New Marker in the Umbilical Cord Blood of Fetuses with Fetal Growth Restriction: Serum Sortilin-1 Level

<b>Objective:</b> To determine the role of sortilin in the pathogenesis of fetal growth restriction (FGR) by examining serum sortilin levels in fetal cord blood. <b>Methods:</b> This prospective case-control study was conducted at Ankara Etlik City Hospital between July 2023 and January 2024. Group 1 included 44 pregnant women with late FGR; Group 2 included 44 healthy pregnant women as controls. <b>Results:</b> Umbilical cord blood sortilin levels were significantly higher in the FGR group [2.96 (2.43-4.01)] compared to the control group [2.12 (1.74-3.18)] (<i>p</i> = 0.001). Sortilin levels negatively correlated with APGAR scores at 1 min (r=-0.281, <i>p</i> = 0.008) and 5 min (r=-0.292, <i>p</i> = 0.006). A sortilin threshold of 2.58 ng/ml predicted composite adverse neonatal outcomes with 66.7% sensitivity, 53.1% specificity, and an AUC of 0.652 (95% CI: 0.529-0.775, <i>p</i> = 0.031). <b>Conclusion:</b> This study showed that sortilin levels, which are indicators of oxidation, were higher in the cord blood of newborns with late FGR.