Obstet Gynecol 77 ( 1991) 209 Search in Google ScholarĨ. Forouzan I, AW Cohen, P Arger: Measurement of systolic-diastolic ratio in the umbilical artery by continuous-wave and pulsed-wave Doppler ultrasound: comparison at different sites.

New York, John Wiley, 1981 Search in Google Scholarħ. Fleiss J: Statistical methods for rates and proportions (2nd edn). Eur J Obstet Gynecol Reprod Biol 96 ( 2001) 150 Search in Google ScholarĦ. Di Naro E, F Ghezzi, L Raio, M Franchi, V D'Addario: Umbilical cord morphology and pregnancy outcome. Obstet Gynecol 86 ( 1995) 990 Search in Google Scholarĥ. Degani S, RM Lewinsky, H Berger, D Spiegel: Sonographic estimation of umbilical coiling index and correlation with Doppler flow characteristics. Ultrasound Obstet Gynecol 22 ( 2003) 85 Search in Google ScholarĤ. Bland JM, DG Altman: Applying the right statistics: analyses of measurement studies. Ultrasound Obstet Gynecol 26 ( 2005) 162 Search in Google Scholarģ. Acharya G, T Wilsgaard, GK Berntsen, JM Maltau, T Kiserud: Reference ranges for serial measurements of blood velocity and pulsatility index at the intra-abdominal portion, and fetal and placental ends of the umbilical artery. J Ultrasound Med 8 ( 1989) 219 Search in Google ScholarĢ. The importance of choosing the placental end of the cord. Abramowicz JS, SL Warsof, J Arrington, DL Levy: Doppler analysis of the umbilical artery.

Since discordances in PI between both arteries are more pronounced at the perivesical site, it seems mandatory to evaluate both arteries in this segment.ġ.

Whereas about 20% of cases showed a percentage of PI difference between arteries greater than 20% at free-loop and placental end sites, and at the perivesical site this figure was 45%.Ĭonclusions: The perivesical sampling site for UA PI calculation is more reliable than at a free-floating loop, albeit without significance, and is significantly more reliable than at the placental end of the umbilical cord. The Intraclass correlation coefficients at each site were 0.51, 0.59 and 0.67, respectively. Results: The mean percentage of PI difference between arteries was 15.2, 14.5 and 22% at the placental end, free-loop and perivesical site, respectively. Reliability analyses were performed between observers and between arteries at each sampling site. The PI was calculated by two independent operators from both umbilical arteries at the placental end, at a free-floating loop and at the perivesical segment. Methods: One hundred consecutive singleton pregnancies between 24 and 40 weeks were included. Objectives: To analyse the inter-observer and inter-artery reliability of the umbilical artery (UA) pulsatility index (PI) at different sampling sites.

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