早孕期超声相关参数预测胚胎妊娠结局价值的分析

Prediction value of first trimester ultrasound parameters for pregnancy outcome

目的:分析早孕期超声相关参数在预测胚胎妊娠结局中的价值。方法:收集1651例孕妇,记录孕7周前的胎心率、平均妊娠囊内径(mean gestation sac diameter,MSD)及头臀长数据,并在孕13周前进行超声检查以明确胚胎是否继续存活,根据结果将其分为存活组(1556例)及自然流产组(95例),比较2组间的早孕期超声参数间的差异。结果:1651例孕妇在孕13周前的自然流产率为5.85%,其中孕7周前胎心率≤80次/min者的自然流产率达100%;胎心率为90~130次/min者的自然流产率明显下降(2.51%)(P<0.05),且随着胎心率的升高其胎儿存活率上升;但当胎心率>130次/min时,胚胎流产率上升(2.79%)。孕7周前MSD-头臀长≤5 mm者的流产率为57.14%,MSD-头臀长越大,胚胎的存活率越高。受试者操作特征(receiver operating characteristic,ROC)曲线分析结果显示,用孕7周前胎心率预测胚胎不良妊娠结局的曲线下面积(area under curve,AUC)为0.870(P<0.05),胎心率97次/min为其最佳临界值,此时的预测灵敏度、特异度、阳性预测值(positive predictive value,PPV)及阴性预测值(negative predictive value,NPV)分别为81.05%、99.04%、83.7%、98.8%;用孕7周前MSD-头臀长进行预测时,AUC为0.780(P<0.05),MSD-头臀长11.3 mm是其最佳临界值,此时的预测灵敏度、特异度、PPV及NPV分别为56.84%、89.01%、24.00%、97.10%;而将胎心率结合MSD-头臀长可提高胚胎妊娠结局的预测价值,AUC为0.922(P<0.05)。结论:本组孕13周前的自然流产率为5.85%,孕7周前超声测量的胎心率为97次/min及MSD-头臀长为11.3 mm是预测胚胎妊娠结局的最佳临界值,胎心率和MSD-头臀长越小,胚胎发生自然流产的风险越高。

Objective:To explore the predictive value of ultrasonographic parameters in the first trimester pregnancy outcomes.Methods:A total of 1651 pregnancy were enrolled,and ultrasonographic parameters including fetal heart rate(FHR),mean gestation sac diameter(MSD)and crown to rump length(CRL)at or before 7 weeks′gestational age were measured,and the sonogram obtained at or before 13 weeks′gestation to determine the embryo survived or demise.It revealed that 1556 cases were classified into ongoing pregnancy group and 95 cases were into spontaneous abortion group.Results:Before 13 weeks′,the spontaneous abortion rate was 5.85%in the study.Pregnancy loss occurred in all the cases with the FHR slower than or equal to 80 bpm(100%),while in fetal with FHR>90 bpm decreased significantly(2.51%).The survival rate increased with the increase of FHR when FHR≤130 bpm,while the fetal demise rate increased as FHR>130 bpm(2.79%).The spontaneous abortion rate was 57.14%as MSD-CRL≤5 mm.The bigger the MSD-CRL was,the higher the survival rate was.Receiver operating characteristic(ROC)curve analysis demonstrated that AUC of FHR=97 bpm for poor pregnancy outcome was 0.870(P<0.05),while sensitivity,specificity,PPV and NPV were 81.05%,99.04%,83.7%and 98.8%respectively.When MSD-CRL was taken as 11.3 mm,AUC for prediction of spontaneous abortion was 0.780(P<0.05),with sensitivity,specificity,PPV and NPV values were 56.84%,89.01%,24.00%and 97.10%respectively.When the combination of FHR and MSD-CRL,the AUC for prediction of spontaneous abortion was 0.922(P<0.05).Conclusions:The spontaneous abortion rate was 5.85%in the study.The cut-off value for FHR and MSD-CRL to predict abortion are 94 bpm and of 11.3 mm,respectively.The lower the fetal heart rate and the smaller MSD-CRL diameter are,the higher the spontaneous abortion rate will occur.