[Evaluation of hemodynamics of pelvic veins in pregnant women by the ultrasonic pulsed doppler flow velocity analysis].

By means of pulsed Doppler ultrasound, external iliac vein (EIV) velocimetries were carried out on non-pregnant, pregnant and postpartum women. 1. According to the results of a phantom simulation study, the difference between measured values and theoretical values increased when the angle of incidence was over 50 degrees. 2. The coefficient variation of the measured value for ten pregnant women was 4.4 to 9.8%. 3. EIV velocity was 21.4 +/- 7.7cm/sec for non-pregnant women, 20.8 +/- 9.5cm/sec in the 1st trimester, showing no significant difference between the two groups. In the 2nd trimester, it was 8.8 +/- 5.6cm/sec decreasing slightly (p < .001), and 6.1 +/- 3.3cm/sec in the 3rd trimester showing a further decrease (p < 0.01). At 24 hours postpartum, it was 12.7 +/- 4.3cm/sec, an increase over the 3rd trimester (p < 0.001), but it was lower than in non-pregnant women (p < 0.001). At 4 weeks postpartum, it was 19.3 +/- 5.3cm/sec, showing no significant difference from non-pregnant women. The results suggested the following. 1. EIV velocimetry by pulsed Doppler ultrasound is reliable for clinical studies. 2. EIV velocity decreased significantly in the 2nd and 3rd trimesters and recovered to the same level as non-pregnant women by 4 weeks postpartum.