Jaundice technologies: prediction of hyperbilirubinemia in term and near-term newborns

Incidence, aetiology and short term outcomes of extreme hyperbilirubinaemia, in term infants born in the Western health subdistrict of Cape Town, South Africa between 2019 and 2020

Extreme levels of bilirubin in newborn is a major cause of lifelong neurodevelopmental impairment, which places a financial burden on healthcare resources and caregivers. To determine the incidence, aetiology and short-term outcomes of extreme hyperbilirubinaemia in term infants born in a resource-limited setting. This is a retrospective observational study looking at term neonates with a birth weight ≥2500 g, born in the Western health subdistrict of Cape Town, South Africa, between 1 January 2019 and 31 December 2020, who were exposed to a serum bilirubin level of ≥430 μmol/L in the first week of life and received care in the public health system. Extreme hyperbilirubinaemia occurred in 59 term infants. The incidence was 74 cases per 100 000 (<0.01%) live births equating to 1 case in every 1345 live births. The cause of hyperbilirubinaemia was identified in 51 of the cases (86%), the most common being ABO incompatibility (31/51, 61%), followed by glucose-6-phosphate dehydrogenase deficiency (11/51, 22%). Twelve infants (20 %) underwent an exchange transfusion. Six infants were encephalopathic. Forty-seven infants (80%) were readmitted after initial post-natal discharge, with a mean age of readmission of 113 h old (SD 31 h). The incidence of extreme hyperbilirubinaemia in the Western health subdistrict of Cape Town is higher than in high-income settings. Further work should focus on training of healthcare workers and education of caregivers, for the early detection of significant hyperbilirubinaemia to prevent neurological complications caused by bilirubin toxicity.

Exposure to air pollutants during pregnancy and after birth increases the risk of neonatal hyperbilirubinemia

OBJECTIVES

Exposure to air pollution is associated with increased risks of several adverse conditions in newborns, such as preterm birth. Whether air pollution is associated with neonatal hyperbilirubinemia remains unclear. We aimed to develop and validate an air-quality-based model to better predict neonatal hyperbilirubinemia.

METHODS

A multicenter, population-based cohort of neonates with a gestational age (GA) ≥35 weeks and birth weight ≥2000 g was enrolled in the study. The study was conducted in Shanghai, China, from July 2017 to December 2018. The daily average concentrations of particulate matter (PM) with aerodynamic diameters≤2.5 μm (PM2.5) and ≤10 μm (PM10), sulfur dioxide (SO₂), nitrogen dioxide (NO2) and carbon monoxide (CO) were measured. Neonatal hyperbilirubinemia was diagnosed according to the American Academy of Pediatrics (AAP) guidelines by trained neonatologists. We used logistic least absolute shrinkage and selection operator (LASSO) regression to screen air pollutant indicators related to neonatal hyperbilirubinemia and build an air-quality signature for each patient. An air-quality-based nomogram was then established to predict the risk of neonatal hyperbilirubinemia.

RESULTS

A total of 11196 neonates were evaluated. Prenatal PM10, CO and NO₂ exposure and postpartum SO₂ exposure were significantly associated with neonatal hyperbilirubinemia. The air-quality score was calculated according to the hyperbilirubinemia-related pollutants. The air-quality score of the hyperbilirubinemia group was significantly higher than that of the nonhyperbilirubinemia group (P < .01, odds ratio = 2.97). An air-quality-based logistic regression model was built and showed good discrimination (C-statistic of 0.675 [95% CI (confidence interval), 0.658 to 0.692]) and good calibration. Decision curve analysis showed that the air-quality-based model was better than the traditional clinical model in predicting neonatal hyperbilirubinemia.

CONCLUSIONS

The findings of this study suggest that ambient air pollution exposure is associated with an increased risk of neonatal hyperbilirubinemia. Our results encourage further exploration of this possibility in future studies.

Analysis of Maternal and Neonatal Complications in a Group of Patients with Gestational Diabetes Mellitus

Background and Objectives: Gestational diabetes mellitus (GDM) represents one of the most common complications during pregnancy, being associated with numerous maternal and neonatal complications. The study aimed to analyze maternal and neonatal complications associated with GDM. The risk factors of GDM and of the maternal and neonatal complications were studied in order to prevent their occurrence. Materials and Methods: The study included 97 women in the study, who underwent an oral glucose tolerance test (OGTT) between weeks 24–28 of pregnancy, consequently being divided into two groups: pregnant women with and without GDM. Statistical analysis was performed using the SPSS 26.0 software and MATLAB fitglm, the results being considered statistically significant if p < 0.05. Results: We observed statistically significant differences between the group of women with and without GDM, regarding gestational hypertension (17.6% vs. 0%), preeclampsia (13.72% vs. 0%), and cesarean delivery (96.1% vs. 78,3%). Data on the newborn and neonatal complications: statistically significant differences were recorded between the two groups (GDM vs. no GDM) regarding the average weight at birth (3339.41 ± 658.12 g vs. 3122.83 ± 173.67 g), presence of large for gestational age (21.6% vs. 0%), macrosomia (13.7% vs. 0%), excessive fetal growth (35.3% vs. 0%), respiratory distress (31.4% vs. 0%), hospitalization for at least 24 h in the Neonatal Intensive Care Unit (9.80% vs. 0%), and APGAR score <7 both 1 and 5 min following birth (7.8% vs. 0%). Additionally, the frequency of neonatal hypoglycemia and hyperbilirubinemia was higher among newborns from mothers with GDM. Conclusions: The screening and diagnosis of GDM is vital, and appropriate management is required for the prevention of maternal and neonatal complications associated with GDM. It is also important to know the risk factors for GDM and attempt to prevent their appearance.

