# Red Cell Distribution Width and RDW-to-Platelet Ratio Patterns Across the Spectrum of Hypoxic–Ischemic Encephalopathy

## TL;DR

The study found that red cell distribution width (RDW) and RDW-to-platelet ratio (RPR) change differently in newborns with varying severities of hypoxic-ischemic encephalopathy.

## Contribution

The paper introduces novel insights into the hematologic patterns of RDW and RPR across different stages of HIE severity.

## Key findings

- RDW showed a blunted postnatal decline in infants with hypoxic-ischemic encephalopathy.
- RPR levels increased with increasing HIE severity, though the increase was not statistically significant.
- RDW remained stable in infants with moderate-to-severe HIE receiving standard care.

## Abstract

What are the main findings?
Across the spectrum of hypoxic–ischemic encephalopathy, RDW demonstrated a blunted postnatal decline, while the RDW-to-platelet ratio (RPR) showed a mild, non-significant increase during the early neonatal period, with higher RPR levels observed in association with increasing HIE severity across Sarnat stages.RDW values decreased significantly in infants with mild HIE, reflecting preserved postnatal hematologic adaptation, whereas RDW remained relatively stable in infants with moderate-to-severe HIE receiving standard care treatment.

Across the spectrum of hypoxic–ischemic encephalopathy, RDW demonstrated a blunted postnatal decline, while the RDW-to-platelet ratio (RPR) showed a mild, non-significant increase during the early neonatal period, with higher RPR levels observed in association with increasing HIE severity across Sarnat stages.

RDW values decreased significantly in infants with mild HIE, reflecting preserved postnatal hematologic adaptation, whereas RDW remained relatively stable in infants with moderate-to-severe HIE receiving standard care treatment.

What is the implications of the main finding?
RDW and RPR, as simple and routinely accessible hematologic indices, may provide complementary information on early inflammatory and hematologic responses in HIE cases. These parameters should be interpreted as descriptive markers of hematologic trajectories rather than as indicators guiding clinical intervention.

RDW and RPR, as simple and routinely accessible hematologic indices, may provide complementary information on early inflammatory and hematologic responses in HIE cases. These parameters should be interpreted as descriptive markers of hematologic trajectories rather than as indicators guiding clinical intervention.

Background: Red cell distribution width (RDW) and the RDW-to-platelet ratio (RPR) have emerged as readily available hematologic markers reflecting systemic inflammation in neonates with hypoxic–ischemic encephalopathy (HIE); however, their early postnatal trajectories across the clinical spectrum of HIE remain insufficiently characterized. Methods: This retrospective cohort study included 229 term or near-term infants diagnosed with HIE. Among them, 166 infants received therapeutic hypothermia, whereas 63 infants who did not undergo cooling served as the reference group. RDW and RPR values were measured at birth and at 72 h of life (after completion of cooling in the hypothermia group). Results: In the reference group, RDW values significantly decreased at 72 h, reflecting normal postnatal hematologic adaptation. In contrast, the hypothermia group demonstrated a blunted decline, with RDW levels remaining relatively stable over the first 72 h, consistent with a blunted early postnatal RDW decline. RPR values showed a mild, non-significant upward trend during the first 72 h of life; however, exploratory analyses suggested an association between higher RPR levels and increasing HIE severity. Conclusions: Across the spectrum of hypoxic–ischemic encephalopathy, RDW demonstrated a blunted postnatal decline, whereas RPR showed a mild, non-significant increase during the early neonatal period. These readily available hematologic markers may provide complementary insights into early systemic inflammatory and hematologic responses in HIE. Prospective multicenter studies are needed to determine their prognostic value and relationship with clinical and neurodevelopmental outcomes.