Mulders L G, Jongsma H W, Wijn P F, Hein P R
Department of Obstetrics and Gynaecology, St. Radboud Hospital, Catholic University of Nijmegen, The Netherlands.
Early Hum Dev. 1988 May;17(1):55-70. doi: 10.1016/s0378-3782(88)80057-4.
Uterine artery blood flow velocity waveforms (FVW) were recorded longitudinally in normal pregnancies (n = 41) at 4-week intervals from a gestational age of 18 weeks onwards. Furthermore, reproducibility of the uterine artery FVWs and the relation with maternal heart rate (MHR) was studied. The uterine artery FVW showed a low resistance flow pattern already from 18 weeks onwards, with high diastolic flow velocity relative to systolic flow velocity. Mean values (+/- S.D.) for the Pulsatility-Index (PI) before and after 32 weeks of normal pregnancy were 0.73 (+/- 0.17) and 0.67 (+/- 0.15) respectively; for the A/B ratio these values were 1.98 (+/- 0.30) and 1.85 (+/- 0.25) respectively. Intra- and interobserver reproducibility could be established for uterine artery FVW analysis. A varying time-period between the FVWs (0-4 min), repositioning of the flow probe and different observers did not cause any systematic effect on the PI, although variation increased in case of a longer time-period between the FVWs. Overall variation of the PI in the reproducibility experiments appeared to be caused more by inter- than intrapatient variance. Inter- and intrapatient variance were in the same range for the results of the longitudinal study. A statistically significant, inverse relationship between uterine artery PI and MHR could be established in a majority of cases. The mean regression coefficient for all patients of the reproducibility study was -0.0061; PI decreases with 0.0061 when maternal heart rate increases 1 beats/min.
从妊娠18周起，每隔4周对41例正常妊娠孕妇进行子宫动脉血流速度波形（FVW）的纵向记录。此外，还研究了子宫动脉FVW的可重复性及其与母体心率（MHR）的关系。从18周起，子宫动脉FVW就呈现出低阻力血流模式，舒张期血流速度相对于收缩期血流速度较高。正常妊娠32周前后搏动指数（PI）的平均值（±标准差）分别为0.73（±0.17）和0.67（±0.15）；A/B比值的这些值分别为1.98（±0.30）和1.85（±0.25）。子宫动脉FVW分析可建立观察者内和观察者间的可重复性。尽管FVW之间的时间间隔较长时变化会增加，但FVW之间不同的时间段（0 - 4分钟）、血流探头的重新定位以及不同的观察者对PI没有产生任何系统性影响。在重复性实验中，PI的总体变化似乎更多是由患者间差异而非患者内差异引起的。纵向研究结果中患者间和患者内差异处于相同范围。在大多数情况下，可以确定子宫动脉PI与MHR之间存在统计学上显著的负相关关系。重复性研究中所有患者的平均回归系数为 -0.0061；母体心率每增加1次/分钟，PI降低0.0061。
