJECTIVE

To investigate the risk factors for hyperbilirubinemia in infants who are exclusively breast-fed.

STUDY DESIGN

A prospective study was conducted to investigate the effects of birth body weight, sex, mode of delivery, glucose-6-phosphate dehydrogenase (G6PD) deficiency, variant UDP-glucuronosyltransferase 1A1 (UGT1A1) gene, and hepatic solute carrier organic anion transporter 1B1 (SLCO1B1) gene on hyperbilirubinemia in neonates who were breast-fed. Hyperbilirubinemia was diagnosed when a full term neonate had a bilirubin level ≧15.0 mg/dL (256.5 μM) in serum at 3 days old. The polymerase chain reaction-restriction fragment length polymorphism method was used as a means of detecting the known variant sites in the UGT1A1 and SLCO1B1 gene.

RESULTS

Of 252 infants born at term who were exclusively breast-fed, 59 (23.4%) had hyperbilirubinemia. The significant risk factors were a variant nucleotide 211 in UGT1A1 (2.48; 95% CI, 1.29 to 4.76; P = .006), G6PD deficiency (12.24; 95% CI, 1.08 to 138.62; P < .05), and vaginal delivery (3.55; 95% CI, 1.64 to 7.66; P < .001).

CONCLUSION

Breast-fed neonates who are 211 variants in the UGT1A1, G6PD deficiency, and vaginal delivery are at high-risk for hyperbilirubinemia.

National guidelines for treatment of jaundice in the newborn

Jaundice is the most common reason for instituting treatment in otherwise healthy as well as sick newborn infants. Herein, we describe the process employed in Norway to forge agreement on a set of treatment guidelines that are now used across the country. The Norwegian Pediatric Association was a key resource in this process, which involved contacts with all paediatric departments in Norway. We have also performed an international survey regarding the use of such national guidelines, showing that the majority of those queried confirm having national guidelines. The evidence base for any neonatal jaundice guideline is weak; therefore, it is not surprising that the various guidelines differ both in format and in specifics. In the Norwegian guidelines, treatment indications are based on bilirubin concentrations and related to birth weight. Postnatal age is also factored in because jaundice develops gradually during the first 3-4 days before it levels off.

CONCLUSION

Following the introduction of these guidelines, fewer babies in Norway receive phototherapy, and no cases of chronic kernicterus have been reported during this period.

Clinical and genetic risk factors for moderate hyperbilirubinemia in Brazilian newborn infants

OBJECTIVE

To identify clinical and genetic risk factors for moderate hyperbilirubinemia during the first week of life.

STUDY DESIGN

Using univariate and multivariate multiple regression analyses, the RR for clinical factors, the African variant of glucose-6-phosphate dehydrogenase (G6PD) deficiency (G202A/A376G), and (TA)(n) UGT1A1 polymorphisms were established in a cohort of 608 Brazilian newborn infants. Hyperbilirubinemia was monitored until 134.5 ± 49.8 h of life (IQR, 111.0 to 156.7). The dependent variable was total bilirubinemia (TB) ≥12.9 mg per 100 ml estimated by transcutaneous or plasma bilirubin measurements.

RESULT

The African variant of G6PD deficiency and (TA)(7)/(TA)(7) and (TA)(7)/(TA)(8) polymorphisms present in 6.1 and 12.0% of newborns, respectively, were not risk factors for moderate hyperbilirubinemia. Coexpression of G6DP deficiency and UGT1A1 polymorphisms occurred in 0.49% of the subjects. Independent clinical predictors for TB≥ 12.9 mg per 100 ml were gestational age <38 weeks and reference curve percentiles >P40th.

CONCLUSION

In this study, G6PD deficiency and UGT1A1 gene promoter polymorphisms were not risk factors for moderate hyperbilirubinemia. Genetic factors may vary considerably in importance among different populations.

Exploring the genetic architecture of neonatal hyperbilirubinemia

The potential for genetic variation to modulate neonatal hyperbilirubinemia risk is increasingly being recognized. In particular, polymorphisms across three genes involved in bilirubin production and metabolism [glucose-6-phosphate dehydrogenase (G6PD), uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1), and solute carrier organic anion transporter polypeptide 1B1 (SLCO1B1)] may interact with each other and/or environmental contributors to produce significant hyperbilirubinemia. Variant gene co-expression including compound and synergistic heterozygosity enhances hyperbilirubinemia risk, contributing to the etiologic heterogeneity and complex nature of neonatal jaundice.

