Hou J R
Zhonghua Fu Chan Ke Za Zhi. 1989 Jan;24(1):15-8, 57-8.
We have studied by means of B type ultrasound, the fetal positions and their progress in 221 cases, among which 117 were serially observed. The results showed a marked increase in the incidence of occipito-posterior position (OP) after onset of labor and marked decrease of occipito-anterior position (OA). The antepartum fetal position was influenced mainly by placental site but during labor also by the type and size of the pelvis. The incidence of OP after onset of labor was 33.03% of which 53.13% could rotate spontaneously to anterior position and be delivered as such but 29.69% remained as persistent occipito-posterior position (POP). We also discussed about the differences in the duration and types of deliveries in OP as determined by different labor processes as well as the relationship between the different labor processes and the three major factors affecting labor, particularly in occiput left posterior and occiput right posterior positions.
我们通过B型超声对221例胎儿的胎位及其进展情况进行了研究，其中117例进行了连续观察。结果显示，临产后枕后位（OP）的发生率显著增加，枕前位（OA）明显减少。产前胎位主要受胎盘位置影响，但分娩时也受骨盆类型和大小影响。临产后枕后位的发生率为33.03%，其中53.13%可自行旋转至前位并以此方式分娩，但29.69%仍为持续性枕后位（POP）。我们还讨论了不同产程所决定的枕后位分娩持续时间和类型的差异，以及不同产程与影响分娩的三大因素之间的关系，特别是枕左后位和枕右后位。
