三维超声部分肢体体积预测胎儿出生体重的一致性研究

目的:研究胎儿三维容积超声部分肢体体积预测胎儿出生体重的一致性方法:选取2018年10月至2019年12月于我院行超声检查后3天内生产的70例胎儿为研究对象,超声规范化测量胎儿二维超声参数:双顶径、头围、腹围、股骨长度,生成二维超声参数生成的估计胎儿体重(estimated fetal weight,EFW),记录为EFW 1。三维容积超声测量部分肢体体积:上臂中段50%的体积(fractional arm volume,AVol)和大腿中段50%的体积(fractional thigh volume,TVol)。二维超声参数联合AVol生成的估计胎儿体重,记录为EFW 2;二维超声参数联合TVol生成的估计胎儿体重,记录为EFW 3。比较三种方法的胎儿体重预测值与实际出生体重之间的误差。结果:本组AVol和TVol取值范围分别为(29.9~43.2)ml、(48.7~72.4)ml,均数±标准差分别为(36.7±4.8)ml、(59.8±7.4)ml,AVol和TVol与出生体重的相关性显著(r=0.736、0.804,P<0.05)。Bland-Altman图示EFW 2与出生体重一致性分析的95%一致性范围为(-493~285)g,95.7%的点在范围内;EFW 3的95%一致性范围为(-397~381)g,97.1%的点在范围内,均有较好的一致性。在体重预测值中,EFW 2大于EFW 3,但小于EFW 1,三者间差异无统计学意义(P>0.05)。EFW 2和EFW 3的系统误差、随机误差均小于EFW 1,但差异无统计学意义(P>0.05)。EFW 2和EFW 3的绝对误差、绝对误差绝对值均小于EFW 1,差异有统计学意义(P<0.05)。EFW 2和EFW 3的相对误差≤5%、≤10%的比例,及绝对误差≤100g、≤250g的比例均高于EFW 1。结论:临产前胎儿的TVol、AVol均与出生体重有较密切的正相关关系,预测一致性好,以TVol和AVol为基础所得的胎儿体重预测准确性高于传统二维超声方法,为临床提供了重要价值。

Study on the consistency and accuracy of three-dimensional ultrasonic volume in predicting fetal birth weight

Objective:to study the consistency of fetal three-dimensional volume ultrasound partial limb volume in predicting fetal birth weight Methods:70 fetuses born within 3 days after ultrasound examination in our hospital from October 2018 to December 2019 were selected as the research objects,the two-dimensional ultrasonic parameters of fetus were measured by ultrasonic normalization:double apex diameter,head circumference,abdominal circumference and femur length,the estimated fetal weight(EFW)generated by two-dimensional ultrasound parameters was recorded as EFW1.Three dimensional volumetric ultrasound was used to measure the volume of partial limbs:50%of the volume of the middle arm(AVol)and 50%of the volume of the middle thigh(TVol).The estimated fetal weight generated by two-dimensional ultrasound parameters combined with avol was recorded as EFW2;The estimated fetal weight generated by two-dimensional ultrasound parameters combined with tvol was recorded as EFW3.The errors between the predicted fetal weight and the actual birth weight were compared.Results:The values of avol and tvol were(29.9-43.2)ml and(48.7-72.4)ml,respectively±The standard deviations were(36.7±4.8)ml、(59.8±7.4)ml,Avol and tvol were significantly correlated with birth weight(r=0.736,0.804,P<0.05).The 95%agreement between EFW 2 and birth weight was(from-493 to 285)g,and 95.7%of the points were in the range;The 95%consistency range of EFW 3 was(from-397 to 381)g,and 97.1%of the points were in the range.EFW 2 was higher than EFW 3 in the prediction of body weight,But EFW 2 is smaller than EFW 1,There was no significant difference among them(P>0.05).The systematic error and random error of EFW 2 and EFW 3 were less than that of EFW 1,but the difference was not statistically significant(P>0.05).The absolute error and absolute value of absolute error of EFW 2 and EFW 3 were less than that of EFW 1(P<0.05).The proportion of relative error≤5%,≤10%and absolute error≤100 g,≤250 g of EFW 2 and EFW 3 are higher than that of EFW 1.Conclusion:The TVol and AVol of fetus before delivery had a close positive correlation with birth weight,and the prediction consistency was good,The accuracy of fetal weight prediction based on tvol and avol is higher than that of traditional two-dimensional ultrasound,which provides important value for clinical use.