Causes of severe neonatal hyperbilirubinemia: a multicenter study of three regions in China

Preventive effect of prenatal maternal oral probiotic supplementation on neonatal jaundice (POPS Study): A protocol for the randomised double-blind placebo-controlled clinical trial

INTRODUCTION

Neonatal jaundice is a common and life-threatening health problem in neonates due to overaccumulation of circulating unconjugated bilirubin. Gut flora has a potential influence on bilirubin metabolism. The infant gut microbiome is commonly copied from the maternal gut. During pregnancy, due to changes in dietary habits, hormones and body weight, maternal gut dysbiosis is common, which can be stabilised by probiotics supplementation. However, whether probiotic supplements can reach the baby through the mother and reduce the incidence of neonatal jaundice has not been studied yet. Therefore, we aim to evaluate the effect of prenatal maternal probiotic supplementation on the incidence of neonatal jaundice.

METHODS AND ANALYSIS

This is a randomised double-blind placebo-controlled clinical trial among 94 pregnant women (47 in each group) in a tertiary hospital in Hong Kong. Voluntary eligible participants will be recruited between 28 and 35 weeks of gestation. Computer-generated randomisation and allocation to either the intervention or control group will be carried out. Participants will take either one sachet of Vivomixx (450 billion colony-forming units per sachet) or a placebo per day until 1 week post partum. Neither the study participants nor researchers will know the randomisation and allocation. The intervention will be initiated at 36 weeks of gestation. Neonatal bilirubin level will be measured to determine the primary outcome (hyperbilirubinaemia) while the metagenomic microbiome profile of breast milk and maternal and infant stool samples as well as pregnancy outcomes will be secondary outcomes. Binary logistic and linear regressions will be carried out to assess the association of the microbiome data with different clinical outcomes.

ETHICS AND DISSEMINATION

Ethics approval is obtained from the Joint CUHK-NTEC Clinical Research Ethics Committee, Hong Kong (CREC Ref: 2023.100-T). Findings will be published in peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT06087874.

Clinical and genetic risk factors associated with neonatal severe hyperbilirubinemia: a case-control study based on the China Neonatal Genomes Project

Objective: We aimed to investigate the clinical and genetic risk factors associated with neonatal severe unconjugated hyperbilirubinemia. Methods: This was a retrospective, 1:1 matched, case-control study. We included 614 neonates diagnosed with severe unconjugated hyperbilirubinemia (serum total bilirubin level ≥425 μmol/L or serum total bilirubin concentration that met exchange transfusion criteria) from the China Neonatal Genomes Project in Children's Hospital of Fudan University. Clinical exome sequencing data were analyzed using a data analysis pipeline of Children's Hospital of Fudan University. The factors associated with severe unconjugated hyperbilirubinemia were assessed using univariable and multivariable logistic regression analyses. Interaction analyses were examined between clinical and genetic risk factors. Results: ABO/Rh incompatibility hemolysis (odds ratio [OR] 3.36, 95% confidence interval [CI] 2.32-4.86), extravascular hemorrhage (OR 2.95, 95% CI 2.24-3.89), weight loss (OR 5.46, 95% CI 2.88-10.36), exclusive breastmilk feeding (OR 3.56, 95% CI 2.71-4.68), and the homozygous mutant of UGT1A1 211G>A (OR 2.35, 95% CI 1.54-3.59) were all identified as factors significantly associated with severe unconjugated hyperbilirubinemia. The presence of UGT1A1 211G>A mildly increased the risk of severe unconjugated hyperbilirubinemia caused by ABO/Rh incompatibility hemolysis (OR 3.98, 95% CI 2.19-7.23), although the effect is not statistically significant. Conclusion: ABO/Rh incompatibility hemolysis, extravascular hemorrhage, weight loss, exclusive breastmilk feeding, and the homozygous mutant of UGT1A1 211G>A were found to be risk factors for severe unconjugated hyperbilirubinemia. Clinical factors remain the most crucial and preventable determinants in managing severe unconjugated hyperbilirubinemia, with a minimal genetic contribution. The establishment of preconception care practices and the reinforcement of screening for the aforementioned risk factors are essential steps for preventing severe unconjugated hyperbilirubinemia.

Globus pallidus/putamen T1WI signal intensity ratio in grading and predicting prognosis of neonatal acute bilirubin encephalopathy

Purpose

This study sought to investigate the relationship between the globus pallidus/putamen T1 weighted image (T1WI) signal intensity ratio (G/P ratio) and the acute bilirubin encephalopathy (ABE) in neonates, and to develop a new strategy for the grading and prognosis of ABE based on the G/P ratio.

