孕中晚期正常胎儿肾动脉体积校正搏动指数的参考值

Volume-corrected renal artery pulsatility index in normal fetuses during the second and third trimester of gestation

目的:测量孕中晚期正常妊娠单胎肾动脉体积矫正搏动指数(vcRAPI),确定正常参考值范围,观察其与孕周的相关性。方法:应用二维超声前瞻性获取2019年1-7月在湘雅二医院行产前检查的22~36孕周正常单胎妊娠胎儿双肾矢状切面和横切面,测量双肾长径、前后径及左右径,使用椭圆体计算公式(长径×左右径×前后径×π/6)估测肾脏体积。应用脉冲多普勒在冠状切面检测肾门处肾动脉搏动指数(RAPI)。RAPI除以估测肾体积得到vcRAPI。建立其正常参考值范围,并绘制其与孕周的关系散点图,拟合多种回归模型,选出最佳拟合曲线并得出相关公式。结果:成功测量540例孕中晚期正常胎儿双肾的vcRAPI,并建立了其正常参考值范围,左、右肾vcRAPI与孕周呈显著负相关(r=-0.780、-0.793,均P<0.001),左肾参数与孕周以S曲线拟合优度最佳,右肾参数以幂函数曲线拟合优度最佳。双肾vcRAPI测值间差异无统计学意义(P>0.05)。结论:孕中晚期妊娠正常胎儿的vcRAPI随孕周增加而降低,提示肾灌注量随孕周增大而增加。双肾vcRAPI并无差异,建立vcRAPI的正常参考值范围可为高危妊娠预测、监测提供参照依据。

Objective To measure the normal single fetal volume-corrected renal artery pulsatility index(vcRAPI)in the middle and late pregnancy,and to determine the normal reference range of vcRAPI and to observe its correlation with gestational age.Methods The sagittal and transverse sections of the kidneys of normal single pregnant fetuses at 22 to 36 gestational weeks in the Second Xiangya Hospital from January to July 2019 were prospectively obtained by two-dimensional ultrasound.Estimated renal volume was calculated as length×transverse×antero-posterior×π/6.Pulse Doppler was used to detect the renal artery pulsatility index(RAPI)at the renal hilum in coronary section.The vcRAPI was obtained by dividing the RAPI by the ipsilateral estimated renal volume.The normal reference range of vcRAPI was established,and the scatter diagram of its relationship with gestational age was drawn.Multiple regression models were fitted to select the best fitting curve and to obtain the relevant formulas.Results A total of 540 normal fetuses were enrolled and the normal reference value range of vcRAPI was established.The vcRAPI of both kidneys was negatively correlated with gestational age(r=-0.793,-0.780;all P<0.001).The left kidney parameters and gestational age were best fitted with S-curve,and the right kidney parameters were best fitted with power curve.There was no difference between the right and left kidney vcRAPI values(P>0.05).Conclusions The vcRAPI of normal fetuses decreases with gestational age,indicating that renal perfusion increases with gestational age.In this study,normal reference range of vcRAPI is established to provide reference basis for prediction and monitoring of complicated pregnancy.