Detecting RI and S/D of umbilicus artery with UCAN plays an important roles so that delivery mode could be decided correctly in clinic and complication of infant in perinatal period is reduced.

• 结论超声诊断脐带绕颈有较高的特异性及准确性，脐绕颈时脐动脉RI、S／D值检测对临床分娩方式的选择及降低围产儿不良结局的发生有指导意义。