Interaction of hemolysis and hyperbilirubinemia on neurodevelopmental outcomes in the collaborative perinatal project

Long-term neurocognitive and educational outcomes of neonatal insults in Kilifi, Kenya

BACKGROUND

There is little data on the long-term neurocognitive and educational outcomes among school-aged survivors of neonatal jaundice (NNJ) and hypoxic-ischemic encephalopathy (HIE) in Africa. This study investigates the long-term neurocognitive and educational outcomes and the correlates of these outcomes in school-aged survivors of NNJ or HIE in Kilifi, Kenya.

METHODS

We conducted a cross-sectional study on neurocognitive and educational outcomes among school-aged survivors (6-12 years) of NNJ (n = 134) and HIE (n = 107) and compared them to a community comparison group (n = 134). We assessed nonverbal intelligence, planning, working memory, attention, syntax, pragmatics, word-finding, memory, perceptual-motor, mathematical, and reading abilities. We also collected information on medical history, caregivers' mental health, and family environment.

RESULTS

The survivors of NNJ had lower mean total scores in word-finding [F (1, 250) = 3.89, p = 0.050] and memory [F (1, 248) = 6.74, p = 0.010] than the comparison group. The survivors of HIE had lower mean scores in pragmatics [F (1, 230) = 6.61, p = 0.011] and higher scores higher scores in non-verbal reasoning [F (1, 225) =4.10, p = 0.044] than the comparison group. Stunted growth was associated with almost all the outcomes in HIE.

CONCLUSION

Survivors of NNJ and HIE present with impairment in the multiple domains, which need to be taken into consideration in the planning of educational and rehabilitative services.

Long-term outcomes of survivors of neonatal insults: A systematic review and meta-analysis

BACKGROUND

The Millennium Developmental Goals ensured a significant reduction in childhood mortality. However, this reduction simultaneously raised concerns about the long-term outcomes of survivors of early childhood insults. This systematic review focuses on the long-term neurocognitive and mental health outcomes of neonatal insults (NNI) survivors who are six years or older.

METHODS

Two independent reviewers conducted a comprehensive search for empirical literature by combining index and free terms from the inception of the databases until 10th October 2019. We also searched for additional relevant literature from grey literature and using reference tracking. Studies were included if they: were empirical studies conducted in humans; the study participants were followed at six years of age or longer; have an explicit diagnosis of NNI, and explicitly define the outcome and impairment. Medians and interquartile range (IQR) of the proportions of survivors of the different NNI with any impairment were calculated. A random-effect model was used to explore the estimates accounted for by each impairment domain.

RESULTS

Fifty-two studies with 94,978 participants who survived NNI were included in this systematic review. The overall prevalence of impairment in the survivors of NNI was 10.0% (95% CI 9.8-10.2). The highest prevalence of impairment was accounted for by congenital rubella (38.8%: 95% CI 18.8-60.9), congenital cytomegalovirus (23.6%: 95% CI 9.5-41.5), and hypoxic-ischemic encephalopathy (23.3%: 95% CI 14.7-33.1) while neonatal jaundice has the lowest proportion (8.6%: 95% CI 2.7-17.3). The most affected domain was the neurodevelopmental domain (16.6%: 95% CI 13.6-19.8). The frequency of impairment was highest for neurodevelopmental impairment [22.0% (IQR = 9.2-24.8)] and least for school problems [0.0% (IQR = 0.0-0.00)] in any of the conditions.

CONCLUSION

The long-term impact of NNI is also experienced in survivors of NNI who are 6 years or older, with impairments mostly experienced in the neurodevelopmental domain. However, there are limited studies on long-term outcomes of NNI in sub-Saharan Africa despite the high burden of NNI in the region.

TRIAL REGISTRATION

Registration number: CRD42018082119.

