陈凤林教授指出:晚期流产的具体通过以下方法确诊为宫颈松弛：1、病史：诊断宫颈机能不全首先要依据一次或多次的晚期流产病史。 Professor Chenfenglin pointed out: The specific diagnosis of advanced abortion is cervical relaxation through the following methods: 1. History: Diagnosis of cervical insufficiency must first be based on one or more advanced abortion history.
2、妇科检查、扩宫试验：7号扩宫棒可顺利通过宫颈内口。 2, gynecological examination, palace expansion test: No. 7 palace expansion stick can pass through the cervix.
3, auxiliary examination: B Super(pregnant) cervical insufficiency can be seen in the early stage of the cervix shortening or funnel-shaped(fetal membrane funnel-shaped into the cervix).