Transvaginal cervicitometry of the cervix: how it is conducted and how often do

, medical expert
Last reviewed: 19.10.2021

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Cervicometry means a procedure designed to determine the length of the cervix. For this purpose, a special ultrasound device is used. These data need to be known in order to further predict the course of pregnancy and to understand how the fetus is retained inside the uterus. If the indicators are normal, then there is no cause for concern. If the length is shorter than required, there is a risk of serious pathologies, in particular, premature birth. Cervicometry provides an opportunity to identify in a timely manner many pathologies that arise during pregnancy and prevent a number of dangerous pathologies. Knowing the results, you can take the necessary measures in time and prescribe the required treatment, which will prevent the risk.

What is cervicometry in pregnancy?

This is one of many diagnostic procedures that is used to determine the risk of developing possible pathologies and complications. Can be carried out in two ways - internal and external. Each method has its own advantages and disadvantages, so the choice is always left for the doctor. Most specialists are inclined to believe that transvaginal cervicemetry should be used to make the results more accurate. 

For an external method, the length of the cervix is recorded using a traditional ultrasound device. Measure through the peritoneum. With a filled bladder, it becomes possible to more accurately probe the uterus, neck.

There is also a method that is more accurate - the transvaginal method. It is carried out with an empty bladder to ensure greater accuracy of the results. With the accumulation of urine, it is not possible to fully view the entire picture and take measurements. The study is based on the use of a special transvaginal sensor, which is injected directly into the vagina. The cervix is inspected, important indicators are measured. It is absolutely unimportant for a doctor how to use it when performing measurements, the very result is important.

Scheduled examination includes the conduct of ultrasound, during which measurements are taken (18-22 weeks). Usually this is enough, but if there is a risk of development of ICI, previous miscarriages and premature births, miscarriages, then it is necessary to conduct the study in a transvaginal way. If the indicators do not correspond to the norm, urgent measures must be taken, otherwise there is a risk of interruption.

Is Cerviometetry Harmful?

Manipulation is harmless for the fetus and mother, absolutely painless. Ultrasound exposure for safety is minimized. This was achieved by reducing the power of the waves and shortening the duration of the procedure. A woman absolutely does not need to worry, because all the nuances in modern equipment have long been taken into account. 

Specialists use the device in a special energy mode, in which the impact is limited, which leads to the limitation of acoustic power, as a result of which there is no additional influence.

Indications for the procedure

The procedure is carried out, first of all, when it occurs on premature birth, or they were observed earlier, with an increased likelihood of miscarriages. It is performed with abnormal development of the uterus, for the diagnosis of ICI. A procedure is mandatory for those who have several babies, or twins. For insurance, it is carried out if the woman has undergone surgery interventions of any kind or orientation: whether they are preventive, for the purpose of treatment or diagnosis. Regular measurements are carried out to control the condition of scars, uterine sutures.

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In the process of preparing for cervicometry, no action is required. It is only necessary to empty the bladder if a transvaginal method is used, and to preserve its fullness in an external study. This is necessary in order to obtain the most accurate results. No further training is required, since the physician conducting the study will do everything else necessary. Do not even worry about the results: the specialist will make a conclusion and give it to the obstetrician-curator.

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Who to contact?

Technique of the cervicometry

First the patient should completely empty, then lie down in the lithotomy position (traditionally settle on the gynecological chair). The essence of the procedure consists in introducing a special sensor into the vaginal environment, which makes it possible to perform the examination with the necessary measurements, fixes the result and displays the image on the computer.

Each measurement lasts an average of 2-3 minutes. Approximately 1% the size of the cervix can vary depending on the contractions of the uterus. If the indicators vary, the shortest option is taken into account. In the second trimester the fetus is mobile, and the indices vary (this depends on the position of the fetus). The most variable results are in the area of the uterus day and in the transverse position of the fetus.

