Cervical canal length: structure, norm, pathology

There is no doubt in the uniqueness of the female body. Mother Nature has everything in great detail. The device of the woman’s body allows the fetus to form, which begins its journey with a set of cells, subsequently turning into an embryo, and already resembles a person by the beginning of the third trimester. After the fertilization of the egg, the body enters a new phase, the purpose of which is the development of a new life. The length of the cervical canal in this process plays an important role.

It is not without reason that doctors pay close attention to this parameter at the reception in the antenatal clinic. Fixing the length of the cervix allows you to timely detect the presence of a particular pathology, as well as take all necessary measures to avoid serious complications. But what length is considered to be the norm, and in which case is it a sign of deviation? Actually, this is the topic of this article.

General information

To begin with, we will reveal the essence of the concept of the cervical canal - what is it all about? In fact, this is the segment that connects the vagina to the cavity of the genital organ. In the language of doctors, it is called the pharynx. It is through it that the seminal fluid passes to fertilize the egg, as well as the discharge during menstruation.

The size of the channel is directly dependent on whether the girl gave birth or not. The standard diameter of the pharynx is not more than 3 mm. At the same time, if the girl has not yet become a mother, then at the gynecological examination the doctor will see a point, and for women who have already given birth - a gap. As for the length of the cervical canal, here are the dimensions:

• nulliparous girls - 40 mm;
• in mothers - up to 80 mm.

In the second pregnancy, the norm can be considered if during the examination the pharynx passes a finger. At the same time, the neck length should not be less than 20 mm. Otherwise, this clearly indicates isthmic-cervical insufficiency (ICI).

The role of the cervical canal during pregnancy

The main functions of the pharynx are as follows:

• This lumen connects the vagina and the uterine cavity, menstrual flow passes through it, which indicates the absence of pregnancy. But if the girl did not have the first menstrual bleeding (menarche), therefore, the problem lies in the obstruction of the cervical canal.
• The formation of cork mucosa over the entire length of the cervical canal during pregnancy. This substance assists in the promotion of male germ cells in the cavity of the genital organ. Mucus provides protection against infection, as it has bactericidal properties. During pregnancy, it hardens, and a plug forms, finally closing the passage into the uterus. Thus, a physical barrier is formed, which excludes the penetration of any pathogenic microorganisms into the organ cavity.
• At the stage of an increase in the genital organ, the channel becomes smaller (this is not a pathology) and denser. Such a measure avoids premature outflow of amniotic fluid.
• In the process of childbirth, the channel is able to stretch in order to miss the baby.

As for the cork, it remains for all 9 months, while a woman carries a child under the heart. And with the opening of the pharynx, she independently departs. But how is the length of the cervical canal determined by weeks of pregnancy and in a normal physiological state?

Cervicometry

This term should be understood as the technique of ultrasound examination of the cervical canal. It allows doctors to find out not only its length, but also other parameters. In addition, an ultrasound scan helps determine the size of the internal and external pharynx.

The examination itself is carried out using a transvaginal sensor, with which all channel parameters are found out. This procedure does not cause pain in women and is easily tolerated by them.

The methodology is based on the principle of reflection of outgoing ultrasonic waves from biological structures of various types. Typically, ultrasound can be performed not only in a hospital, but also during a visit to the clinic.

In addition, the length of the neck along the cervical canal can be determined during a planned visit by a pregnant woman to a doctor for a gynecological examination. The specialist reveals its size by touch. And in this way not only length is determined, but also density, localization, expansion.

Norm indicators

Normally, the cervical canal is in a closed state, which allows you to hold the fetus in the cavity of the genital organ throughout the gestation period. Typically, the condition of the pharynx is recorded during the standard diagnostic procedure. But if there is any suspicion, the doctor prescribes the patient an additional study, which will confirm the diagnosis or refute it.

Also, women will have to take all the necessary tests. This will allow doctors to compile an objective clinical picture of the current situation, both in relation to the woman herself and her child.

The length of the cervical canal begins to change from the 20th week of pregnancy and, starting from this period, doctors already record this parameter every seven days. This is done in order to timely detect deviations from the norm, if they occur.

Change in channel length by week of pregnancy

With the onset of the first trimester of pregnancy, the channel length is 40 mm, which fits into the normal range. In the II period of bearing a child, the channel begins to shorten, and the pharynx itself expands. At this time, a length of 35 mm is considered the norm. Before giving birth, at 36-37 weeks, the length of the canal becomes even less - up to 30 mm, which is also not a pathology. A week before delivery, this value becomes even slightly less, while the pharynx is expanded to 100 mm. A more accurate idea of ​​changing the channel length will provide the table below.

The table above clearly shows that at a period of 12 to 15 weeks of pregnancy, the length of the canal is almost the same as its length in girls outside this physiological state. Of course, subject to the physical health of the woman.

The length of the cervical canal begins to increase starting from the 16th week of pregnancy. And at 19 weeks it is already 39 mm, and by the 29th it reaches a maximum of 41 mm. In other words, the cervical canal begins to gradually increase from the second trimester of pregnancy. But then the size decreases - and all this is the norm.

Channel extension

Over the course of 9 months of bearing the baby, the length of the cervical canal during pregnancy normally increases and then decreases, and this is not a pathology. But what if the channel size does not match the average value for a certain period? Is this the norm or can this phenomenon be regarded as a pathology? To begin, consider the causes of lengthening of the cervical canal:

• anatomical structure of a congenital nature;
• frequent inflammatory processes of the organs of the female reproductive system;
• getting injured;
• surgical intervention.

