The Study On The Applied Value Of Cerebroplacental Ratio In Diagnosis Of Fetal Growth Restriction In Late Pregnancy

Fetal growth restriction(FGR)is the main cause of adverse perinatal fetal outcomes.Accurate prenatal diagnosis of FGR can reduce the mortality and morbidity of perinatal fetuses,optimize fetal outcomes and improve the quality of life of newborns.Ultrasonography,as the main method of prenatal monitoring and fetal management during pregnancy,has been playing an important role in evaluating fetal intrauterine growth and development.In recent years,most people believe that the detection rate of FGR can be improved by Doppler ultrasound in late pregnancy,especially the cerebroplacental ratio(CPR),It is not only of diagnostic value for FGR,but also related to the prediction of fetal adverse outcomes.This paper discusses the significance of CPR in fetal monitoring and management from two parts: the diagnosis of FGR by CPR and the prediction of fetal adverse outcomes by CPR.Objective:The Doppler values of cerebroplacental ratio(CPR),umbilical artery(UA),middle cerebral artery(MCA)and fetal estimated weight,actual birth weight,intrauterine development and short-term adverse outcomes were retrospectively analyzed in the First Affiliated Hospital of Chengdu Medical College during the past two years.The purpose of this study is to systematically analyze the clinical value of CPR in diagnosis of fetal growth restriction(FGR)and prediction of adverse fetal outcomes in late pregnancy.Materials and Methods:A retrospective study was conducted on 882 single pregnant women who had established obstetric cards and delivered in the First Affiliated Hospital of Chengdu Medical College from July 2016 to December 2018.All patients were examined by GE Voluson E8 color Doppler ultrasound diagnostic instrument.The probe frequency ranged from 3 MHz to 5 MHz.Biparietal diameter(BPD),head circumference(HC),abdominal circumference(AC),femoral length(FL),UA and MCA pulsatility index(PI),resistance index(RI),Peak systolic velocity(PSV)and end-diastolic peak(EDV)were observed and recorded by acoustic scanning.The CPR(CPR=MCA-PI/UA-PI)was calculated.Fetal weight was estimated by Hadlock formula and the actual weight of the fetus was recorded after birth.According to the birth weight,the fetus was divided into large for gestational fetuses(LGA),small for gestational fetuses(SGA)and appropriate for gestational fetuses(AGA).Among these 882 fetuses,41 cases were LGA,89 cases were SGA and 752 cases were AGA.The intrauterine fetal development and clinical outcomes in the short term after birth were recorded.According to the practice of our hospital,SGA are suspected FGR,and it was considered that FGR was highly suspicious when adverse outcomes occurred in SGA.On the one hand,by calculating the accuracy,sensitivity and specificity of CPR in SGA with adverse outcomes,the correlation between CPR and FGR diagnosis was analyzed,and further compared CPR with MCA-PI and UA-PI in diagnosis of FGR.On the other hand,we further analyzed and compared the predictive efficacy of CPR,UA-PI and MCA-PI for fetal adverse outcomes to explore whether CPR can be used as an important index for ultrasound diagnosis of FGR in late pregnancy.Results:A total of 887 pregnant women were collected in this study.Five of them were excluded because of fetal malformation and were eventually included in 882 fetuses.The gestational weeks were more than 32 weeks.Among them,41 cases were LGA,89 cases were SGA and 752 cases were AGA.There was no significant difference between the general data of each group(P > 0.05).The CPR of SGA was significantly lower than that of AGA and LGA(P < 0.05),and there was no significant difference in CPR between AGA and LGA(P > 0.05).Among 89 SGA,61 had some adverse outcomes,and their CPR was significantly lower than that of SGA without adverse outcomes(P <0.05).When using the critical value of CPR < 1.10 to dignose SGA with adverse outcome,the sensitivity,specificity and AUC were 86.2%,77.4% and 0.80(95% CI,0.75-0.85),respectively.When the critical value of UA-PI was 1.30,the sensitivity and specificity of UA-PI > 1.30 in the diagnosis of SGA with adverse outcomes were 50.0%,68.6% and 0.68(95% CI,0.62-0.75),respectively.The accuracy of diagnosis was lower than that of CPR.There was no significant correlation between MCA-PI and SGA with adverse outcomes(P > 0.05).Of the 882 fetuses included,69 had adverse outcomes,of which 61 came fromSGA and 8 from AGA.When the critical value of CPR was 1.12,the sensitivity,specificity and AUC for predicting fetal adverse outcomes were 85.3%,75.4% and 0.79(95% CI,0.74-0.84).When the critical value of UA-PI was 1.25,the sensitivity and specificity in predicting fetal adverse outcomes were 76.2%,65.7%,and AUC was 0.71(95% CI,0.64-0.78).There was no significant correlation between MCA-PI and predicting fetal adverse outcomes(P > 0.05).To sum up,on the one hand,the abnormal decrease of CPR in late pregnancy can provide diagnostic basis for ultrasound diagnosis of SGA with adverse outcomes,that is,CPR is related to the diagnosis of highly suspicious FGR,so CPR can be used as an important index for ultrasound diagnosis of FGR.On the other hand,abnormal decrease of CPR and abnormal increase of UA-PI are related to the prediction of fetal adverse outcomes.CPR is superior to UA-PI in both diagnostic and predictive values,while MCA has no obvious application value in this study.Conclusion:The abnormal increase of CPR in late pregnancy can provide a key reference for the diagnosis of FGR,and can accurately predict fetal adverse outcomes,and the value of prediction and diagnosis is superior to UA-PI.Therefore,the application of CPR in late pregnancy is very important for the clinical management of fetuses.