Ultrasound Detection Of Vascular Endothelial Function For Early Prediction Of Hypertensive Disorders Of Pregnancy

Objective: To explore whether ultrasound examination of vascular endothelial function(referred to herein as flow-mediated dilation function in this thesis)can be an effective and rapid and noninvasive examination method for early prediction of hypertensive disorders of pregnancy,so as to provide reference indexes for early clinical prevention and intervention of potential patients in obstetrics.Methods: FMD parameters of the right brachial artery have been detected by ultrasound in 427 pregnant women between 16 and 20 weeks of gestation and 50non-pregnant women at normal reproductive age.Specific indicators contain resting state and after reactive hyperemia: internal diameter,velocity-time integral and blood flow volume(D1,D2,VTI1,VTI2,Q1,Q2).To calculate internal diameter change△D,internal diameter change rate △D%,blood flow volume change △Q and flow change volume rate △Q% under the two conditions of the brachial artery.All the pregnant women have been followed up to delivery,FMD data of the above pregnant and normal non-pregnant women are grouped as follows: non-pregnant women in normal childbearing age──the healthy women group,pregnant women without HDP──the non-onset group,and having HDP pregnant women──the case group.According to the statistical analysis: the difference of FMD parameters of brachial artery in each group are analyzed by comparing the healthy women group with the non-onset group,the non-onset group with the case group in order to evaluate the effect of brachial artery FMD parameters on the prediction of hypertensive disorders of pregnancy during 16-20 weeks’ pregnancy.Results: The comparison of FMD parameters of the right brachial artery of pregnant women from 16 weeks to 20 weeks between the non-onset group and the case group shows that the FMD blood flow parameters have statistical significance: Q1(P=0.025),Q2(P=0.033),△Q(P=0.002),△Q%(P <0.001).The FMD inner diameter correlation parameter indexes and age have not statistical significance: D1(P=0.227),D2(P=0.075),△D(P=0.291),△D%(P=0.572),and age(P=0.068).Compared with FMD parameters of brachial artery in healthy women group and non-onset group,the three parameters with statistically significant differences between the two groups are:△ D(P=0.011),△ D%(P<0.001)and Q1(P=0.043).There is no significant difference in other FMD parameters and age between the two groups,namely D1(P=0.361),D2(P=0.927),Q2(P=0.238),△Q(P=0.345),△Q%(P=0.432),and age(P=0.404).ROC is used to analyze brachial artery FMD parameters Q1,Q2,△Q,△Q% in the non-onset group and the case group.The results show,Q1: AUC 0.630,95%CI [0.582,0.676],P=0.017;Q2: AUC 0.627,95%CI[0.579,0.673],P=0.007;△Q: AUC 0.682,95%CI [0.636,0.726],P<0.001;△Q%: AUC 0.738,95%CI [0.694,0.779],P<0.001.By comparing the predictive power of Q1,Q2,△Q,and △Q%with each other,the parameters with statistically significant differences are obtained,namely,△Q% higher than Q1(P=0.009),△Q% higher than Q2(P=0.049),and △Q higher than Q2(P<0.001).There is no significant difference in other FMD parameters:Q1 and Q2(P=0.952),△Q and △Q%(P=0.248),△Q and Q1(P=0.363).Conclusion: The FMD functional parameters of the right brachial artery of pregnant women from 16 weeks to 20 weeks demonstrates the related parameters of blood flow,△Q,△Q%,Q1 and Q2,have certain value for the early prediction of hypertensive disorders of pregnancy,while the indexes of internal diameter parameters(△D,△D%,D1 and D2)have no obvious predicting value during this period.The predicting sensitivity of HDP is general according to the above FMD blood flow parameters of brachial artery,but with high negative predictive value.Therefore,detection of FMD blood flow parameters during 16-20 weeks of gestation can be used to screen HDP high-risk pregnant women among the ordinary pregnant population in the early second trimester.