子宫颈机能不全表现为无痛性的宫口开大，首次妊娠子宫颈机能不全的临床表现更为隐匿，对高危孕妇通过子宫颈超声检测可以早期识别可疑子宫颈机能不全。是否需要对所有中孕期孕妇进行超声子宫颈长度筛查各国意见不一致，但肯定的是普筛最重要的意义在于可发现首次妊娠即为早产的高危孕妇并可进行晚期流产和早产防治。关于孕期短子宫颈，有孕中期流产史或早产史但无子宫颈环扎术指征的女性，伴子宫颈缩短（≤25mm）可从子宫颈环扎术中获益；此外，针对短子宫颈病因中最重要的是排除感染因素导致的子宫颈改变。子宫颈环扎术后行超声子宫颈检测的意义在于依据具体病情的个体化决策。

Cervical insufficiency is often presented as painless dilation of the cervix，while the clinical manifestations of cervical insufficiency in the first pregnancy are more insidious. Cervical ultrasound detection for high-risk pregnant women can identify suspected cervical insufficiency at an early stage. There is no consensus among countries on the need for ultrasound cervical length screening for all women in their second trimester，but it is certain that the most important significance of universal screening is to detect high-risk women who are preterm in their first pregnancy and to prevent late abortion and preterm birth. Women with a history of second-trimester miscarriage or preterm birth but no reasonable indication of cervical cervix shortening（CL≤25mm）may benefit from cervical cerclage. In addition，the most important thing to target the cause of short cervix is to rule out the cervical changes caused by infectious factors. The significance of ultrasonic cervical examination after cervical cerclage lies in the individual decision-making according to the specific condition.