Method To compared with UA and MCA's Doppler parameter in the 44 cases umbilical cord around neck by caesarean section fetus and 61 cases by parturition fetus, take ri and VP as analysis target.

方法比较44例脐绕颈剖腹产胎儿与61例脐绕颈自然分娩胎儿的脐动脉及大脑中动脉血流多普勒参数，以RI及VP为分析指标。