Patterns of neurobehavioral functioning in school-aged survivors of neonatal jaundice and hypoxic-ischemic encephalopathy in Kilifi, Kenya: A cross-sectional study

Background: Studies in high-income countries have reported that school-aged children who survive neonatal jaundice (NNJ) and hypoxic-ischemic encephalopathy (HIE) develop long-term neurocognitive problems. However, less is known about the patterns of functioning in school-aged survivors of NNJ and HIE in sub-Saharan Africa. This study examined patterns of functioning in school-aged children who survived NNJ and HIE in Kilifi, Kenya. Methods: This is a cross-sectional study that included 107 survivors of NNJ/HIE (64 with NNJ, 43 with HIE), aged 6-12 years, admitted to Kilifi County Hospital on the Kenyan Coast. The Gross Motor Function Classification System (GMFCS), Adapted Communication Profile, Raven’s Coloured Progressive Matrices (RCPM) and an epilepsy screening tool were used to assess gross motor function, communication function, intellectual functioning, and epilepsy, respectively. Results: Most of the survivors of NNJ (95.2%) and HIE (95.3%) had no impairments in gross motor functioning. A small percentage of the children in the NNJ and HIE groups had profound problems in their communication (4.7% and 4.7%); expressive communication function (4.7% and 4.7%); social functions (3.1% and 2.3%); receptive communication (4.7% and 2.3%); and communicative effectiveness (4.7% and 2.3%). Cognitive impairment was reported in 10.9% and 11.9% for NNJ and HIE survivors, respectively. Active epilepsy was detected in 1.6% of survivors of NNJ and 2.3% of survivors of HIE. All children had normal hearing and visual functioning except one participant who presented with mild visual acuity problems. Conclusions: Most school-aged children who survive with NNJ and HIE have normal motor and communication function; however, one in ten are likely to present with lowered intellectual functioning compared to the normative sample.

Noninvasive Detection of Hemolysis with ETCOc Measurement in Neonates at Risk for Significant Hyperbilirubinemia

BACKGROUND

Hemolytic hyperbilirubinemia due to blood group incompatibility or glucose-6-phosphate dehydrogenase deficiency (G6PD) is a common cause of significant hyperbilirubinemia. Hemolysis in a hyperbilirubinemic infant increases the risk of bilirubin neurotoxicity. A new portable device (CoSense) can rapidly detect breath end-tidal carbon monoxide corrected to ambient carbon monoxide (ETCOc). ETCOc levels are surrogate markers of hemoglobin breakdown and bilirubin production.

OBJECTIVE

The aim was to evaluate the association between ETCOc values and hemolysis and its relevance in neonates at risk for significant hyperbilirubinemia.

METHODS

A prospective study was conducted among newborn infants born at more than 35 weeks and with a birth weight greater than 2,000 g with a G6PD deficiency, blood group incompatibility, or clinical jaundice needing phototherapy during the first 7 days of life. The recruited infants had their breath ETCOc measured twice, first on the day of recruitment and then again on the following day.

RESULTS

Fifty infants completed this study. Their mean ETCOc was 1.61 (±0.56) ppm. There was a linear correlation (r = 0.89) between increasing ETCOc values and reticulocyte counts (RC). Sixteen newborns with ABO incompatibility had a significantly higher mean ETCOc of 1.98 ppm (±0.71) as compared to 1.43 (±0.38) ppm in the nonhemolytic hyperbilirubinemia (NHH) group (n = 25) (p = 0.002). This was suggestive of hemolysis as shown by the significantly higher RC of 6.90% (±3.38) compared to 4.68 (±1.26) in the NHH group (p <0.005). Neonates with an ETCOc level ≥1.8 ppm had a higher RC, a lower hemoglobin level, higher serum bilirubin levels, and a rapid rise in serum bilirubin and needed a longer duration of phototherapy. ETCOc values ≥1.8 ppm were suggestive of hemolysis (RC ≥6%), with a sensitivity of 90% and a specificity of 83%.

CONCLUSION

Higher ETCOc values ≥1.8 ppm are suggestive of hemolysis and they are associated with significant hyperbilirubinemia.