Managing well-appearing neonates with hyperbilirubinemia in the emergency department observation unit

BACKGROUND

In September 2005, Texas Children's Hospital initiated a protocol for all neonates presenting to the emergency department (ED) with hyperbilirubinemia based on the American Academy of Pediatrics guidelines. As part of the protocol, low-risk neonates with hyperbilirubinemia requiring phototherapy are treated in the ED observation unit (EDOU).

OBJECTIVE

The aim of the study was to compare time to phototherapy and duration of hospital stay in low-risk neonates with hyperbilirubinemia presenting to the Texas Children's Hospital ED before and after the initiation of a triage-based protocol.

DESIGN/METHODS

We performed a retrospective historical control study comparing neonates with hyperbilirubinemia treated in the EDOU between January 1 and December 31, 2006 (EDOU group), with neonates with hyperbilirubinemia admitted to the inpatient unit between January 1 and December 31, 2004 (inpatient group).

RESULTS

There were 167 neonates included in the study: 62 neonates were treated in the EDOU and 105 in the inpatient unit. Median time to phototherapy (inpatient: 6.7 hours, EDOU: 1.6 hours) and duration of hospital stay (inpatient: 41.8 hours, EDOU: 17.8 hours) were shorter for neonates treated in the EDOU compared with neonates treated in the inpatient unit. Of the neonates treated in the EDOU initially, 11 were admitted to the inpatient unit after 24 hours because their bilirubin level did not decline adequately.

CONCLUSIONS

Low-risk neonates with hyperbilirubinemia can be managed more efficiently in an EDOU than in an inpatient unit. Phototherapy is initiated more rapidly, and patients are discharged sooner in the EDOU than in the inpatient setting.

Clinical characteristics of G6PD deficiency in infants with marked hyperbilirubinemia

This study analyzes the clinical features of glucose-6-phosphate dehydrogenase (G6PD) deficiency in infants with marked hyperbilirubinemia. We retrospectively assessed a cohort of 413 infants with peak total serum bilirubin (TSB) level >or=20 mg/dL from 1995 to 2007. The prevalence of G6PD deficiency was proportional to the level of peak TSB: 21.1% (81/383) in 20 mg/dL to 29.9 mg/dL, 45.5% (10/22) in 30 mg/dL to 39.9 mg/dL, and 100% (8/8) in >or=40 mg/dL. Male sex was more common in G6PD deficiency (75.8%). When compared with G6PD-normal infants, those with G6PD deficiency tended to have extreme hyperbilirubinemia (peak TSB level >or=25 mg/dL) and hemoglobin value<13 g/dL (P<0.001). Furthermore, mortality rate was significantly higher in G6PD-deficient infants (3.0%) than in the G6PD-normal counterparts (0.0%). Among 58 of the G6PD-deficient infants who were followed for more than 12 months, 4 developed the classic neurologic manifestations of kernicterus (6.6%). These findings show that G6PD deficiency is an important risk factor of extreme hyperbilirubinemia, death, and kernicterus.

Impact of universal bilirubin screening on severe hyperbilirubinemia and phototherapy use

OBJECTIVE

The goal was to assess the impact of universal bilirubin screening on severe hyperbilirubinemia and phototherapy use.

METHODS

In this retrospective cohort study of 358086 infants of > or =35 weeks and > or =2000 g born between January 1, 1995, and June 30, 2007, we obtained demographic data, bilirubin levels, and codes for inpatient phototherapy from existing databases. We compared the incidence of high total serum bilirubin (TSB) levels and phototherapy before and after implementation of universal screening and examined risk factors for high TSB levels.

RESULTS

A total of 38182 infants (10.6%) were born at facilities that had implemented universal bilirubin screening. Compared with infants born at facilities that were not screening, these infants had a 62% lower incidence of TSB levels exceeding the American Academy of Pediatrics exchange guideline (0.17% vs 0.45%; P < .001), received twice the inpatient phototherapy (9.1% vs 4.2%; P < .001), and had slightly longer birth hospitalization lengths of stay (50.9 vs 48.7 hours; P < .001). Of those receiving phototherapy, 56% after initiation of universal screening had TSB levels at which phototherapy was recommended by the guideline, compared with 70% before screening. The adjusted odds ratio for developing TSB levels exceeding the guideline value was 0.28 (95% confidence interval: 0.20-0.40) for those born at a facility using TSB screening and 0.28 (95% confidence interval: 0.19-0.42) for those born at a facility using transcutaneous bilirubin screening.

CONCLUSIONS

Universal bilirubin screening was associated with a significantly lower incidence of severe hyperbilirubinemia but also with increased phototherapy use.

