The process of cervical insufficiency examination is as follows: 1. Through gynecological examination, after routine disinfection of the vulva, a speculum is inserted into the vagina and opened to find out whether the cervical shape is normal and whether the inner opening of the cervix is relatively loose. 2. Ultrasound examination is needed to find out the length of the cervix and if the length of the cervix is less than 3 cm, it is possible that the cervix is insufficiently functioning. In addition, the clinical history should be combined with the corresponding analysis, for example, the symptoms of sudden miscarriage in the middle of pregnancy may be cervical insufficiency, so the combination of clinical history, gynecological examination and laboratory tests can be a comprehensive analysis of cervical insufficiency.