Repeatability of measurement of uterine artery pulsatility index using transvaginal color Doppler.

OBJECTIVE: To assess the repeatability of measuring the pulsatility index of the uterine arteries using transvaginal color Doppler at 23 weeks of gestation. PATIENTS AND METHODS: The pulsatility index was measured in 100 women with singleton pregnancies attending for routine transvaginal Doppler examination of the uterine arteries at 23 weeks. To assess the repeatability of different components of variability, six measurements of the uterine artery pulsatility index were made on one of the uterine arteries in each patient. RESULTS: Six measurements of the pulsatility index were successfully measured in all 100 patients, resulting in a total of 600 measurements. The repeatability was unrelated to the pulsatility index. On 95% of occasions the intraobserver, interobserver and waveform tracing repeatability was less than 0.24, 0.27 and 0.14, respectively. CONCLUSIONS: Measurement of the pulsatility index using transvaginal color Doppler is highly reproducible when the examination is carried out by well-trained operators.