Vetter K, Favre Y, Suter T, Huch R, Huch A
Departement für Frauenheilkunde, Universitätsspital Zürich.
Z Geburtshilfe Perinatol. 1989 Sep-Oct;193(5):215-8.
The observation of characteristic flow changes measured by Doppler ultrasound in the fetal descending aorta a short time before delivery led us to systematically analyse our measurement data. For the retrospective analysis, records with a total of 115 measurements taken in the last four weeks prior to spontaneous onset of labour from 90 women with normal pregnancies were used. For each of the four weekly periods there were between 15 and 50 measurements. Both qualitative and quantitative flow parameters were evaluated. The findings showed: 1. No significant changes in the blood flow characteristics of the uteroplacental and fetoplacental vessels; 2. A clear widening of the diameter of the aorta; 3. A decrease in the mean flow velocity in the descending aorta; 4. A steep decrease in maximum velocity during late systole, sometimes so pronounced that a notch in the flow envelope was observed. The time when the changes occurred was found to be 2 weeks prior to spontaneous onset of labour. These changes in the fetal circulation, which can be called "term effect", occur along with other developments taking place towards the time of birth. They are probably related to the beginning of spontaneous contractions and indicate an adaptation to the changing supply conditions occurring a few days before the onset of labour.
分娩前短时间内通过多普勒超声测量胎儿降主动脉特征性血流变化的观察结果，促使我们对测量数据进行系统分析。在回顾性分析中，我们使用了90名正常妊娠妇女在自然临产开始前最后四周内进行的总共115次测量记录。在四个每周时间段中的每个时间段，测量次数在15至50次之间。对定性和定量血流参数均进行了评估。结果显示：1. 子宫胎盘和胎儿胎盘血管的血流特征无显著变化；2. 主动脉直径明显增宽；3. 降主动脉平均流速降低；4. 收缩期末期最大流速急剧下降，有时非常明显，以至于在血流包络线上观察到一个切迹。发现这些变化发生在自然临产开始前2周。胎儿循环中的这些变化可称为“足月效应”，与临近出生时发生的其他发育过程同时出现。它们可能与自发宫缩的开始有关，并表明对临产前几天发生的供应条件变化的一种适应。
