Doppler velocimetry of maternal renal circulation in pregnancy-induced hypertension.

PURPOSE: The purpose of this study was to evaluate whether the Doppler waveforms of the maternal main renal, segmental, and interlobar arteries are altered in women with pregnancy-induced hypertension (PIH) compared with healthy pregnant women. METHODS: Flow waveforms of the maternal main renal, segmental, and interlobar arteries were obtained from 42 healthy pregnant women between 24 and 41 weeks of gestation and 21 women with PIH between 28 and 40 weeks of gestation using pulsed Doppler sonography. We used spectral analysis to measure the peak systolic and end-diastolic velocities and the acceleration time. The presence or absence of the normal early systolic compliance peak-reflective-wave complex (ESP) was assessed in only the main renal artery. RESULTS: The acceleration times of the segmental and interlobar arteries were significantly prolonged in the PIH group compared with those in the healthy pregnant women. Of the 21 women with PIH, 3 showed loss of the ESP in the renal artery, but these changes were not significant. CONCLUSIONS: Decreased systolic acceleration and the absence of ESP, the hemodynamic indicators for significant proximal stenosis, suggest that severe stenosis or continuous vasospasm in the proximal arteries, such as the main renal or segmental artery, may be implicated in the pathogenesis of PIH.