1.The main causes of dystocia of vertex presentation were occiput malpresentation, macrosomic infant, uterine atony, abnormal pelvic and genital tract.

1.导致难产的主要因素依次为置、巨大儿、宫缩力、软产道及骨产道。

2.Objective:To survey the normal values of pelvic inclination of external pelvimetry and to provide evidence so as to estimate dystocia risk index for antenatal care.

2.量骨盆倾斜度外量正值,为产前检查估计难产风险指数提供依据。