Patterns of neurobehavioral functioning in school-aged survivors of neonatal jaundice and hypoxic-ischemic encephalopathy in Kilifi, Kenya: A cross-sectional study

Background: Studies in high-income countries have reported that school-aged children who survive neonatal jaundice (NNJ) and hypoxic-ischemic encephalopathy (HIE) develop long-term neurocognitive problems. However, less is known about the patterns of functioning in school-aged survivors of NNJ and HIE in sub-Saharan Africa. This study examined patterns of functioning in school-aged children who survived NNJ and HIE in Kilifi, Kenya. Methods: This is a cross-sectional study that included 107 survivors of NNJ/HIE (64 with NNJ, 43 with HIE), aged 6-12 years, admitted to Kilifi County Hospital on the Kenyan Coast. The Gross Motor Function Classification System (GMFCS), Adapted Communication Profile, Raven’s Coloured Progressive Matrices (RCPM) and an epilepsy screening tool were used to assess gross motor function, communication function, intellectual functioning, and epilepsy, respectively. Results: Most of the survivors of NNJ (95.2%) and HIE (95.3%) had no impairments in gross motor functioning. A small percentage of the children in the NNJ and HIE groups had profound problems in their communication (4.7% and 4.7%); expressive communication function (4.7% and 4.7%); social functions (3.1% and 2.3%); receptive communication (4.7% and 2.3%); and communicative effectiveness (4.7% and 2.3%). Cognitive impairment was reported in 10.9% and 11.9% for NNJ and HIE survivors, respectively. Active epilepsy was detected in 1.6% of survivors of NNJ and 2.3% of survivors of HIE. All children had normal hearing and visual functioning except one participant who presented with mild visual acuity problems. Conclusions: Most school-aged children who survive with NNJ and HIE have normal motor and communication function; however, one in ten are likely to present with lowered intellectual functioning compared to the normative sample.

Developmental influence of unconjugated hyperbilirubinemia and neurobehavioral disorders

Bilirubin-induced brain injury in the neonatal period has detrimental effects on neurodevelopment that persist into childhood and adulthood, contributing to childhood developmental disorders. Unconjugated bilirubin is a potent antioxidant that may be useful for protecting against oxidative injuries, but it becomes a potent neurotoxin once it crosses the blood brain barrier. Because bilirubin toxicity involves a myriad of pathological mechanisms, can damage most types of brain cells, and affects brain circuits or loops that influence cognition, learning, behavior, sensory, and language, the clinical effects of bilirubin-induced neurotoxicity are likely to be manifold. One possible effect that several experts have identified is bilirubin-induced neurological dysfunction (subtle kernicterus). However, the underlying biological mechanisms or pathways by which subtle kernicterus could lead to developmental disorders has not been elucidated previously. Our aim in this review is to describe a spectrum of developmental disorders that may reflect subtle kernicterus and outline plausible biological mechanisms for this possible association. We review existing evidence that support or refute the association between unconjugated hyperbilirubinemia and developmental disorders, and limitations associated with these studies.

Follow-up of Children with Kernicterus in Kano, Nigeria

INTRODUCTION

Acute bilirubin encephalopathy (ABE) is associated with long-term sequelae (kernicterus). It continues to be a significant issue in our region of Nigeria, accounting for much morbidity and mortality. Herein we report the outcome of neonates with ABE seen at our centre.

METHODOLOGY

We established a surveillance of children who had ABE and returned to follow-up from prospective cases of ABE (2012-2014). ABE was diagnosed based on a bilirubin-induced neurologic dysfunction score of ≥ 1. Kernicterus was subsequently established based on a history of developmental delays, hearing impairments and abnormal physical and neurologic examinations at follow-up age ≥3 months.

RESULT

Five hundred fifty-one neonates had hyperbilirubinaemia of whom 104 (18.8%) had ABE. Mean transcutaneous bilirubin using the Ingram icterometer was 18.3 mg/dl  ±  SD 1.9 [(12.5-19.1), total serum bilirubin of 18.1 ± 10.9] (range: 10.3-64 mg/dl). Sixty-five infants returned for follow-up (41 males and 24 females); mean age 9 months (22 days to 17 months). Most (58 of 65; 89.2%) had abnormal neurological findings and 15 (25.9%) had probable kernicterus.

CONCLUSION

There is a critical need for a National Kernicterus Registry to document all cases of kernicterus and formulate an effective treatment and prevention policy.

Identification of neonatal haemolysis: an approach to predischarge management of neonatal hyperbilirubinemia

AIM

Relative contributions of increased production [by end-tidal carbon monoxide concentrations (ETCOc)] and decreased elimination of bilirubin to predischarge hour-specific total bilirubin (TB) levels were assessed in healthy late-preterm and term newborns. Secondly, we report predischarge ETCOc ranges to guide clinical management of hyperbilirubinemia.