There is another method for assessing the size of the uterus, during which measurements are performed transabdominally. This is an external method. But this can be called visual assessment rather than cervicometry. The indicators obtained with this method of measurement are unreliable, they differ significantly from those in reality. The error is 0.5 cm or more, which is important.

Cervicometry of the cervix

Know the size of the uterus is needed to ensure successful delivery. From the size in the first place depends the very course of pregnancy, the ability to bear the child. If the cervix is shortened, it can not withstand the pressure of the fetus and begin to prematurely open. This usually results in miscarriage, spontaneous abortion, premature birth.

By length, you can also determine the approach of birth. The closer to childbirth, the shorter the birth canal becomes, and the smaller the size of the neck. This process is natural and normal. At each stage of gestation, the indicators differ. 

Measurements are carried out by external or internal means. Only the internal method is accurate. Immediately before birth, the size of the cervix reaches 1 cm, and it gradually begins to open. All pregnancy, the cervix is covered by a slimy plug, which disappears after the opening process begins. Before birth, this is normal, but this process can begin at any time, which does not correspond to the norm and is due to the insufficient size of the neck. Control the size you need throughout the entire pregnancy, in order to be able to take the necessary measures in a timely manner. In addition, with the help of cervicometry, it is possible to determine the length of all those organs that are related to the process of childbirth. You can also determine the beginning of the disclosure, if it comes prematurely. Often there are cases that the length of the cervix is normal, and its opening is already happening. In this case, you can take timely measures that will save the child.

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Transvaginal cervicemetry

The method is internal, it gives an opportunity to obtain meaningful information regarding the length of the cervical canal. For this, a transvaginal sensor is used. The bladder should be empty. Then the lap falls on the chair, the sensor is inserted into the vaginal cavity. An image is displayed on the monitor. Manipulation is performed several times, usually three times, which makes it possible to exclude the possibility of error. The average duration of one measurement is a few minutes. The smallest indicator is taken into account. If the result is doubtful, a slight pressure is applied to the lower abdomen for 15 seconds, then the measurements are repeated.

Some experts resort to the use of electronic-digital calipers, which make it possible to measure the size of the pharynx. It is also necessary to take into account individual characteristics. Thus, the rates of the norm for primiparous and re-parenting are significantly different.

Cervicometry in dynamics

Sometimes it takes measurements in dynamics. This need arises if seams are applied to the neck and they need control if the cervical canal is widened or the fetal membranes penetrate it. Indicators must be taken into account if there were earlier premature births, surgical interventions. They are insured for the first-born, or in the event that information is not enough. In dynamics, indicators are measured once every 14 days.


How often do cerviometrics?

If there is a need for regular measurements, they are produced at intervals of 14 days. This situation relates to 15% of pregnant women. Usually in the dynamics of indicators are measured, starting at 15 weeks. In the absence of pathologies, the procedure is carried out once, at a period of 20-24 weeks.

Normal performance

There are no uniform indicators of the norm. They vary considerably and depend on the period, position of the fetus, and also whether pregnancy is first or repeated. There are many additional factors that also affect the rates of the norm. If the measurements are made at week 20, the norm values will be 40 mm, at 34 - they will decrease to 34 mm.



Many women leave positive reviews. First, they note that the procedure is painless. Secondly, the big plus is that the results can be obtained fairly quickly and do not torment yourself with apprehensions. Or, on the contrary, if a pathology is found, the necessary measures can be taken in a timely manner. The future child had no influence.

There are reviews when this procedure was made non-pregnant. This is also possible, for the diagnosis, for the treatment of many diseases. The matter is that the cervicometry is carried out not only for realization of measurements. You can get a picture of the cavity, see the walls, tissues, analyze the cervical fluid (daily measurements), which is of great diagnostic value. 

Translation Disclaimer: The original language of this article is Russian. For the convenience of users of the iLive portal who do not speak Russian, this article has been translated into the current language, but has not yet been verified by a native speaker who has the necessary qualifications for this. In this regard, we warn you that the translation of this article may be incorrect, may contain lexical, syntactic and grammatical errors.

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