en Clinical Biochemistry Clinical Biochemistry Original Article Original Article <p style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Tahoma;"><span style="line-height:14.0pt">Neonatal indirect hyperbilirubinaemia has been associated with altered redox homeostasis, but the combined pattern of oxidative-stress markers and antioxidant-related vitamins remains uncertain. This study compared these biomarkers between jaundiced and healthy term neonates. This single-centre case&ndash;control study included 60 term neonates aged &le;7 days with indirect hyperbilirubinaemia classified according to the 2022 American Academy of Pediatrics guideline and 60 healthy term controls. Case samples were collected before phototherapy. Serum total bilirubin, reduced glutathione (GSH), and vitamins C, E, and D were measured. Lipid peroxidation was assessed using a spectrophotometric thiobarbituric acid-reactive substances assay and reported as malondialdehyde equivalents. Compared with controls, jaundiced neonates had higher total bilirubin (median 18.60 vs 2.17 mg/dL), TBARS (6.23 vs 4.26 nmol MDA equivalents/mL), and vitamin C (0.94 vs 0.63 mg/dL), and lower GSH (228 vs 370 &micro;mol/L), vitamin E (7.75 vs 10.60 mg/L), and vitamin D (8.66 vs 18.55 ng/mL; 59 cases). All differences remained significant after false-discovery-rate correction and adjustment for head circumference and mode of delivery. No within-group correlation remained significant after correction for multiple testing. Indirect hyperbilirubinaemia was associated with higher TBARS, lower GSH, vitamin E, and vitamin D, and higher vitamin C. These findings indicate an altered redox and vitamin profile but do not establish causality or diagnostic utility. </span></span></span></p> Hyperbilirubinaemia, Neonatal, Oxidative Stress, Malondialdehyde, Glutathione, Vitamin D, Vitamin E, Ascorbic Acid 1335 1344 http://ijmcmed.org/browse.php?a_code=A-10-9171-1&slc_lang=en&sid=1 Enas Jabbar Hasan enasjabbar.edu@uomustansiriyah.edu.iq 100319475328460038269 100319475328460038269 Yes Department of Science, College of Basic Education, University of Al-Mustansiriya, Iraq Abeer J. Hassan 100319475328460038270 100319475328460038270 No Institute of Technical Medical Baghdad, Middle Technical University, Iraq Ammar Adil Jasim 100319475328460038271 100319475328460038271 No Department of Biochemistry, College of Medicine, University of Baghdad,Iraq.