Gestational Age–Dependent Association of HALP Score and Systemic Inflammatory Indices with Retinopathy of Prematurity

Background To evaluate the temporal profile and clinical relevance of the hemoglobin–albumin–lymphocyte–platelet (HALP) score and complete blood count–derived inflammatory indices for retinopathy of prematurity (ROP) across gestational age strata. Methods 139 preterm infants born at ≤ 32 weeks were stratified into ≤ 30 and 30–32 weeks. Early (postnatal days 2–4) and month-1 complete blood count parameters were analyzed. Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, systemic immune-inflammation index, systemic inflammation response index, aggregate index of systemic inflammation, and HALP score were calculated at both time points. Comparisons were performed according to ROP status and gestational age strata, and discriminative performance was evaluated using receiver operating characteristic analysis. Results ROP developed in 30 infants (21.6%), including 9 requiring treatment. The ≤ 30-week group had higher ROP incidence and severity. Early indices were not associated with ROP. At month 1, infants ≤ 30 weeks with ROP showed lower albumin and higher composite inflammatory indices (AUC 0.73–0.82), whereas associations were weaker in the 30–32-week group. HALP and platelet-to-lymphocyte ratio demonstrated limited discrimination. Conclusions Month-1 systemic inflammatory activation is associated with ROP predominantly in infants ≤ 30 weeks, indicating a gestational age–dependent inflammatory contribution and potential value for risk stratification.