Renal arterial blood flow velocity waveforms in pregnant women.

Seventy-two continuous-wave Doppler ultrasonographic examinations were performed on nine nonpregnant and 56 normal pregnant women. The range of gestation was 6 to 40 weeks, and the objective was to record the renal arterial blood flow velocity waveform. Acceleration time and systolic per diastolic ratio of renal arterial blood flow velocity waveforms were assessed. Of 72 examinations, 68 recordings were made of the left renal artery (94.4%) and 28 of the right renal artery (38.9%), respectively. There was no correlation between acceleration time and systolic per diastolic ratio and gestational age, respectively, and no correlation between acceleration time and systolic per diastolic ratio, and caliceal diameter of the renal pelvis, respectively. Acceleration times of the left and right renal arteries were 47 +/- 11 and 40 +/- 8 msec in nonpregnant women and 62 +/- 23 and 62 +/- 23 msec in pregnant women, respectively. The left and right systolic per diastolic ratios were 3.1 +/- 0.7 and 2.9 +/- 0.5 in nonpregnant women and 2.8 +/- 0.6 and 2.6 +/- 0.5 in pregnant women, respectively. Therefore these data provide a foundation for the study of hydronephrosis, which may occur in pregnant women.