Normally, if the head is at0 Station, the biparietal diameter is at the pelvic inlet and the head is fully engaged. 通常,如果胎头处于零点位置,双顶径与骨盆口契合,那么胎头可以充分进入。
Before the operation, we understand the general form of pelvic by A-P position, the pelvic inlet and exit image. 手术前,以骨盆前后位、出口位、入口位X线片了解骨盆的大体形态。