Antioxidant vitamins and hyperbilirubinemia in neonates

OBJECTIVE Low antioxidant system may contribute to the severity of neonatal hyperbilirubinemia. The aim of this research was to explore the relationship between plasma vitamin E and C levels and the severity of hyperbilirubinemia in full-term neonates with normal glucose 6-phosphate dehydrogenase (G6PD) activities. METHODS A total of 130 full-term healthy live birth neonates of healthy mothers with normal G6PD activity were included in this study. In addition to routine blood analysis, plasma total bilirubin, vitamin E and C levels and G6PD activity were measured on the first day of life. None of the neonates was ABO incompatible or anemic. RESULTS Neonates who did not develop hyperbilirubinemia (n=119) had a mean plasma bilirubin level of 65+/-24 micromol/l (median 58.1), while neonates who developed significant hyperbilirubinemia (n=11) had a mean plasma bilirubin level of 238+/-56 micromol/l (median 246.2) on the first day of life. Mean plasma vitamin C levels of neonates who developed hyperbilirubinemia were significantly lower than those who did not develop hyperbilirubinemia (87+/-22 micromol/l (median 89.4) vs. 132+/-36 micromol/l (median 127.7), respectively, P=0.0001). Similar results were observed for plasma vitamin E levels in neonates who did or did not develop hyperbilirubinemia (7.5+/-2 micromol/l (median 6.3) vs. 10.4+/-5 micromol/l (median 9.1), respectively, P=0.001). Hemoglobin and hematocrit were significantly lower in neonates who developed hyperbilirubinemia (P=0.0002 and P=0.0003, respectively), although gestational age and birth weight for the two groups showed no significant difference. CONCLUSION The results of the present work indicate that low level of plasma vitamins C and E are associated with significant hyperbilirubinemia in full-term neonates.