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1 651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（1 556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：1 651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 1 651 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 1 556 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.