METHODS

TB and ETCOc (≤3 timepoints) determinations of newborns aged between six hours and <6 days (n = 79) were stratified by postnatal age epochs. Hyperbilirubinemia risk was assessed by plotting TB values as a function of ETCOc.

RESULTS

Stratifications of ETCOc (in ppm, mean, median and interquartile ranges) by postnatal age epochs (0-24, 24-48 and 48-72) were as follows: 2.0, 1.9, 1.8-2.2 (n = 11); 1.6, 1.5, 1.1-2.0 (n = 58); and 2.0, 1.8, 1.6-2.3 (n = 9), respectively. Infants with ETCOc ≥ 2.5 were at high risk, between 1.5 and 2.5 at moderate risk and ≤1.5 were at low risk. Risk due to haemolysis alone was not independent (p < 0.01). For infants with TB >75th percentile (n = 31), 23% had ETCO ≤1.5, and 77% had ETCOc > 1.5 (p < 0.00003).

CONCLUSION

Near-simultaneous ETCOc and TB measurements in infants with TB >75th percentile accurately identify haemolytic hyperbilirubinemia.

Impact of bilirubin-induced neurologic dysfunction on neurodevelopmental outcomes

Bilirubin-induced neurologic dysfunction (BIND) is the constellation of neurologic sequelae following milder degrees of neonatal hyperbilirubinemia than are associated with kernicterus. Clinically, BIND may manifest after the neonatal period as developmental delay, cognitive impairment, disordered executive function, and behavioral and psychiatric disorders. However, there is controversy regarding the relative contribution of neonatal hyperbilirubinemia versus other risk factors to the development of later neurodevelopmental disorders in children with BIND. In this review, we focus on the empiric data from the past 25 years regarding neurodevelopmental outcomes and BIND, including specific effects on developmental delay, cognition, speech and language development, executive function, and the neurobehavioral disorders, such as attention deficit/hyperactivity disorder and autism.

Are the neuromotor disabilities of bilirubin-induced neurologic dysfunction disorders related to the cerebellum and its connections?

Investigators have hypothesized a range of subcortical neuropathology in the genesis of bilirubin-induced neurologic dysfunction (BIND). The current review builds on this speculation with a specific focus on the cerebellum and its connections in the development of the subtle neuromotor disabilities of BIND. The focus on the cerebellum derives from the following observations: (i) the cerebellum is vulnerable to bilirubin-induced injury; perhaps the most vulnerable region within the central nervous system; (ii) infants with cerebellar injury exhibit a neuromotor phenotype similar to BIND; and (iii) the cerebellum has extensive bidirectional circuitry projections to motor and non-motor regions of the brainstem and cerebral cortex that impact a variety of neurobehaviors. Future study using advanced magnetic resonance neuroimaging techniques have the potential to shed new insights into bilirubin's effect on neural network topology via both structural and functional brain connectivity measurements.

Direct antiglobulin titer strength and hyperbilirubinemia

BACKGROUND AND OBJECTIVES

We recently demonstrated that direct antiglobulin titer (DAT) positive, blood group A or B newborns born to group O mothers had a high incidence of hyperbilirubinemia, attributable to increased hemolysis. We reanalyzed our data asking whether increasing DAT strength plays a modulating role in the pathophysiology of the hemolysis and hyperbilirubinemia.

METHODS

Data from previously published DAT-positive, ABO-heterospecific neonates were analyzed for hyperbilirubinemia and hemolysis according to strength of DAT. DAT was measured by using a gel agglutination technique and reported as values ranging from DAT ± to DAT ++++. Hemolysis was evaluated by blood carboxyhemoglobin corrected for inspired, ambient CO (COHbc), and expressed as percent total hemoglobin (tHb). Hyperbilirubinemia was defined as any plasma total bilirubin value >95th percentile on the hour-specific nomogram.

RESULTS

Hyperbilirubinemia was more prevalent in those with DAT ++ readings (16 of 20, 80%) than those both DAT ± (37 of 87 [42.5%], relative risk: 1.88, 95% confidence interval: 1.35-2.61) and DAT + (32 of 56 [57.1%], relative risk: 1.40, 95% confidence interval: 1.02-1.92). COHbc values were higher for those with DAT ++ (1.45 ± 0.49% tHb [mean ± SD]) than those DAT ± (1.20 ± 0.37% tHb, P = .01) or DAT + (1.22 ± 0.37% tHb, P = .02).

