超声测量早孕期胎儿心胸比预测重型α地中海贫血的价值

Value of cardiothoracic ratio measured by ultrasound for prediction of severeα-thalassemia in the first trimester pregnancy

目的探讨超声测量孕11~13^(+6)周胎儿心胸横径比预测重型α地中海贫血(以下简称α地贫)的价值。方法回顾性分析孕11~13^(+6)周单胎孕妇的449例胎儿,依据父母双方或胎儿的α地贫基因检测结果分为对照组(正常胎儿,311例)、轻型组(轻型α地贫胎儿,87例)、重型组(重型α地贫胎儿,51例),测量头臀径(CRL)、心胸横径比(CTR)、胎盘厚度(PT)、颈后透明层厚度(NT),比较组间的差异。通过构建受试者工作特征(ROC)曲线计算曲线下面积(AUC),确定各指标预测重型α地贫的最佳诊断界值、敏感度、特异度。结果3组之间的孕妇年龄、胎儿CRL相比较,差异无统计学意义(P>0.05)。重型组胎儿CTR、PT、NT值分别为0.53±0.04、(18.5±4.7)mm、(2.1±1.2)mm,明显高于轻型组和对照组[0.44±0.11、(13.2±2.3)mm、(1.6±0.5)mm;0.38±0.04、(13.0±2.1)mm、(1.4±0.6)mm],差异有统计学意义(P<0.01)。根据ROC曲线,CTR、PT、NT预测重型α地贫的曲线下面积分别是0.995、0.783、0.746,诊断界值分别是0.48、16.5 mm、1.8 mm。敏感度分别为98.0%、62.7%、60.8%,特异度分别为97.2%、80.6%、80.3%。结论早孕期CTR预测重型α地贫的价值高于PT、NT,应当重视、推广,更好发挥其临床应用价值。

Objective To evaluate the value of cardiothoracic ratio measured by ultrasound for prediction of severeα-thalassemia in 11-13^(+6) weeks.Methods A total of 449 fetuses of singleton pregnant women from 11 to 13^(+6) weeks were retrospectively analyzed.According to the results ofα-thalassemia gene detection of both parents or fetuses,they were divided into three groups,control group(n=311),mildα-thalassemia group(n=87)and severeα-thalassemia group(n=51).Crown-rump length(CRL),cardio thoracic ratio(CTR),placenta thickness(PT)and nuchal translucency(NT)were measured.The differences among the 3 groups were compared,and tested by t-test.The receiver operating characteristic curve(ROC)curves of fetal CTR,PT and NT for predict fetal seversα-thalassemia were drawn,and the area under ROC curve(AUC)were calculated.The optimal diagnostic threshold,sensitivity and specificity of each index for predicting severeα-thalassemia were determined by ROC.Results There was no significant difference in maternal age and fetal CRL among the three groups(P>0.05).The CTR,PT and NT[0.53±0.04,(18.5±4.7)mm and(2.1±1.2)mm]in severe group were significantly higher than those in mild group and control group[0.44±0.11,(13.2±2.3)mm and(1.6±0.5)mm;0.38±0.04,(13.0±2.1)mm and(1.4±0.6)mm],the differences were statistically significant(P<0.01).According to the ROC curve,AUC predicted by CTR,PT and NT for severeα-thalassemia were 0.995,0.783 and 0.746;and the diagnostic cutoff values were 0.48,16.5 mm and 1.8 mm,respectively.The sensitivities were 98.0%,62.7%and 60.8%;and the specificities were about 97.2%,80.6%and 80.3%,respectively.Conclusion The value of CTR in predicting severeα-thalassemia in early pregnancy is higher than that of PT.NT,CTR should be emphasized and popularized so as to give full play to its clinical value.