应用超声心动图探讨妊娠中晚期下腔静脉压迫综合征的临床特征。

选取2016年1月至2018年11月在北京百子湾和美妇儿医院做产检的孕妇42例，依据妊娠中晚期是否有明确下腔静脉压迫症状，将孕妇分为无症状的孕组1（22例）和有症状的孕组2（20例），并纳入年龄相匹配的未妊娠健康女性14名作为对照组。采用超声心动图测量左心室舒张末期径（LVEDD）和收缩末期径（LVESD）、左心室射血分数（LVEF）、右心室基底内径、肺动脉瓣血流速度。分别在平卧位、侧卧位和直立位等不同体位下测量下腔静脉血流峰值速度，计算不同体位峰值速度比值。对以上3组间数据进行单因素方差分析，有统计学意义的采用相应组间两两比较的Bonferroni检验。采用受试者操作特征（ROC）曲线分析下腔静脉血流速度及不同体位下下腔静脉血流速度比值预测下腔静脉受压迫的价值。

与对照组相比，孕妇组左侧卧位和平卧位时下腔静脉血流速度明显增快，差异有统计学意义（F=16.921、21.845，P均<0.05），且有症状孕组2血流速度增快更明显。直立位时下腔静脉血流速度在3组间比较，差异具有统计学意义（P<0.05）。ROC曲线分析下腔静脉血流速度增快超过157.5 cm/s，敏感度69%，特异度23%。卧位与立位下腔静脉血流速度比值大于1.96时，诊断下腔静脉压迫征的敏感度、特异度分别为61%和83%。

中晚期妊娠超声心动图检测下腔静脉血流速度，以及卧位与立位下腔静脉血流速度比值诊断孕中晚期下腔静脉压迫征有重要价值。

To investigate the characteristics of inferior vena cava compression syndrome in the second and third trimesters of pregnancy by echocardiography.

A total of 42 subjects at Beijing Baiziwan Hemei Women's and Children's Hospital from January 2016 to November 2018 [20 with symptoms of inferior vena cava compression (IVCC), 22 without IVCC symptoms] were recruited according to whether there were definite symptoms of IVCC in the second and third trimesters of pregnancy, and 14 age-matched subjects who did not have pregnancy were recruited as controls. The following parameters were recorded: left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), right ventricular basal dimension (RVBD), and pulmonary blood flow velocity. The peak flow velocity of the inferior vena cava was measured in the supine position, lateral position, and upright position, and the ratio of peak velocities in different positions was calculated. One-way analysis of variance (ANOVA) and Student's t-test with post hoc Bonferroni correction were used to compare continuous variables among the three groups and between two groups, respectively. The receiver operator characteristic (ROC) curve was used to analyze the ratio of inferior vena cava blood flow velocity and inferior vena cava blood flow velocity under different positions to predict the compression of inferior vena cava.

Compared with normal controls, the blood flow velocity of the inferior vena cava was significantly increased in the supine position and left lateral position in the pregnant group, and further increased in the symptomatic pregnant women group, and there was a significant difference in blood flow velocity of the inferior vena cava in the upright position among the three groups (P<0.05). In ROC curve analysis, inferior vena cava blood flow velocity>157.5 cm/s showed a 69% sensitivity and 23% specificity in predicting inferior vena cava compression. Additionally, the ratio of the velocity of the inferior vena cava in the supine position to that in the upright position>1.96 showed a 61% sensitivity and 83% specificity in predicting inferior vena cava compression.

Monitoring the flow velocity of the inferior vena cava and the ratio of the velocity of the inferior vena cava in the supine position to that in the upright position is of great clinical significance in predicting inferior vena cava compression in the second and third trimesters of pregnancy.