CONCLUSIONS

DAT ++ readings were associated with a higher incidence of hyperbilirubinemia and higher COHbc values than DAT ± or DAT + counterparts. Increasing DAT strength may be a modulator of hemolysis and hyperbilirubinemia in ABO-heterospecific neonates. DAT strength, and not merely DAT presence or absence, should be taken into consideration in the management of ABO-heterospecific newborns.

Incidence, etiology, and outcomes of hazardous hyperbilirubinemia in newborns

BACKGROUND AND OBJECTIVES

Total serum bilirubin (TSB) levels ≥ 30 mg/dL are rare but potentially hazardous. A better understanding of their incidence, causes, and outcomes could help inform preventive efforts.

METHODS

We identified infants born ≥ 35 weeks' gestational age from 1995-2011 in Kaiser Permanente Northern California (n = 525409) and examined the medical records of infants with a TSB ≥ 30 mg/dL to determine etiology and the occurrence of acute bilirubin encephalopathy. We reviewed inpatient and outpatient encounters through 2013 for evidence of sensorineural hearing loss (SNHL) or cerebral palsy (CP).

RESULTS

We identified 47 infants with TSB ≥ 30 mg/dL (8.6 per 100000 births). In 44 infants (94%), the hyperbilirubinemia occurred after the initial birth hospitalization. The etiology was not identified in 33 (70%). Glucose-6-phosphate dehydrogenase (G6PD) activity was measured in only 25 (53%) of whom 10 (40%) were deficient. Four children had acute bilirubin encephalopathy of whom 2 developed both CP and SNHL, and 1 developed isolated SNHL. These 3 infants all had G6PD deficiency and TSB >40 mg/dL. One additional 35-week infant with TSB 38.2 mg/dL had SNHL.

CONCLUSIONS

Hazardous (≥ 30 mg/dL) hyperbilirubinemia is a rare event. No etiology could be identified from the clinical record in most cases. G6PD deficiency was the leading cause of hazardous hyperbilirubinemia when an etiology was identified, but many were not tested. Chronic, bilirubin-induced neurotoxicity was uncommon and occurred only in the setting of additional risk factors and TSB values well over (>15 mg/dL) the American Academy of Pediatrics exchange transfusion thresholds.

End-tidal carbon monoxide and hemolysis

Hemolytic disease in newborns can result from a number of conditions, which can place such infants at an increased risk for the development of severe hyperbilirubinemia. Because the catabolism of heme produces equimolar amounts of carbon monoxide (CO) and bilirubin, measurements of end-tidal breath CO (corrected for ambient CO) or ETCOc can serve as an index of hemolysis as well as of bilirubin production from any cause. Elevated levels of ETCOc have been correlated with blood carboxyhemoglobin levels and thus hemolysis. However, the detection of hemolysis can be a clinically challenging problem in newborns. Here, we describe the importance of determining ETCOc levels and their application in identifying infants at risk for developing hyperbilirubinemia associated with hemolysis and other causes of increased bilirubin production.

Adult neurobehavioral outcome of hyperbilirubinemia in full term neonates-a 30 year prospective follow-up study

Background. Neonatal hyperbilirubinemia (HB) may cause severe neurological damage, but serious consequences are effectively controlled by phototherapy and blood exchange transfusion. HB is still a serious health problem in economically compromised parts of the world. The long term outcome has been regarded favorable based on epidemiological data, but has not been confirmed in prospective follow-up studies extending to adulthood.

Methods. We studied the long term consequences of HB in a prospective birth cohort of 128 HB cases and 82 controls. The cases are part of a neonatal at-risk cohort (n = 1196) that has been followed up to 30 years of age. HB cases were newborns ≥ 2500 g birth weight and ≥ 37 weeks of gestation who had bilirubin concentrations > 340 µmol/l or required blood exchange transfusion. Subjects with HB were divided into subgroups based on the presence (affected HB) or absence (unaffected HB) of diagnosed neurobehavioral disorders in childhood, and compared with healthy controls. Subjects were seen at discharge, 5, 9 and 16 years of life and parent’s and teacher’s assessments were recorded. At 30 years they filled a questionnaire about academic and occupational achievement, life satisfaction, somatic and psychiatric symptoms including a ADHD self-rating score. Cognitive functioning was tested using ITPA, WISC, and reading and writing tests at 9 years of life.

