Fetal renal artery Doppler as a predictor of impaired perfusion in preeclampsia

BACKGROUND: Preeclampsia is a common hypertensive disorder of pregnancy, which is associated with reduced placental perfusion and adverse fetal outcomes. Despite its clinical importance, fetal renal hemodynamics in pregnancies with preeclampsia has received little attention. Doppler ultrasound is a noninvasive method for assessing vascular resistance and perfusion in the fetal circulation, including the renal arteries. METHODS: In this cross-sectional case-control study, 160 pregnant women between 25 and 40 weeks of gestation were included in the study. Participants were divided into two groups: preeclampsia (n = 73) and control (n = 87), each containing 30 fetuses diagnosed with IUGR (Total 60 fetuses). Fetal biometry and Doppler indices including pulsatility index, resistance index, systolic-diastolic ratio, end-diastolic flow, and peak systolic velocity were measured in the umbilical and renal arteries. RESULTS: The preeclamptic group showed higher values ​​of umbilical artery PI and RI and lower values ​​of umbilical artery EDV and PSV. Also, the renal artery S/D ratio was higher in this group. In mothers with preeclampsia, IUGR fetuses had higher values ​​of umbilical artery PI and RI and lower values ​​of umbilical artery EDV compared to normally growing fetuses. Renal artery PSV was lower in IUGR fetuses than in non-IUGR fetuses. Severe preeclampsia was associated with higher umbilical artery EDV values, indicating reduced vascular resistance in the fetal umbilical arteries. CONCLUSION: This study shows that abnormal fetal renal artery Doppler indices are more common in pregnancies with preeclampsia and IUGR, indicating increased vascular resistance and reduced renal perfusion. The use of renal artery Doppler can improve prenatal monitoring and risk stratification in high-risk pregnancies.