The Study Of Fetal Aortic Isthmus Flow Parameters In Fetal Growth Restriction

Objective: To study the role and significance of aortic isthmus(AOI)aortic isthmus flow index(IFI)in evaluating fetal growth restriction(FGR).The relationship between IFI and pulsatility index(PI)of FGR fetal aortic isthmus and FGR perinatal outcome was further evaluated.Methods: Forty-one patients with FGR were taken as observation group,forty-one normal pregnant women as control group from January 2017 to October 2018.The parameters of the observation group and the control group were measured by color Doppler ultrasound.The measurement parameters were: the pulsatility index(PI)of fetal middle cerebral artery(MCA),umbilical artery(UA),ductus venosus(DV),aortic isthmus(AOI),and isthmic flow index(IFI)of the AOI,and all cases were followed up.The gestational effects of all Doppler indices were eliminated by using the Z score.Scatter plot and Mann-Whitney test were used to analyze the difference of AOI-IFI between observation group and control group.The severity of FGR perinatal infants was evaluated by neonatal critical illness score(NCIS).Furthermore,perinatal infants were stratified into two groups according to the NCIS: adverse perinatal outcome group(severe and extremely severe group)(n=21)and good perinatal outcome group(non-severe group)(n=20).Scatter plot and mann-whitney test were used to evaluate the differences of doppler blood flow indexes.Logistic regression and roc curve analyze the relationship between doppler blood flow parameters and perinatal outcomes in the adverse perinatal outcomes group and the good perinatal outcomes group.The sensitivity and specificity of AOI-IFI in predicting perinatal adverse outcomes in fetuses with intrauterine growth restriction were analyzed by four-grid table analysis.Results: 1.The IFI of FGR fetuses was significantly lower than that of normal fetuses,and the difference was statistically significant(P<0.05).2.A scatter plot of the AOI-IFI with FGR showed that the AOI-IFI of the fetuses with poor perinatal outcomes is clearly distributed under the AOI-IFI of the fetuses with good perinatal outcomes,and the difference of AOI-IFI in fetuses between two groups was significant(P <0.05).Logistic regression analysis showed that the adverse perinatal outcomes of FGR fetuses were significantly correlated with AOI-IFI(95%,0.003-0.608).Chi-square analysis showed that AOI-IFI had a sensitivity of 62% and a specificity of up to 95% to evaluate the perinatal outcomes of FGR fetuses.3.The fitting curve value of fetal AOI-PI in the adverse perinatal outcomes group was significantly higher than that of the fetal AOI-PI value in the perinatal outcomes group,and the difference of AOI-PI between the two groups was statistically significant(P <0.05).Logistic regression analysis revealed that AOI-PI(P =0.031)was an independent predictor of adverse perinatal outcomes.The adverse perinatal outcomes with FGR were significantly correlated with elevated AOI-PI(area under the curve 0.7;95%,0.52-0.86;P <0.05).Conclusion: AOI-IFI is important for assessing FGR and clinical management FGR fetuses.AOI-IFI is an independent predictor of adverse perinatal outcomes in FGR fetuses,and it is highly sensitive and specific to assess its perinatal outcomes.AOI-PI is also an independent predictor of adverse perinatal outcomes in FGR fetuses,revealing the potentially important role of doppler imaging of fetal AOI in the clinical monitoring of FGR fetuses.