Fetal Renal Artery Doppler Assessment in Early-Onset Fetal Growth Restriction and Its Association With Perinatal Outcomes: A Prospective Cohort Study

Background Fetal growth restriction (FGR) is associated with increased perinatal morbidity and mortality. Chronic fetal hypoxia in FGR leads to redistribution of fetal circulation, prioritizing vital organs such as the brain while reducing perfusion to peripheral organs including the kidneys. Doppler assessment of the fetal renal artery may therefore reflect peripheral vascular resistance and potentially predict adverse perinatal outcomes. Methods Prospective observational cohort study conducted at Dr. Cipto Mangunkusumo National Hospital, Jakarta (October 2025–February 2026). Doppler measurements of fetal renal artery pulsatility index (PI) and resistance index (RI) were obtained. Results A total of 60 participants were included (30 early‑onset FGR and 30 controls). Renal artery RI was significantly higher in early‑onset FGR (p = 0.026). PI did not differ significantly between groups (p = 0.167). No significant association was found between renal Doppler parameters and perinatal outcomes. Conclusion Renal artery RI is increased in early‑onset FGR, suggesting increased peripheral vascular resistance. However, renal Doppler parameters were not significantly associated with perinatal outcomes.