ABSTRACT
Objective To analyze the Doppler indices of uterine artery at 11-16 weeks normal gestation. Methods Two hundred and ninty-seven normal pregnant women were consecutively recruited to take routine ultrasound examination at 11-16 weeks' gestation. According to gestational week, they were divided into 6 groups (11-11+6 weeks, 12-12+6 weeks, 13-13+6 weeks, 14-14+6 weeks, 15-15+6 weeks, 16-16+6 weeks). According to the location of placenta, they were divided into 3 groups (central placenta, right placenta, left placenta). Finally, the pregnant women were divided into 5 groups (RI<0.60 group, 0.60-0.69 group, 0.70-0.79 group, 0.80-0.85 group and ≥ 0.85 group) according to resistance index (RI). Doppler indices of uterine artery were measured in each case. Results (1) The PIm, RIm, S/Dm values (the mean PI, RI, S/D values of bilateral uterine artery) were decreased with the progress of pregnancy, but the difference of the RIm, S/Dm were not significant. Only the decrease of PIm after 15 weeks was significant (P<0.05). The mean PIm of each group was:11 weeks 1.96±0.39, 12 weeks 1.94±0.45, 13 weeks 1.79±0.43, 14 weeks 1.79±0.36, 15 weeks 1.51±0.43, 16 weeks 1.50±0.30. (2) The PI, RI, S/D values of uterine artery with placenta attached were lower than the other side. In the left placenta group, bilateral RI difference was-0.04 (t=-3.095, P=0.005), bilateral PI difference was -0.24 (t=-3.232, P=0.004), bilateral S/D difference was-1.00 (t=-2.965, P=0.007);in the right placenta group, bilateral RI difference was 0.04 (t=6.159, P=0.000), bilateral PI difference was 0.43 (t=6.614, P=0.000), bilateral S/D difference was 2.05 (t=6.378, P=0.000);in the middle placenta group, bilateral RI difference was 0.02 (t=4.150, P=0.000), bilateral PI difference was 0.14 (t=4.475, P=0.000), bilateral S/D differencewas 0.54 (t=4.376, P=0.000). (3) According to the RI, incidence rates ofα-notch detected:in<0.60 group both sides were 0;in 0.60-0.69 group, left uterine artery was 0.08, right uterine artery was 0.08;in 0.70-0.79 group, left uterine artery was 0.34, right uterine artery was 0.31;in 0.80-0.85 group, left uterine artery was 0.65, right uterine artery was 0.72;in≥0.85 group, left uterine artery was 0.81, right uterine artery was 0.87. Conclusion The uterine artery Doppler indices of 11-16 weeks maybe a reliable and non-invasive method for examining uteroplacental perfusion.