High unbound bilirubin for age: a neurotoxin with major effects on the developing brain

Neonatal hyperbilirubinemia is one of the most frequent diagnoses made in neonates. A high level of unconjugated bilirubin that is unbound to albumin is neurotoxic when the level exceeds age-specific thresholds or at lower levels in neonates with neurotoxic risk factors. Lower range of unbound bilirubin results in apoptosis, while moderate-to-high levels result in neuronal necrosis. Basal ganglia and various brain stem nuclei are more susceptible to bilirubin toxicity. Proposed mechanisms of bilirubin-induced neurotoxicity include excessive release of glutamate, mitochondrial energy failure, release of proinflammatory cytokines, and increased intracellular calcium concentration. These mechanisms are similar to the events that occur following hypoxic-ischemic insult in neonates. Severe hyperbilirubinemia in term neonates has been shown to be associated with increased risk for autism spectrum disorders. The neuropathological finding of bilirubin-induced neurotoxicity also includes cerebellar injury with a decreased number of Purkinje cells, and disruption of multisensory feedback loop between cerebellum and cortical neurons which may explain the clinical characteristics of autism spectrum disorders. Severe hyperbilirubinemia occurs more frequently in infants from low- and middle-income countries (LMIC). Simple devices to measure bilirubin, and timely treatment are essential to reduce neurotoxicity, and improve outcomes for thousands of neonates around the world.

Neonatal hyperbilirubinemia and early discharge from the maternity ward

Early discharge from the maternity hospital is almost becoming the rule: it is not clear if this practice actually increases the rate of newborn rehospitalization, but it surely poses some problems for jaundice management, since hyperbilirubinemia is the most frequent reason for hospital readmission. Available guidelines for jaundice management and early discharge are reviewed. Evidence-based update is given about four new points: use of gestational age as predictor jointly with the nomogram evaluation, two-point bilirubin assay, and rate of rise evaluation; choice of the "right" curve and unforeseen jaundice risk factors. In conclusion, available predictive tools allow reliable jaundice prediction and safe early discharge if adequate follow-up is planned according to the prediction. Advice about things to avoid is provided together with a practical flowchart based on guidelines and recent evidence-based data.

Point of care testing: transcutaneous bilirubinometry in neonates

Physicians taking care of infants in the first days of life are often faced with neonatal jaundice, especially in an era where post-partum discharge occurs earlier and assessment of newborn bilirubinemia status is required prior to discharge. The Canadian Pediatric Society and the American Academy of Pediatrics have developed and published guidelines for the diagnosis and management of hyperbilirubinemia in newborns. Point of care testing refers to any test performed outside of laboratory by clinical personnel and close to the site of patient care. Based on a summary of multiple reports during the last twenty years, we realize that devices which provide a non-invasive transcutaneous bilirubin (TcB) measurement have proven to be very useful as screening tools and provide a valid estimate of the total serum bilirubin level (TSB). Published data suggest that these devices provide measurements within 30-50 micromol/L of the TSB levels and can replace laboratory measurement particularly when TSB levels are less than 260 micromol/L. At the present time, in the literature, evidence is insufficient to abandon neonatal serum bilirubin testing and replace it with TcB. Any measurement, TSB or TcB, has potential for error. However, we have evidence that TcB, can help avoiding potential errors associated with even visual assessment of jaundice and may be useful as screening device to detect significant jaundice and decrease a large number of unnecessary skin punctures. The current manuscript is based on a careful comprehensive literature review concerning neonatal hyperbilirubinemia. We consider that this manuscript will help clinicians and laboratory professionals in the management of neonatal jaundice.

