S100B protein is a biomarker that increases following central nervous system (CNS) damage. Measuring this protein's levels may allow for the early identification of infants at high risk for developmental abnormalities, such as fetal growth restriction (FGR), even on the first day of life, in a non-invasive manner. Early detection could enable timely interventions and rehabilitation, potentially improving the child's prognosis and long-term outcomes. This study investigates two groups of full-term pregnancies: a study group with prenatally diagnosed late FGR, and a control group with normal fetal growth. Following delivery, cord blood samples from both groups will be analyzed for S100B protein concentrations, pH, base excess (BE), and lactate levels. Additionally, fetal blood flow parameters in the umbilical artery (UA), uterine arteries (UtA), ductus venosus (DV), and middle cerebral artery (MCA) will be monitored via ultrasound within 48 hours before delivery. This study aims to compare S100B protein concentrations in umbilical cord blood between the two groups and to assess correlations with fetal Doppler parameters, pH, BE, and lactate levels in cord blood gas analysis. Ultimately, we seek to determine the effectiveness of S100B protein concentration as a biomarker for diagnosing fetal CNS hypoxia- ischemia in FGR-affected children, compared to those with normal growth.