脐动脉血流S/D值在晚期妊娠中的临床应用

目的：对186名妊娠晚期妇女，通过测定脐动脉血流S／D值来评价胎盘功能。方法：应用彩色多普勒超声诊断仪测定妊娠晚期脐动脉收缩末期峰值（S）与舒张末期峰值（D）的比值。结果：正常晚期妊娠，随着妊娠周数的增加，S／D值逐渐下降，由28孕周时的2．7下降至40周时的2．2，平均每周降低0．056，表明胎儿循环系统逐渐趋向成熟。结论：脐动脉S／D值可以反映胎盘的血流动力学改变，正常晚期妊娠S／D值〈3，如发现S／D值异常，则应及时处理。

The clinical application of umbilical artery flow velocity S/D value on late pregnancy

Objective: To evaluate the functions of placenta by detecting umbilical artery flow velocity S/D value on 186 women of late pregnancy.Methods:Detecting the rate of S/D value by colour Doppler flow image technic.Results: With the increase of weeks of pregnancy,the S/D value of normal late pregnancy will gradually drop-from 2.7 of the 28th week pregnancy to 2.2 of the 40th week pregnancy,dropping by 0.056 on average every week,which indicates the circulatory system of the fetus gradually becomes mature.Conclusion: S/D value can reflect the hemodynamics changes of the placenta.The S/D value in normal late pregnancy is lower than 3.If the S/D value is unnormal,timely treatment should be taken.