骨盆倾斜度过大的难产机制和纠正机制

Mechanism of Dystocia Due to Excessive Pelvic Inclination and Its Correction

目的 :探讨骨盆倾斜度过大产妇产时的临床表现和纠正机制。方法 :①用骨盆倾斜度测量器测量骨盆倾斜度 ,选择骨盆、脊柱无畸形 ,头盆评分 8分 ,枕前位、单胎 10 0 0例 ,以正常产程图为观察标准 ,观察分娩全过程。②观察10 0例早孕至产前、产前至产后各期孕妇骨盆倾斜度变化。结果 :当测量仪测量骨盆倾斜度≥ 5 3°为倾斜度过大 ,发生率为 7 8%。主要临床表现有 :悬垂腹 ,跨耻征假阳性 ,胎头衔接困难或停滞 ,会阴重度裂伤。结论 :骨盆倾斜度过大是由于腰骶角增大所致。分娩时胎轴压力线指向耻骨联合与骨盆轴不在一条直线上造成胎头衔接困难或停滞。取膀胱截石位使腰骶角变小骨盆倾斜过大得到纠正 。

Objective:To explore the clinical manifestation of excessive pelvic inclination and mechanism of its correction. Methods:①Pelvic inclination angles were measured with an inclinometer in 1000 singleton pregnant women,whose cephalopelvic score 8,occiput-anterior position, and with out malformation of pelvis and spine. The clinical menifestation was inspected throughout delivery. ②Variations of pelvic inclination were also inspected in 100 pregnant women from early pregnancy to antepartum,and to postpartum.Results:Excessive pelvic inclination means >53 degrees in inclinometer,synonymous with >68 degrees in radiographic measurement. Hs prevalence was 7.8%.The main manifestations included:pendulous abdomen,positive span-pubis sign,nonengagement of fetal head, and severe perineum laceration. Conclusions:Excessive pelvic inclination is caused by enlargement of lumber-sacral angle. Head pressure axis directing at pubic is not on the same line with the pelvic axis during delivery,which lead to nonengagement of fetal head. Lumber vertebrae bend will change from ventral to dorsal direction on cyst-lithotomy position,then pelvis move forward and upward with lumber-sacral joint as a pivot. Thus small lumber-sacral angle and excessive pelvic inclination are corrected,and trans-vaginal delivery rate and obstetric quality will also be improved.