Results. Compared to controls, the odds for a child with HB having neurobehavioral symptoms at 9 years was elevated (OR = 4.68). Forty-five per cent of the HB group were affected by cognitive abnormalities in childhood and continued to experience problems in adulthood. This was apparent in academic achievement (p < 0.0001) and the ability to complete secondary (p < 0.0001) and tertiary (p < 0.004) education. Also, the subgroup of affected HB reported persisting cognitive complaints e.g., problems with reading, writing and mathematics. Childhood symptoms of hyperactivity/impulsivity (p < 0.0001) and inattention (p < 0.02) were more common in HB groups, but in adulthood the symptoms were equal. The affected HB had lower scores in parameters reflecting life satisfaction, less controlled drinking, but not increased substance abuse.

Discussion. Our results indicate that neonatal HB has negative consequences in adult age. A prospectively collected cohort with strict inclusion criteria enables to control most of the bias factors involved with retrospective data. The control and HB groups were remarkably similar at birth in terms of medical data, and the growth environment of the children, as well as the parents’ social groups, education, size of family, type of housing at birth and at 9 years of age. Our findings bear resemblance to disorders of the fronto-striatal network, and also symptoms of the ADHD spectrum were frequent in the HB group suggesting a link of HB to other neurodevelopmental disorders.

Neonatal hyperbilirubinemia and Rhesus disease of the newborn: incidence and impairment estimates for 2010 at regional and global levels

BACKGROUND

Rhesus (Rh) disease and extreme hyperbilirubinemia (EHB) result in neonatal mortality and long-term neurodevelopmental impairment, yet there are no estimates of their burden.

METHODS

Systematic reviews and meta-analyses were undertaken of national prevalence, mortality, and kernicterus due to Rh disease and EHB. We applied a compartmental model to estimate neonatal survivors and impairment cases for 2010.

RESULTS

Twenty-four million (18% of 134 million live births ≥ 32 wk gestational age from 184 countries; uncertainty range: 23-26 million) were at risk for neonatal hyperbilirubinemia-related adverse outcomes. Of these, 480,700 (0.36%) had either Rh disease (373,300; uncertainty range: 271,800-477,500) or developed EHB from other causes (107,400; uncertainty range: 57,000-131,000), with a 24% risk for death (114,100; uncertainty range: 59,700-172,000), 13% for kernicterus (75,400), and 11% for stillbirths. Three-quarters of mortality occurred in sub-Saharan Africa and South Asia. Kernicterus with Rh disease ranged from 38, 28, 28, and 25/100,000 live births for Eastern Europe/Central Asian, sub-Saharan African, South Asian, and Latin American regions, respectively. More than 83% of survivors with kernicterus had one or more impairments.

CONCLUSION

Failure to prevent Rh sensitization and manage neonatal hyperbilirubinemia results in 114,100 avoidable neonatal deaths and many children grow up with disabilities. Proven solutions remain underused, especially in low-income countries.

Risk factors for neurotoxicity in newborns with severe neonatal hyperbilirubinemia

OBJECTIVE

To evaluate the importance of total serum bilirubin (TSB) and neurotoxicity risk factors in predicting acute bilirubin encephalopathy (ABE) at admission or posttreatment bilirubin encephalopathy (BE) in infants with severe hyperbilirubinemia.

METHODS

We analyzed the interaction of TSB and risk factors as determinants of ABE and BE in 249 newborns admitted with a TSB level of ≥ 25 mg/dL (427 μmol/L) to Cairo University Children's Hospital during a 12-month period.

RESULTS

Admission TSB values ranged from 25 to 76.4 mg/dL. Forty-four newborns had moderate or severe ABE at admission; 35 of 249 infants (14%) had evidence of BE at the time of discharge or death. Rh incompatibility (odds ratio [OR]: 48.6) and sepsis (OR: 20.6) greatly increased the risk for ABE/BE, but TSB levels correlated poorly with the presence or absence of ABE or BE in these patients. The OR for ABO incompatibility with anemia (1.8) was not statistically significant. Low admission weight (OR: 0.83 per 100 g) increased the risk for BE, especially when other risk factors were present. The threshold TSB level that identified 90% of infants with ABE/BE was 25.4 mg/dL when neurotoxicity risk factors were present. In contrast, neurotoxicity was first observed at a TSB level of >31.5 mg/dL in 111 infants without risk factors.