Methods

A total of 77 full-term neonates with ABE were scored according to bilirubin-induced neurological dysfunction and divided into mild, moderate, and severe groups. Cranial magnetic resonance imaging examinations were performed and the G/P ratio was recorded. The follow-up reexaminations were carried out at 6 months, 1 year, and 2 years after the initial examination. The neonates were then divided into two groups, the good prognosis group and the kernicterus spectrum disorder (KSD) group, according to the evaluation of Gesell Developmental Schedules and Brainstem Audio Electric Potential at 6 months.

Main findings

The differences of G/P ratios were statistically significant, not only among the mild, moderate, and severe ABE groups for the initial examinations but also between the KSD and the good prognosis groups for the follow-up reexaminations. Therefore, the ABE grading model and prognosis predicting model could be established based on the G/P ratio. In the KSD group, the area under the receiver operating characteristic curve of the G/P ratio-based predicting model was 93.5%, the optimal critical point was 1.29, the sensitivity was 88.2%, and the specificity was 93.3%.

Conclusions

The G/P ratio can be used as an indicating parameter for both the clinical grading of neonatal ABE and the assessment of neonatal ABE prognosis. Specifically, the G/P ratio greater than 1.29 indicates a KSD of neonatal ABE.

Severe neonatal hyperbilirubinemia secondary to combined RhC hemolytic disease, congenital hypothyroidism and large adrenal hematoma: a case report

Background

ABO blood group incompatibility, neonatal sepsis, G-6-PD deficiency, thyroid dysfunction, and hereditary spherocytosis are all probable causes of neonatal hyperbilirubinemia. However, the etiology of some hyperbilirubinemia is extremely complicated, which may be caused by multiple factors, resulting in severe jaundice. We report a case of severe jaundice due to three causes, showing the significance for the investigation of the etiology of neonatal hyperbilirubinemia.

Case presentation

At 96 h of life, a full-term and vaginal delivery male infant with yellowish discoloration of body was transferred to our hospital. When he entered neonatal intensive care unit on the fourth day after birth, he developed jaundice and the transcutaneous bilirubin was 28 mg/dl. Total bilirubin was 540.2 μmol/L, while the indirect bilirubin was 516.7 μmol/L. Both parents and the baby’s blood types were O Rh(D +), and direct coomb’s test was negative. But mother’s indirect coomb’s test was positive. Investigating for minor blood group revealed that the father’s blood type of Rh was CCDee, the mather’s was ccDEE, and CcDEe for the baby. After intensive phototherapy and double volume exchange transfusion, the total bilirubin remained at 303 μmol/L. At day 10, the bilirubin level was 303.5 μmol/L, intensive phototherapy was continued, and intravenous immunoglobulin was used again. The test for thyroid hormones at day 10, the TSH was 13.334mIU/L. And the screening for congenital hypothyroidism showed the TSH was 33mIU/L. Because of the palpable abdominal mass, ultrasound and MRI was done, showed a huge mass in the right adrenal gland. Brainstem auditory evoked potential was performed at day 7, which indicated hearing impairment (65db for left ear and 70db for the right). Euthyrox and intermittent phototherapy were given as following treatment. The jaundice did not subside until the 12th day.

Conclusion

Even if their parents' ABO blood group and Rh (d) are consistent, a Coomb test is required for newborns with hyperbilirubinemia since they may have minor blood group incompatibilities. When bilirubin rises rapidly or the clinical treatment effect is inadequate, additional causes should be aggressively screened. Adrenal ultrasound should be performed on newborns with palpable abdominal mass, anemia and jaundice to determine whether there is adrenal hemorrhage.

Bilirubin Encephalopathy

PURPOSE OF REVIEW

Hyperbilirubinemia is commonly seen in neonates. Though hyperbilirubinemia is typically asymptomatic, severe elevation of bilirubin levels can lead to acute bilirubin encephalopathy and progress to kernicterus spectrum disorder, a chronic condition characterized by hearing loss, extrapyramidal dysfunction, ophthalmoplegia, and enamel hypoplasia. Epidemiological data show that the implementation of universal pre-discharge bilirubin screening programs has reduced the rates of hyperbilirubinemia-associated complications. However, acute bilirubin encephalopathy and kernicterus spectrum disorder are still particularly common in low- and middle-income countries.

RECENT FINDINGS

The understanding of the genetic and biochemical processes that increase the susceptibility of defined anatomical areas of the central nervous system to the deleterious effects of bilirubin may facilitate the development of effective treatments for acute bilirubin encephalopathy and kernicterus spectrum disorder. Scoring systems are available for the diagnosis and severity grading of these conditions. The treatment of hyperbilirubinemia in newborns relies on the use of phototherapy and exchange transfusion. However, novel therapeutic options including deep brain stimulation, brain-computer interface, and stem cell transplantation may alleviate the heavy disease burden associated with kernicterus spectrum disorder. Despite improved screening and treatment options, the prevalence of acute bilirubin encephalopathy and kernicterus spectrum disorder remains elevated in low- and middle-income countries. The continued presence and associated long-term disability of these conditions warrant further research to improve their prevention and management.