Identification of neonates at risk for hazardous hyperbilirubinemia: emerging clinical insights

Hyperbilirubinemia is the most common condition requiring evaluation and treatment in neonates. Identifying among all newborns those few at risk to develop marked hyperbilirubinemia is a clinical challenge. Clinical, epidemiologic, and genetic risk factors associated with severe hyperbilirubinemia include late preterm gestational age, exclusive breastfeeding, glucose-6-phosphate dehydrogenase deficiency, ABO hemolytic disease, East Asian ethnicity, jaundice observed in the first 24 hours of life, cephalohematoma or significant bruising, and history of a previous sibling treated with phototherapy. It is increasingly apparent that the etiopathogenesis of severe hyperbilirubinemia is often multifactorial, and emerging evidence suggests that combining risk factor assessment with measurement of predischarge total serum or transcutaneous bilirubin levels will improve hyperbilirubinemia risk prediction.

Why we are still doing so many exchange blood transfusion for neonatal jaundice in Nigeria

BACKGROUND

Since exchange blood transfusion (EBT) is associated with serious complications, phototherapy has been made more powerful to reduce the need for EBT in the developed world. This study was undertaken to determine the indications for EBT in neonatal jaundice (NNJ) at our unit and what proportion of EBTs was possibly avoidable.

METHODS

All the babies who had EBT for hyperbilirubinemia over a three-year period were included. Age, sex, weight, place of delivery, blood group of baby and mother, other investigations, management, and the outcome of the babies were recorded.

RESULTS

Of the 1686 babies admitted to the neonatal unit, 90 (5.3%) had EBT. Fourteen (15.6%) were inborn while 76 (84.4%) were out-born babies. Fifty-six (62.2%) babies were admitted primarily for NNJ while 34 (37.8%) developed NNJ during admission. Thirty-six (40.0%) of the babies had phototherapy for more than 24 hours prior to EBT either because they were of very low birthweight or NNJ was detected very early and therapy was so commenced. Sixty-eight (75.6%) babies had single EBT while the remaining 22 (24.4%) had two sessions of EBT. Factors associated with severe NNJ in babies requiring EBT included low birthweight (<2500 g, 44.4%), ABO incompatibility (30.0%), glucose-6-phosphate dehydrogenase deficiency (34.4%) and septicemia (26.1%). Twenty-seven (30.0%) of the neonates developed features of kernicterus: 26 before admission while 1 during admission; all except one were delivered outside the hospital.

CONCLUSIONS

The EBT rate in our center was high. With more effective phototherapy, EBT could be avoided in most of the babies who initially had phototherapy for more than 24 hours before EBT and repeated EBT sessions. Health education of the population at risk, especially pregnant women, and early referral at the primary health care level will reduce the burden of severe NNJ.

Coexpression of gene polymorphisms involved in bilirubin production and metabolism

OBJECTIVE

The potential for genetically determined conditions to modulate the risk for developing neonatal hyperbilirubinemia is increasingly being recognized. The aims of this investigation were to (1) develop genotyping assays for an expanded panel of mutations and polymorphisms across 3 genes that are involved in bilirubin production and metabolism (glucose-6-phosphate dehydrogenase [G6PD], uridine diphosphate glucuronosyl transferase 1A1 [UGT1A1], and organic anion transporter polypeptide 1B1 [OATP1B1]) and (2) determine their allele frequencies in 450 anonymous DNA samples of US residents with ancestry from all of the major regions of the world.

METHODS

Genotyping assays were developed on the basis of allele-specific hybridization and melting peak analysis of the probe set and the match or mismatch template. Allele frequencies and the complexity of coinheritance of multiple genetic variants across G6PD, UGT1A1, and OATP1B1 genes in DNA samples from the DNA Polymorphism Discovery Resource of the National Human Genome Research Institute were determined by using this expanded panel.

RESULTS

Genetic polymorphisms of the UGT1A1 promoter, specifically the T-3279G phenobarbital responsive enhancer module and the (thymidine-adenine)(7) dinucleotide repeat TATAA box variants, were common. Similarly, OATP1B1 coding sequence gene variants were frequently observed. Moreover, in more than three quarters of the samples, >or=2 variants were detected, reflecting a high degree of polymorphism coexpression across these genes, including those who carried the African A(-) G6PD mutation.

CONCLUSIONS

We conclude that this expanded panel of mutations and polymorphisms can serve as an effective instrument to study the genetic architecture of hyperbilirubinemia and speculate an important role for genetic polymorphism coinheritance in determining hyperbilirubinemia risk in newborns.