CONCLUSIONS

Newborns without risk factors for neurotoxicity have a higher tolerance for hyperbilirubinemia than recognized in management guidelines. The risk for BE in hemolytic disease varies with etiology. The great variation in response to TSB indicates that biological factors other than TSB values are important in the pathogenesis of BE.

The need for technologies to prevent bilirubin-induced neurologic dysfunction syndrome

Dramatic improvements in the overall socioeconomic conditions have yet to impact the unacceptably high maternal (approximately 1500 maternal deaths daily, worldwide) and neonatal morbidity and mortality (more than 10,000 deaths per daily 200,000 live-births, worldwide) in the developing nations. Thus, nations with emerging markets have unique health-societal needs. All infants require a safer transition from a birthing facility to home during the first week after birth and providing for a nurturing environment to prevent neonatal illnesses is integral to "good clinical practice." The unmonitored occurrence of severe hyperbilirubinemia and kernicterus are emblematic of a fractured maternal child healthcare system. The "know-do" gaps that span private versus public health care systems in the emerging markets have led us to conclude that building an interdisciplinary leadership approach to provide innovative strategies and affordable technologies will help bridge and access existing social barriers in the micro- and macro-health environments. Thus, unfettered access, global benchmarks, and culturally relevant strategies are dependent on evidence-based affordable technologies to successfully transform societal health care practices. Implementation of jaundice-related technologies should serve as a template for other affordable newborn health products.

Severe neonatal hyperbilirubinemia and kernicterus: are these still problems in the third millennium?

Despite efforts to eliminate permanent and irreversible brain damage due to bilirubin encephalopathy and kernicterus, these conditions continue to accompany us into the third millennium. This phenomenon occurs not only in developing countries with emerging medical systems, but in Westernized countries as well. Comprehensive guidelines to detect newborns with jaundice and treat those in whom hyperbilirubinemia has already developed have been formulated in several countries, but have not been successful in completely eliminating the problem. In this appraisal of the situation we review selected aspects of bilirubin encephalopathy and/or kernicterus. We highlight recent reports of severe hyperbilirubinemia and kernicterus, discuss some of the factors responsible for the continuing appearance of these conditions, and briefly review what can be done to decrease bilirubin-related morbidity and mortality to the minimum.

Hemolysis and hyperbilirubinemia in antiglobulin positive, direct ABO blood group heterospecific neonates

OBJECTIVE

We quantified hemolysis and determined the incidence of hyperbilirubinemia in neonates who were direct antiglobulin titer (DAT)-positive, ABO heterospecific, and compared variables among O-A and O-B subgroups.

STUDY DESIGN

Plasma total bilirubin (PTB) was determined before the neonates were discharged from the hospital and more frequently when clinically warranted, in neonates who were DAT positive with blood group A or B and with mothers who had blood group O. Heme catabolism (and therefore bilirubin production) was indexed by blood carboxyhemoglobin corrected for inspired carbon monoxide (COHbc). Hyperbilirubinemia was defined as any PTB concentration >95th percentile on the hour-of-life-specific bilirubin nomogram.

RESULTS

Of 164 neonates, 111 were O-A and 53 O-B. Overall, hyperbilirubinemia developed 85 neonates (51.8%), and it tended to be more prevalent in the O-B neonates than O-A neonates (62.3% versus 46.8%; P = .053). Hyperbilirubinemia developed in more O-B newborns than O-A newborns at <24 hours (93.9% versus 48.1%; P< .0001). COHbc values were globally higher than our previously published newborn values. Babies in whom hyperbilirubinemia developed had higher COHbc values than the already high values of babies who were non-hyperbilirubinemic, and O-B newborns tended to have higher values than their O-A counterparts.

CONCLUSIONS

DAT-positive, ABO heterospecificity is associated with increased hemolysis and a high incidence of neonatal hyperbilirubinemia. O-B heterospecificity tends to confer even higher risk than O-A counterparts.