Objective: To assess the difference between pulsed-wave Doppler (PD) and computerized continuous-wave Doppler (CW) readings of the umbilical artery of 20 parturients in their third trimester of uncomplicated pregnancy. Methods: In a prospective double-blind study, the systolic/diastolic ratio in the umbilical artery was measured 20 min apart by two different physicians with two different instruments (PD and CW). The resistance index (RI), as well as the intra- and interobserver variation were calculated. Results: Interobserver variation was not significant for both techniques (P > 0.05). The mean S/D ratio measured by PD (2.92 ± 0.52) was significantly higher than that measured by CW. The mean RI in the PD readings was also significantly higher than that measured by CW (0.64 ± 0.07 vs 0.61 ± 0.06). The intraobserver variation was much smaller for CW readings of the S/D ratio than for the PD readings. Conclusions: The more accurate computerized readings of the CW appear to be the reason for the difference in measurements.
|Number of pages||3|
|Journal||Journal of Maternal-Fetal Investigation|
|State||Published - 1994|
- Computerized continuous-wave Doppler
- Pulsed-wave Doppler
- Third trimester
- Umbilical artery