Severe neonatal hyperbilirubinaemia in European and Indian subcontinent descendent newborns: a retrospective cohort study.

Neonatal hyperbilirubinaemia is more common in Asian-descendent populations, but differences in disease severity are poorly reported. Our study aimed to compare neonatal hyperbilirubinaemia severity between European and Indian subcontinent descendent newborns. We conducted a single-centre retrospective cohort study including newborns admitted with unconjugated hyperbilirubinaemia (January 2016 to December 2021). Patients were followed during admission, comparing those with European ancestry (control group) and Indian subcontinent ancestry (India, Pakistan, Bangladesh and Nepal) (study group). The primary outcome was severe hyperbilirubinemia (TSB > 25 mg/dL, phototherapy > 6 h or need for exchange transfusion [ET]), and the secondary was TSB levels. Adjusted analysis for potential confounding factors was performed using binary logistic regression models. Of 110 newborns included, 27 (24.5%) had Indian subcontinent ancestry. Occurrence of TSB > 25 mg/dL was significantly higher in the study group (22.2% vs. 4.8%, p = 0.006), while no differences were noted in exposure to phototherapy > 6 h and ET therapy. Logistic regression models for confounding factors adjustment showed Indian subcontinent ancestry as an independent risk factor for TSB > 25 mg/dL (OR 7.49, CI 95% [1.23-45.50]). The study group revealed also higher absolute values of TSB both at admission (22.0 mg/dL vs. 19.6 mg/dL, p = 0.013) and at discharge (13.6 mg/dL vs. 11.4 mg/dL, p = 0.005). Conclusion: Our findings suggest that newborns with Indian subcontinent ancestry might show a higher risk for the development of severe hyperbilirubinemia compared to European ancestry newborns. Implementing earlier treatment thresholds in this subset of patients may help prevent severe hyperbilirubinemia.  What is Known: • Indian subcontinent descendent populations have high incidence of neonatal hyperbilirubinaemia but data regarding its severity are scarce. What is New: • This article shows that, compared to European descendent newborns, Indian subcontinent descendent newborns might be at higher risk for severe hyperbilirubinaemia.