Association of red blood cell distribution width-coefficient of variation with cranial ultrasound abnormalities in neonatal hyperbilirubinemia: a retrospective cross-sectional study.

Background: Neonatal hyperbilirubinemia frequently leads to severe neurological damage. Although cranial ultrasound (CUS) is crucial for assessing neonatal brain injury, the association between red blood cell distribution width-coefficient of variation (RDW-CV), a marker of red blood cell size variability, and cranial ultrasound abnormalities (CUAs) remains unclear. Objective: The primary aim of this study was to explore the impact of RDW-CV on CUAs in neonatal hyperbilirubinemia and to elucidate the potential clinical implications of this relationship. Methods: This retrospective cross-sectional study included 503 cases of neonatal hyperbilirubinemia at gestational age ≥35 weeks with available RDW-CV and CUS screening data at Nanjing Lishui People's Hospital. Multivariate logistic regression analysis and smooth curve fitting were used to estimate the association between RDW-CV and the risk of CUAs in neonatal hyperbilirubinemia. Results: This study found that the overall prevalence of CUAs in ultrasound images was 26.0%. Multivariate logistic regression analysis adjusted for risk factors revealed that a one-percent increase in RDW-CV increased the risk of CUAs by 23.0%. After conducting a sensitivity analysis of the three RDW-CV quantiles, the findings remained robust and consistent. Conclusions: The study concluded that a higher RDW-CV was associated with a proportional increase in the risk of CUAs. These results demonstrate the importance of RDW-CV in neonatal hyperbilirubinemia. Clinicians should consider this association when managing patients with high RDW-CV.