There is no national or international consensus on routine monitoring of cervical changes during pregnancy, and there are still difficulties with routine screening and effective post-screening interventions, both in terms of health economics and in terms of our interventions. So, who needs to be concerned about cervical changes and monitoring of the cervix? Again, cervical insufficiency describes a state of “incompetence” of the cervix. Theoretically, cervical length does not represent cervical function, but the correlation between a short cervix and miscarriage/preterm delivery is more certain. In other words, clinicians cannot determine incompetence based on the length of the cervix, but they can predict preterm labor. Coupled with the safety of ultrasound, the most common method of predicting preterm labor is still ultrasound cervical length monitoring during pregnancy. Transvaginal ultrasound (referred to as cervical ultrasound) is more reliable, that is, more reproducible and more accurate than the assessment of perineal and abdominal ultrasound measurements. However, even so, the measurement of cervical length can still vary and can be influenced by many factors, such as changes in the position of the mother, standing or lying down? For example, the “light hand” of the sonographer during the measurement? For example, whether or not the woman has emptied her bladder. Of course, the most important thing is the experience and training of the sonographer! Look at the following examples and you will be surprised how quickly the cervix can change its face! 2. Why not routinely screen or monitor cervical changes? Since cervical length can predict preterm labor, why not routinely screen or monitor cervical length during pregnancy? Up to now, this has not been recommended in national guidelines and authoritative literature, including Chinese preterm birth guidelines. The reason is, if screening reveals a short cervix is there any way we can deal with it? If there is no way to deal with it and it cannot guide clinical practice, then there is no need to spend physician energy and patient money to screen! The previous view was much less in favor of screening, but now because of the availability of methods that may be beneficial in preventing preterm labor, especially with the new progesterone and cervical tor, it has been suggested that even for those without risk factors, shouldn’t a cervical length screening be performed? No consensus has been reached yet. 3. Which cases are at high risk and require attention to the cervix? If cervical length is a predictor of spontaneous preterm labor, then all people at risk for spontaneous preterm labor should be screened for cervical length. However, there are many groups at risk for preterm labor, including pregnant women who smoke, are underweight, have poor economic conditions, have periodontal disease, have fetal malformations, are anemic, are younger than 18 or older than 40, have placenta praevia, are anxious or depressed, have recurrent bleeding during pregnancy, and so on. Our clinical focus is more on the risk factors for cervical insufficiency, such as history of mid-pregnancy miscarriage, history of preterm delivery, history of cervical surgery or trauma (such as cervical conization or multiple hysteroscopies), history of multiple miscarriages, uterine malformations, etc. Of course, multiple pregnancies are also a high-risk group for preterm delivery that we are particularly concerned about. In conclusion, medical technology is constantly evolving, and we can only keep changing according to the development of technology and current research evidence, and of course taking into account the distribution of health resources in each region.