Maternal renal artery Doppler velocimetry in normotensive pregnancies and pregnancies complicated by hypertensive disorders.

Hypertensive disorders in pregnancy contribute to substantial maternal and perinatal morbidity and mortality. Clinically, these disorders are characterized by hypertension and proteinuria. However, these signs appear some time after the physiologic derangements have been initiated. The primary objectives of this study were as follows: 1) to establish baseline values for the maternal renal artery systolic-diastolic ratio (S/D) as a function of gestational age in normal pregnancies, and 2) to determine whether renal artery blood flow indices can accurately identify those pregnancies complicated by, or destined to develop, hypertensive disorders. Using a pulsed Doppler scanner, maternal renal artery duplex evaluation was performed in four groups of women: normotensive nonpregnant, normotensive pregnant, chronic hypertensive pregnant, and preeclamptic. In 30 normotensive pregnant women followed longitudinally, no change was noted in the renal artery S/D as gestational age advanced, with mean (+/- SD) values of 2.5 +/- 0.20 and 2.6 +/- 0.21 for the left and right sides, respectively. No clinically meaningful discriminations were detected when the four groups were compared. We conclude that maternal renal artery Doppler waveforms are not significantly altered by either pregnancy or hypertensive complications in pregnancy.