Uterine Artery Pulsatility Index (PI)
Uterine artery
doppler velocity waveforms in twin pregnancies.
Obstet
Gynecol 1993;82(6):978-983
GA (wks) |
50th PERCENTILE |
5th PERCENTILE |
95th PERCENTILE |
20 |
1.54 |
1.04 |
2.03 |
21 |
1.47 |
0.98 |
1.96 |
22 |
1.41 |
0.92 |
1.9 |
23 |
1.35 |
0.86 |
1.85 |
24 |
1.3 |
0.81 |
1.79 |
25 |
1.25 |
0.76 |
1.74 |
26 |
1.2 |
0.71 |
1.69 |
27 |
1.16 |
0.67 |
1.65 |
28 |
1.12 |
0.63 |
1.61 |
29 |
1.08 |
0.59 |
1.57 |
30 |
1.05 |
0.56 |
1.54 |
31 |
1.02 |
0.53 |
1.51 |
32 |
0.99 |
0.5 |
1.48 |
33 |
0.97 |
0.48 |
1.46 |
34 |
0.95 |
0.46 |
1.44 |
35 |
0.94 |
0.44 |
1.43 |
36 |
0.92 |
0.43 |
1.42 |
37 |
0.92 |
0.42 |
1.41 |
38 |
0.91 |
0.42 |
1.4 |
39 |
0.91 |
0.42 |
1.4 |
40 |
0.91 |
0.42 |
1.4 |
41 |
0.92 |
0.42 |
1.41 |
42 |
0.93 |
0.43 |
1.42 |