Clinical Application Of Fetal Aortic Isthmus Pulsatility Index In Preeclampsia

Objective:To Analyze the change of the ratio of the middle cerebral artery?MCA?pulsatility index?PI?to the aortic isthmus?AoI?PI in the normal fetuses in the period of 24-38weeks'gestational,and explore the clinical value of MCA-PI/AoI-PI in the fetus of preeclampsia patients.Methods:A total of 173 normal fetuses from 24-38 weeks gestation and 45 pregnancies with preeclampsia that came for prenatal ultrasound examination in our hospital were conducted.The fetal MCA-PI and AoI-PI were measured and the MCA-PI/AoI-PI ratio was calculated.By analyzing the relationship between the MCA-PI/AoI-PI ratio of normal fetus and the gestational week,the changes of MCA-PI,AoI-PI,MCA-PI/AoI-PI ratio with the gestational week were analyzed,and construct the reference range.Select fetuses among the normal fetuses which match the gestational age of fetuses of the pre-eclampsia pregnancies.These two groups were matched 1:1 to analyze the differences of cerebroplacental ratio?CPR??AoI-PI?MCA-PI/AoI-PI between them.The pregnancy outcomes of the case groups were followed up.The relationship between Doppler indicators and adverse pregnancy outcomes was analyzed by Chi-square test and ROC curve.Results:1.MCA-PI first increased and then decreased with gestational week,AoI-PI gradually increased with gestational week,and MCA-PI/AoI-PI gradually decreased with gestational week.Using MCA-PI,AoI-PI,MCA-PI/AoI-PI as the dependent variable X,and the gestational week as the independent variable Y,respectively,a statistical analysis can be performed to obtain the equation:Y_MCA=-0.033+0.145X-0.003X²,r²=0.05,p=0.013;Y_AoI=1.361+0.036X,r²=0.182,p<0.001;Y_{MCA-PI/AoI-PI}=0.262+0.056X-0.001X²,r²=0.152,p<0.001.2.Compared the CPR?AoI-PI?MCA-PI/AoI-PI ratio of normal fetus with,the fetuses of preeclampsia pregnant women,the difference was statistically significant?p<0.05?.3.CPR,AoI-PI,MCA-PI/AoI-PI were all correlated with adverse pregnancy outcomes?p<0.05?.The area under the curve was:MCA-PI/AoI-PI?0.73??CPR?0.68??AoI-PI?0.69?.Conclusion:MCA-PI,AoI-PI,MCA-PI/AoI-PI all change with gestational week.MCA-PI increases first and then decreases with gestational week,AoI-PI gradually increases with gestational week,,and MCA-PI/AoI-PI gradually decreased with gestational week.MCA-PI/AoI-PI of fetuses of preeclampsia pregnant women were significantly lower than normal fetuses.MCA-PI/AoI-PI has predictive value of adverse pregnancy outcomes.