Z评分评价正常中晚孕期胎儿主动脉和肺动脉内径增长

目的 探讨Z评分对评价正常中晚孕期胎儿主动脉（AO）、肺动脉（PA）内径增长的应用价值。方法 通过前后2次产前超声心动图测量332胎正常胎儿的AO内径及PA内径。以AO内径、PA内径为应变量，胎儿双顶径（BPD）、胎儿股骨长径（FL）、孕周（GA）为自变量，建立回归方程，基于此计算AO、PA的Z评分。比较前后2次超声心动图检查Z评分的差异。结果 首次胎儿超声心动图检查时GA为（25.82±2.27）周（18~35周），第2次检查时GA为（30.61±2.28）周（23~39周）。前后2次胎儿超声心动图检查所测胎儿AO内径、PA内径差异均有统计学意义（P均<0.05）。2次超声心动图检查的AO内径及PA内径均随GA、BPD及FL的增长而增长。同一孕妇胎儿AO及PA的Z评分随GA、BPD及FL的增长而相对稳定。前后2次产前超声心动图检查胎儿AO、PA的Z评分的差异均无统计学意义（P均>0.05）。结论 正常胎儿AO和PA内径的增长与生物学参数的增长呈正相关，但Z-评分在中晚孕期相对保持恒定。

Z-scores in evaluation of aortic and pulmonary diameter growth in normal fetuses of second and late trimesters

Objective To explore the application value of Z-scores in evaluating growth of aorta (AO) and pulmonary artery (PA) diameter. Methods AO and PA diameters in 332 normal fetuses were measured twice using fetal echocardiography. Z-scores of AO and PA were obtained based on a simple linear equation using gestational age (GA), biparietal diameter (BPD) and femur length (FL) as independent variables. The difference of Z-scores calculated by twice examinations was evaluated. Results The gestation ages of the first and the second examinations of fetal echocardiography were (25.82±2.27) weeks (range 18-35 weeks) and (30.61±2.28) weeks (range 23-39 weeks). There were statistical significant differences of AO and PA diameters between the first and the second examinations (both P<0.05). AO and PA diameters increased with the growth of GA in all fetuses obtained using two examinations, whereas there was no obvious change of Z-scores of AO and PA with increasing GA, BPD and FL in individual pregnant woman. No statistical significant difference was found for Z-scores of AO and PA between the first and the second examinations (both P>0.05). Conclusion The growth of AO and PA diameters are positively correlated with the growth of biological parameters in normal fetuses, while Z-scores of AO and PA remain constant in second and late trimesters.