早孕期胎儿颜面轮廓超声对21-三体综合征的诊断价值

Diagnostic Value of Fetal Facial Contour Ultrasound in Early Pregnancy for Trisomy 21 Syndrome

目的:探究早孕期胎儿颜面轮廓超声对21-三体综合征的诊断价值。方法:选取2021年1月至2023年6月在本院经产前诊断并经染色体分析确诊胎儿为21-三体综合征的110例早孕期(孕11~13^(+6)周)孕妇作为病例组,另选取同期于我院进行常规产检且胎儿发育正常的120例早孕期(孕11~13^(+6)周)孕妇作为对照组。收集一般资料并进行胎儿颜面轮廓的超声检查。将早孕期胎儿颜面轮廓指标纳入多因素Logistic回归分析,分析超声诊断21-三体综合征的重要影响因素。应用受试者操作特征(ROC)曲线分析早孕期胎儿颜面轮廓指标诊断21-三体综合征的效能。采用Logistics回归分析不同颜面轮廓指标对早孕期胎儿21-三体综合征的诊断价值,建立回归方程y=1-1/(1+e^(-z))预测模型并进行验证。结果:病例组中胎儿的下颌-上颌线(MML)与颜面轮廓线(FPL)均表现为阳性,对照组胎儿均表现为“零”“阴性”(P<0.05);病例组胎儿的颈项透明层(NT)、鼻前组织厚度(PT)/鼻骨长度(NBL)、额-上颌角(FMF)、面部鼻额角(FNA)、额前空间距离(PSD)指标水平显著高于对照组(P<0.05),NBL、PT、额前空间比例(PFSR)、面下部角(IFA)、上颌-鼻根-下颌角(MNM)、上下颌面角(MMF)指标水平显著低于对照组(P<0.05)。多因素Logistic回归分析结果显示,早孕期胎儿颜面轮廓指标是超声诊断21-三体综合征的重要影响因素(P<0.05),且变量之间相互独立。ROC曲线分析结果显示,颜面轮廓指标均具有较高的诊断21-三体综合征的效能,且指标联合应用时,诊断21-三体综合征的AUC高达0.97,诊断效能最好。依据影响因素构建的预测模型区分度、准确度良好。不同颜面轮廓指标检测早孕期胎儿21-三体综合征的AUC内部验证前后分别为0.87(95%CI:0.81~0.92)和0.89(95%CI:0.82~0.96),灵敏度分别为89.71%和89.68%,特异度分别为91.57%和91.61%。结论:与健康胎儿相比,早孕期21-三体综合征胎儿经超声检查可见NT厚度、PT、PT/NBL、PSD、FMF较明显增加,NBL、PFSR、MMF、IFA及MNM显著减小,MML、FPL均表现为“阳性”,上述颜面轮廓指标对早孕期21-三体综合征胎儿具有较高的诊断价值。

Objective:To explore the diagnostic value of ultrasound examination of fetal facial contours in trisomy 21 syndrome in early pregnancy.Methods:From January 2021 to June 2023,a total of 110 pregnant women(11 to 13^(+6) weeks gestation)diagnosed with trisomy 21 syndrome by chromosome analysis were selected as the case group in our hospital.Meanwhile,120 pregnant women(11 to 13^(+6) weeks gestation)with normal fetuses undergoing routine check-ups during the same period were selected as the control group.General information was collected and ultrasound examinations of the fetal facial contour were performed.The facial contour index of fetus in early pregnancy was included in multi-factor Logistics regression analysis to analyze the important influencing factors of ultrasonic diagnosis of trisomy 21 syndrome.Receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of fetal facial contour in the diagnosis of trisomy 21 syndrome.Logistics regression was used to analyze the diagnostic value of different facial contour indexes for trisomy 21 syndrome of fetuses in early pregnancy.The regression equation y=1-1/(1+e^(-z))prediction model was established and verified.Results:The MML and FPL of the fetuses in the case group were positive,while the fetuses in the control group were“zero”and“negative”(P<0.05).The fetal levels of NT,PT/NBL,FMF,FNA and PSD in case group were significantly higher than those in control group(P<0.05),while the fetal levels of NBL,PT,PFSR,IFA,MNM and MMF were significantly lower than those in control group(P<0.05).Multivariate Logistic regression analysis showed that fetal facial contour index was an important factor for ultrasound diagnosis of trisomy 21 syndrome in early pregnancy(P<0.05),and the variables were independent of each other.ROC curve analysis results showed that facial contour indexes had high diagnostic efficacy,and the AUC for the diagnosis of trisomy 21 syndrome was as high as 0.97 when the indexes were combined,indicating the best diagnostic efficacy.The prediction model based on the influencing factors has good differentiation and accuracy.The AUC before and after internal validation for different facial contour indexes in detecting trisomy 21 syndrome in early pregnancy were 0.87(95%CI:0.81-0.92)and 0.89(95%CI:0.82-0.96),respectively.The sensitivity was 89.71%and 89.68%,and the specificity was 91.57%and 91.61%respectively.Conclusion:Compared with the healthy fetus,the ultrasonography of trisomy 21 syndrome fetus in early pregnancy showed significantly increased NT thickness,PT,PT/NBL,PSD,FMF angle,significantly decreased NBL,PFSR,MMF,IFA angle and MNM angle,MML and FPL were positive.The above facial contour indexes have high diagnostic value for the fetus with trisomy 21 syndrome in early pregnancy.