Doppler assessment of the maternal interlobar renal and uterine arteries in mid-pregnancy in women at low and high risk for pregnancy-induced hypertension.

Abstract

The purpose of this study was to examine the relationship between vascular resistance of the maternal intrarenal arteries and the main uterine arteries in pregnant women at low and high risk for pregnancy-induced hypertension. The resistance indices (RIs) in the main uterine arteries and the interlobar branches of the right renal artery were measured by duplex Doppler sonography in 338 pregnant women at 21-24 weeks of gestation, including 175 women at high risk for pregnancy-induced hypertension. Of those, 54 patients had repeat Doppler measurements during pregnancy. Cross-sectional data showed no correlation between the RIs in the right interlobar renal arteries and either uterine artery. Furthermore, no relationship existed between persistent diastolic notching in the uterine arteries and the RI in the renal circulation. The mean renal artery RI was 0.62. Compared to that in patients with a normal outcome, the renal artery RI was not significantly different in patients who developed proteinuric pregnancy-induced hypertension (PPIH) or severe pregnancy-induced hypertension (PIH) later during pregnancy. Multiple analysis of variance for longitudinal data showed no correlation between the RI in the maternal renal arteries and gestational age, severe PIH, or PPIH. The RIs in the maternal intrarenal arteries and the main uterine arteries are not related to each other in pregnant women, even in patients with abnormal uterine artery Doppler findings, severe PIH, or PPIH.