The Role of Tibial Artery Doppler in Late-Onset Fetal Growth Restriction

Abstract

ObjectivesTo evaluate the role of tibial artery pulsatility index (TA-PI) and tibial-placental ratio (TPR) in distinguishing fetal growth restriction (FGR) from normal pregnancies and to assess their predictive value for adverse neonatal outcomes.MethodsThis prospective observational cohort study was conducted at a tertiary perinatology clinic between 2024 and 2025. A total of 42 pregnant women at 37 weeks of gestation were enrolled and categorized into two groups: FGR (n = 21) and non-FGR controls (n = 21). Doppler ultrasonography was used to assess middle cerebral artery, umbilical artery, cerebroplacental ratio, and tibial artery parameters. Statistical analyses included t-tests, chi-square tests, and receiver operating characteristic curve analysis to evaluate the diagnostic performance of TA-PI and TPR.ResultsTA-PI was significantly higher in the FGR group, indicating increased peripheral vascular resistance, while peak systolic velocity in the tibial artery was significantly lower, suggesting compromised peripheral circulation. Both cerebroplacental and tibial-placental ratios were elevated in FGR fetuses, indicating circulatory redistribution. Tibial-placental ratio showed strong predictive value for distinguishing FGR from normal pregnancies. Neonates with FGR had significantly lower birth weights and lower APGAR scores at one and five minutes. Although neonatal intensive care unit admissions were more frequent in the FGR group, the difference was not statistically significant.ConclusionsTibial artery Doppler measurements reflect peripheral vasoconstriction and may indicate fetal adaptation to hypoxia in FGR. Tibial-placental ratio demonstrates potential as a non-invasive tool for detecting fetal compromise.Advances in knowledgeThis study introduces tibial artery Doppler parameters as promising indicators of fetal hemodynamic adaptation, offering a novel approach to enhancing non-invasive FGR surveillance.