孕晚期产前超声定量评估脐带螺旋指标对脐带扭转的预测价值

Prenatal ultrasound in the third trimester quantitatively evaluated the predictive value of cord coiling indexes on umbilical cord torsion

目的探讨孕晚期产前超声定量评估脐带螺旋指标对脐带扭转的预测价值。方法回顾性分析2020年12月至2021年8月在宁波市妇女儿童医院超声科行常规产前超声检查的528名孕晚期(孕28周至分娩前)孕妇的临床资料,根据其脐静脉–静脉螺距(vein-vein pitch,V-V Pitch)值和脐带直径计算产前脐带螺旋指数(antenatal umbilical coiling index,aUCI)和L/D脐带螺距(length/diameter pitch,L/D Pitch)值;随访产后是否有脐带扭转。按是否发生脐带扭转分为脐带扭转组和无扭转组,比较两组孕妇的V-V Pitch值、aUCI和L/D Pitch值差异有无统计学意义,并绘制V-V Pitch值、aUCI和L/D Pitch值预测脐带扭转的受试者操作特征(receiver operating characteristic,ROC)曲线。结果脐带扭转组与无扭转组的V-V Pitch值、aUCI和L/D Pitch值差异均有统计学意义(P<0.05),3种指标对脐带扭转均有预测作用,其中V-V Pitch值和aUCI是等价的,ROC曲线下面积(area under the curve,AUC)分别为0.873、0.873和0.848,截断值分别≤33.00mm,>0.30coils/cm,≤2.40coils/cm,阳性预测值分别为24.10%、24.10%和21.40%,阴性预测值分别为99.70%、99.70%和99.70%。结论产前超声测量V-V Pitch值、aUCI和L/D Pitch值对预测脐带扭转有一定作用,其阴性预测值较高但阳性预测值较低,更适合用来排除脐带扭转。

Objective To investigate the predictive value of prenatal ultrasoundquantitative assessment of umbilical cord coiling index on umbilical cord torsion in third trimester of pregnancy.Methods A retrospective analysis of the clinical data of pregnant women undergoing routine prenatal ultrasound examination in the ultrasound department of Ningbo Women and Children’s Hospital from December 2020 to August 2021 in the third trimester(28 weeks gestation to before delivery)was performed,among which 528 cases met the enrollment requirements,according to their umbilical vein-vein pitch(V-V Pitch)value and umbilical cord diameter,antenatal umbilical coiling index(aUCI)and length/diameter pitch(L/D Pitch)value were calculated.Follow-up for cord torsion after delivery.The above cases were statistically analyzed,and the receiver operating characteristic(ROC)curve of V-V Pitch value,aUCI and L/D Pitch value predicted umbilical cord torsion was plotted.Results There were significant differences in V-V Pitch values,aUCI and L/D Pitch values between cord torsion group and no torsion group(P<0.05),and all three indexes had predictive effects on cord torsion,among which V-V Pitch value.The area under the curve(AUC)was 0.873,0.873 and 0.848,and the cut-off values were≤33.00 mm,>0.30 coils/cm,≤2.40 coils/cm,positive predictive values were 24.10%,24.10%,and 21.40%,and negative predictive values were 99.70%,99.70%,and 99.70%,respectively.Conclusion Prenatal ultrasound measurements of V-V Pitch value,aUCI and L/D Pitch value have a certain effect on predicting umbilical cord torsion,and the negative predictive value is higher but the positive predictive value is low,which is more suitable for excluding umbilical cord torsion.