Due to the elongated size of the channel, a violation of the process of fertilization and development of the fetus, including subsequent delivery, can occur. In addition, the uterine pharynx undergoes undesirable changes, and the placenta itself may not properly fix on the uterine wall. In this case, cases of postponed pregnancy are frequent due to the fact that the reproductive system is not yet ready for childbirth.

In addition, when the length of the cervical canal deviates from the norm, it has a solid structure. Therefore, it is poorly stretched and therefore does not ripen by the right time. In addition, the duration of contractions increases, which leads to a weakening of the female body and complication of delivery. As a rule, in such situations, resort to stimulation of labor.

Too long a channel should be attributed to pathology. This condition does not lead to anything good, and therefore requires the intervention of specialists. For this reason, studies are being conducted in the antenatal clinic.

Provocative factors

The length of the cervical canal changes throughout all 9 months of pregnancy. Moreover, hormones and a number of other reasons normally influence this process.

However, provoking factors contributing to the deviation of the length of the cervical canal at 12 weeks from the norm (or for any other period) cannot be ruled out. Some of them do not bode well:

• Disruption of the hormonal background. Biologically active substances provide pregnancy control. They also provide preparation of the reproductive system of the female body for labor. For this reason, the occurrence of an imbalance inevitably causes a deviation of the length of the cervical canal from the normal range.
• Cervical trauma during surgery. In particular, we are talking about abortion or previous birth. In this case, the cervix may become shorter or longer.
• Diseases of the reproductive system of an infectious nature.
• Features of the anatomical structure.
• Stress. Not without reason, experts recommend pregnant women to avoid strong excitement. It is important for any expectant mother to ensure peace, since a stable state helps maintain hormonal levels within normal limits. Stressful situations (especially severe ones) can provoke various pathologies in the development of the fetus.

For this reason, it is necessary to constantly monitor the length of the cervical canal during pregnancy. This will allow timely action to be taken.

Channel extension

In cases where the expansion of the cervical canal is detected in patients, they are sent to a hospital. The need for this solution is largely due to the fact that this symptom indicates a CPI. That is, the neck itself has already been opened ahead of schedule. The fruit, increasing in size, exerts even greater pressure on it. And if we are talking about multiple pregnancy, then this phenomenon is almost always observed due to the specifics of this situation.

To eliminate the pathology, drug therapy or a surgical method are used. With the help of medications, it is possible to bring the hormonal background back to normal, as well as eliminate the hypertonicity of the genital organ.

Pathology of an inflammatory nature

The impact of pathogenic microorganisms on the cervical canal contributes to the development of the inflammatory process. This condition is called endocervicitis. As a rule, inflammation is caused by the presence of a wound (along the entire length of the cervical canal or in a certain part of it). Microorganisms such as chlamydia and staphylococcus can cause a similar reaction, even if the canal is not injured.

The danger of endocervicitis is as follows:

• uterine hypertonicity;
• insufficient oxygen supply to the fetus;
• loosening of the membranes;
• premature onset of labor.

During the gynecological examination of the patient on the basis of the above symptoms, the specialist diagnoses endocervicitis. To determine the course of treatment, a smear is taken, which is tested in laboratory conditions. First you need to find out the type of pathogen and only then determine the drug to combat it.

Since pregnant women are not allowed to use all drugs, preference is given to local drugs: suppositories, capsules. The appointment of a particular external drug should be handled only by a highly qualified doctor. In addition, you should consider not only the type of pathogen, but also the duration of pregnancy.

Frightening diagnosis

In some cases, during the determination, the normal length of the cervical canal by the week of pregnancy or not, doctors can detect the presence of a polyp. Many girls are afraid of such a diagnosis.

However, in this case there are two development paths:

• True polyp. Often its presence causes problems with conception. For this reason, when planning a pregnancy, it should certainly be removed. After this, a woman needs to undergo drug therapy to avoid relapse.
• A pseudo-polyp develops only in expectant mothers. At the same time, the growth itself does not have any effect on the health and well-being of the woman and her child. And after childbirth, he independently resolves. The reason for the appearance of this neoplasm is a change in the hormonal background in the female body. Since he himself is eliminated, there is no need to resort to surgery, it is enough to treat it with any antiseptic.

At the same time, a true polyp can also be detected in pregnant women. Only in this case, he should not be disturbed before the birth of the child, only vigilant monitoring of his condition during routine examinations of the length of the cervical canal is necessary. This will prevent any complications in a timely manner. Only in the most severe cases, despite the special situation of the woman, surgery is prescribed when there is a threat to the life of the mother.

Conclusion

Inside each of us, all systems are combined into a single whole, which is called in one word - the body. Moreover, each of them consists of organs, and the effectiveness of all processes depends on their health. And pregnancy in this case is no exception.

What conclusion can be drawn from the foregoing? One thing is certain with certainty - determining the length of the cervical canal by weeks of pregnancy is a fundamental way to control this process. It is important to monitor the dynamics of changes in its length in order to timely identify pathology and begin an appropriate course of treatment, depending on the provoking factor.

This will keep the pregnancy until the end of the term, and the baby will be born completely healthy and happy to the joy of parents. It’s definitely not worth joking with your health, and even more so your own child.