Relation between Fetal Renal Artery Doppler and Cerebroplacental Ratio in Growth-Restricted Fetus

Background: The balance of placental and cerebral blood flow in fetuses is reflected by the cerebroplacental ratio (CPR), a crucial Doppler measure. Its function in forecasting unfavorable perinatal outcomes in fetuses with growth restriction is still vital. The aim of this study was to accurately detect changes in the fetal circulation of intrauterine growth restriction (IUGR) fetuses, with special emphasis on renal circulation and its relationship to the cerebroplacental ratio. Methods: A prospective study was conducted on 24 fetuses diagnosed with IUGR. Maternal and fetal characteristics, fetal biometric measurements, and fetal Doppler indices were recorded. Neonatal outcomes, including APGAR scores, respiratory distress syndrome (RDS), and NICU admission, were assessed. Patients were categorized into low CPR (<1.0) and normal CPR (≥1.0) groups for comparative analysis. Results: Fetuses in the low CPR group exhibited significantly higher renal artery and umbilical artery PI, along with decreased MCA PI (p < 0.01 for all), compared to the normal CPR group. Biometric measurements including AC, HC, BPD, and FL were significantly lower in the low CPR group (p<0.01). Neonates with low CPR had lower mean birth weight (1829gvs. 2217g, p=0.01), lower 1- and 5-minute APGAR scores (p=0.03 and 0.04, respectively), and higher NICU admission rates (62.5% vs, p=0.02). CPR showed strong inverse correlations with renal artery PI (r=–0.624, p=0.001) and umbilical artery PI (r=–0.822, p<0.001), and a positive correlation with MCA PI (r=0.856, p<0.001). Conclusion: Low CPR in IUGR fetuses is strongly associated with altered fetal circulation, impaired growth, and adverse neonatal outcomes.