Early recognition of neonatal hyperbilirubinemia and its emergent management

Hyperbilirubinemia and kernicterus are re-emerging as prominent clinical concerns and have been hypothesized to be secondary to increased breast-feeding rates, early hospital discharges and overall lack of concern for the potential impact of severe hyperbilirubinemia on healthy term newborns. Although the clinical symptoms can be non-specific and vague, they could be early, insidious and heralding signs of acute bilirubin encephalopathy (ABE) or acute stage kernicterus. Because it is highly prevalent, evaluation of a jaundiced neonate requires detailed questions about specific signs, review of birth and postnatal histories, evaluation of predischarge data, and possibly an emergency clinical evaluation of the neurological status of the infant. Medical urgency to evaluate, investigate and monitor such a newborn ensues from the possibility of rapid progression that might lead to permanent sequelae of bilirubin-induced neurologic dysfunction (BIND). Early recognition of the urgency and rapid transition to treatment seem to be the major barriers leading to delay in therapy. However, because there is a well-established and relatively safe treatment for neonatal jaundice, there should be zero tolerance for kernicterus, and BIND prevention has become a national priority in the USA. This paper reviews the clinical signs and epidemiology of ABE and BIND and presents a system-based strategy for preventing their occurrence, focusing particularly on the transition from recognition of clinical jaundice to actual treatment. A novel emergency-room-based protocol is presented as an example of how to expedite and facilitate rapid progression to treatment.

Diagnosis and management of hyperbilirubinemia in the term neonate: for a safer first week

New data support restructuring the approach toward diagnosis and management of hyperbilirubenia in the term neonate to make it more physician-friendly and gain wider implementation. The authors advocate clear criteria for patient safety, preventive approaches, and timely interventions. Structural changes to facilitate a system-based approach should include predischarge bilirubin management; follow-up bilirubin management; and lactational support and nutritional management. The authors advocate total serum bilirubin screening and a scoring system based on clinical risk factors as predischarge screening strategies; we should screen all babies for hyperbilirubinemia and for targeted follow-up based on an hour-specific total serum bilirubin measured for risk assessment. We should also provide focused universal education emphasizing adequate lactational nutrition, to decrease severe hyperbilirubinemia and thus prevent kernicterus.

New concepts in bilirubin encephalopathy

Revised concepts of bilirubin encephalopathy have been revealed by studies of bilirubin toxicity in cultured CNS cells and in congenitally jaundiced Gunn rats. Bilirubin neurotoxicity is related to the unbound (free) fraction of unconjugated bilirubin (Bf), of which the dominant species at physiological pH is the protonated diacid, which can passively diffuse across cell membranes. As the binding affinity of plasma albumin for bilirubin decreases strikingly as albumin concentration increases, previously reported Bf values were underestimated. Newer diagnostic tests can detect reversible neurotoxicity before permanent damage occurs from precipitation of bilirubin (kernicterus). Early toxicity can occur at Bf only modestly above aqueous saturation and affects astrocytes and neurons, causing mitochondrial damage, resulting in impaired energy metabolism and apoptosis, plus cell-membrane perturbation, which causes enzyme leakage and hampers transport of neurotransmitters. The concentrations of unbound bilirubin in the cerebro-spinal fluid and CNS cells are probably limited mainly by active export of bilirubin back into plasma, mediated by ABC transporters present in the brain capillary endothelium and choroid plexus epithelium. Intracellular bilirubin levels may be diminished also by oxidation, conjugation and binding to cytosolic proteins. These new concepts may explain the varied susceptibility of neonates to develop encephalopathy at any given plasma bilirubin level and the selective distribution of CNS lesions in bilirubin encephalopathy. They also can suggest better strategies for predicting, preventing and treating this syndrome.

Newborn jaundice and kernicterus--health and societal perspectives

Kernicterus, a preventable injury to the brain from severe neonatal jaundice, has re-emerged in the United States as a public and societal health concern. Kernicterus, in its usually recognized form, causes devastating disabilities, including athetoid cerebral palsy and speech and hearing impairment. This condition not only ranks amongst the highest cost per new case (per CDCs Financial Burden of Disability study, 1992), but also results in profound and uncompromising grief for the family and loss to siblings of healthy, talkative playmates. And for the child with kernicterus (usually remarkably intelligent, but trapped in an uncontrollable body), grief and frustration are enormous. In 2001 national healthcare organizations, including Centers for Disease Control (CDC), the Joint Commission for the Accreditation of Healthcare Organizations (JACHO) and the American Academy of Pediatrics (AAP) issued alerts to all accredited hospitals and public health professionals in the United States that all healthy infants are at potential risk of kernicterus if their newborn jaundice is unmonitored and inadequately treated. The re-emergence of kernicterus in the United States is the result of interacting phenomena including (a) Early hospital discharge (before extent of jaundice is known and signs of impending brain damage have appeared); (b) Lack of adequate concern for the risks of severe jaundice in healthy term and near newborns; (c) An increase in breast feeding; (d) Medical care cost constraints; (e) Paucity of educational materials to enable parents to participate in safeguarding their newborns; and (f) Limitations within in healthcare systems to monitor the outpatient progression of jaundice. A multidisciplinary approach that encompasses both healthcare and societal needs should be evaluated at a national level for practical and easy to implement strategies. An approach that is based on principles of evidence-based medicine, patient-safety and family centeredness is presented in this article. These strategies should also be based on public awareness campaign such that the healthcare providers can attempt to achieve a "Zero Tolerance of Kernicterus" and thereby decrease both childhood disabilities and infant mortality within the community.