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.

A decline in the frequency of neonatal exchange transfusions and its effect on exchange-related morbidity and mortality

OBJECTIVE

Our goal was to identify trends in patient demographics and indications for and complications related to neonatal exchange transfusion over a 21-year period in a single institution using a uniform protocol for performing the procedure.

METHODS

A retrospective chart review of 107 patients who underwent 141 single- or double-volume exchange transfusions from 1986-2006 was performed. Patients were stratified into 2 groups, 1986-1995 and 1996-2006, on the basis of changes in clinical practice influenced by American Academy of Pediatrics management guidelines for hyperbilirubinemia.

RESULTS

There was a marked decline in the frequency of exchange transfusions per 1000 newborn special care unit admissions over the 21-year study period. Patient demographics and indications for exchange transfusion were similar between groups. A significantly higher proportion of patients in the second time period received intravenous immunoglobulin before exchange transfusion. There was a higher proportion of patients in the 1996-2006 group with a serious underlying condition at the time of exchange transfusion. During that same time period, a lower proportion of patients experienced an adverse event related to the exchange transfusion. Although a similar percentage of patients in both groups experienced hypocalcemia and thrombocytopenia after exchange transfusion, patients treated from 1996-2006 were significantly more likely to receive calcium replacement or platelet transfusion. No deaths were related to exchange transfusion in either time period.

CONCLUSIONS

Improvements in prenatal and postnatal care have led to a sharp decline in the number of exchange transfusions performed. This decline has not led to an increase in complications despite relative inexperience with the procedure.

Hyperbilirubinemia and bilirubin toxicity in the late preterm infant

Late preterm gestation is an important risk factor for the development of severe neonatal hyperbilirubinemia and kernicterus. An exaggerated hepatic immaturity contributes to the greater prevalence, severity, and duration of neonatal jaundice in late preterm infants. Breast milk feeding is almost uniformly present and large for gestational age status, male sex, and G6PD deficiency are over-represented among that cohort of late preterm infants with kernicterus. Attention to screening measures for jaundice in the newborn nursery, the provision of lactation support, parental education, timely postdischarge follow-up, and appropriate treatment when clinically indicated should help to reduce the risk of late preterm neonates developing severe neonatal jaundice or kernicterus.

Outcomes among newborns with total serum bilirubin levels of 25 mg per deciliter or more

BACKGROUND

The neurodevelopmental risks associated with high total serum bilirubin levels in newborns are not well defined.

METHODS

We identified 140 infants with neonatal total serum bilirubin levels of at least 25 mg per deciliter (428 micromol per liter) and 419 randomly selected controls from a cohort of 106,627 term and near-term infants born from 1995 through 1998 in Kaiser Permanente hospitals in northern California. Data on outcomes were obtained from electronic records, interviews, responses to questionnaires, and neurodevelopmental evaluations that had been performed in a blinded fashion.

RESULTS

Peak bilirubin levels were between 25 and 29.9 mg per deciliter (511 micromol per liter) in 130 of the newborns with hyperbilirubinemia and 30 mg per deciliter (513 micromol per liter) or more in 10 newborns; treatment involved phototherapy in 136 cases and exchange transfusion in 5. Follow-up data to the age of at least two years were available for 132 of 140 children with a history of hyperbilirubinemia (94 percent) and 372 of 419 controls (89 percent) and included formal evaluation at a mean (+/-SD) age of 5.1+/-0.12 years for 82 children (59 percent) and 168 children (40 percent), respectively. There were no cases of kernicterus. Neither crude nor adjusted scores on cognitive tests differed significantly between the two groups; on most tests, 95 percent confidence intervals excluded a 3-point (0.2 SD) decrease in adjusted scores in the hyperbilirubinemia group. There was no significant difference between groups in the proportion of children with abnormal neurologic findings on physical examination or with documented diagnoses of neurologic abnormalities. Fourteen of the children with hyperbilirubinemia (17 percent) had "questionable" or abnormal findings on neurologic examination, as compared with 48 controls (29 percent; P=0.05; adjusted odds ratio, 0.47; 95 percent confidence interval, 0.23 to 0.98; P=0.04). The frequencies of parental concern and reported behavioral problems also were not significantly different between the two groups. Within the hyperbilirubinemia group, those with positive direct antiglobulin tests had lower scores on cognitive testing but not more neurologic or behavioral problems.

CONCLUSIONS

When treated with phototherapy or exchange transfusion, total serum bilirubin levels in the range included in this study were not associated with adverse neurodevelopmental outcomes in infants born at or near term.