Objective: To examine whether the maternal renal interlobar vein impedance index (RIVI) as assessed by first trimester ultrasonography is able to predict the later development of hypertensive disorders of pregnancy. Methods: Venous Doppler parameters of both maternal kidneys were studied in 214 pregnant women at 11 + 0 to 13 + 6 weeks’ gestation. Subjects were classified according to the outcomes related to hypertensive disorders. Detection rates and areas under receiver operating characteristic (ROC) curves were determined for the maternal RIVI impedance as a first trimester predictor for preeclampsia (PE) and gestational hypertension (GH). Results: Among the 214 patients, 22 developed PE (10.3%), 10 developed GH (4.7%), and 182 were unaffected by hypertensive disorders (controls) (85%). In the overall study population, there was no difference in the RIVI between the right (0.44; 0.35–0.50) and left side (0.43; 0.35–0.53), p¼0.86. The average RIVI did not differ among women destined to develop PE (0.46; 0.38–0.57), GH (0.39; 0.33–0.46), or pregnancies uncomplicated by hypertensive disease (0.42; 0.37–0.50), p¼0.16. Area under ROC curve analysis demonstrated that RIVI was not predictive of hypertensive disorders of pregnancy. Conclusion: Maternal RIVI should not be considered a first-trimester marker of hypertensive disorders of pregnancy. [ABSTRACT FROM AUTHOR]