Red cell distribution width as a potential prognostic biomarker in fetal growth restriction

Objective: Red cell distribution width (RDW) is a prognostic marker for adverse outcomes in cardiovascular disease. This association has been attributed to the impaired erythropoiesis and abnormal red blood cell survival originating from chronic hypoxic status or poor nutrition. Considering the pathophysiologic association between fetal growth restriction (FGR) and chronic intrauterine hypoxia, which in turn can result in impaired erythropoiesis, RDW could be a biomarker in FGR. To address this issue, we evaluated the RDW in FGR. Study design: The study population consisted of singleton preterm neonates (24-34 weeks of gestation) and RDW in cord blood was measured at delivery, and was compared between small-for-gestational age (SGA) neonates (birthweight <10 percentile) and non-SGA neonates (birthweight >10 percentile). Among them, RDW was also examined according to the adverse neonatal outcomes. Results: Five hundred eighty-four neonates were included, of these, 117 SGA neonates and 467 non-SGA neonates. RDW in the SGA neonates was significantly higher than that in the non-SGA neonates (18.4 versus 16.4, p < .001). This association between SGA and RDW remained significant after adjustment for gestational age at delivery, histologic chorioamnionitis, and hematologic parameters. Among the SGA neonates, RDW was higher in neonates with adverse neonatal outcomes than those without them. The RDW >90 percentile was an independent parameter for the prediction of neonatal outcomes, even after adjustment. Conclusion: The RDW was higher in the SGA neonates and was associated with adverse outcomes. RDW can be a prognostic marker in predicting outcomes among preterm neonates.