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

Background: Available evidence suggests that our country bear great burden of severe hyperbilirubinemia. However, the causes have not been explored recently in different regions of China to guide necessary clinical and public health interventions.
Methods: This was a prospective, observational study conducted from March 1, 2018, to February 28, 2019. Four hospitals in three regions of China participated in the survey. Data from infants with a gestational age ≥ 35 weeks, birth weight ≥ 2000 g, and total serum bilirubin (TSB) level ≥ 17 mg/dL (342 µmol/L) were prospectively collected.
Results: A total of 783 cases were reported. Causes were identified in 259 cases. The major causes were ABO incompatibility (n = 101), glucose-6-phosphate dehydrogenase deficiency (n = 76), and intracranial hemorrhage (n = 70). All infants with glucose-6-phosphate dehydrogenase deficiency were from the central south region. Those from the central south region had much higher peak total bilirubin levels [mean, 404 μmol/L; standard deviation (SD), 75 μmol/L] than those from the other regions (mean, 373 μmol/L; SD, 35 μmol/L) (P < 0.001).
Conclusions: ABO incompatibility was the leading cause in the east and northwest regions, but cases in the central south region were mainly caused by both ABO incompatibility and glucose-6-phosphate dehydrogenase deficiency, and infants in this region had a much higher peak total bilirubin level. Intracranial hemorrhage may be another common cause. More thorough assessments and rigorous bilirubin follow-up strategies are needed in the central south region.