Screening for the first trimester of pregnancy is over, time passes, the belly grows, and new worries arise.
Have you heard or read somewhere about isthmic-cervical insufficiency (ICI), premature birth, ultrasound of the cervix and now you don’t know whether this threatens you and whether you need such a study, and if necessary, when?
In this article I will try to talk about such a pathology as ICN, about modern methods its diagnosis, the formation of a high-risk group for premature birth and treatment methods.

Premature births are those that occur during pregnancy from 22 to 37 weeks (259 days), starting from the first day of the last normal menstruation with regular menstrual cycle, while the fetal body weight ranges from 500 to 2500 g.

The frequency of premature births in the world in recent years is 5–10% and, despite the emergence of new technologies, is not decreasing. And in developed countries it is increasing, primarily as a result of the use of new reproductive technologies.

Approximately 15% of pregnant women are at high risk for premature birth even at the stage of collecting anamnesis. These are women who have a history of late miscarriages or spontaneous premature births. There are about 3% of such pregnant women in the population. In these women, the risk of recurrence is inversely related to the gestational age of the previous preterm birth, i.e. The earlier the premature birth occurred in the previous pregnancy, the higher the risk of recurrence. In addition, this group can include women with uterine anomalies, such as a unicornuate uterus, a septum in the uterine cavity, or trauma, surgical treatment of the cervix.

The problem is that 85% of preterm births occur in 97% of women in the population for whom this is their first pregnancy, or whose previous pregnancies ended in birth at full term. Therefore, any strategy aimed at reducing preterm birth that targets only a group of women with a history of preterm birth will have very little impact on general level premature birth.

The cervix plays a very important role in maintaining pregnancy and the normal course of labor. Its main task is to serve as a barrier that protects the fetus from being pushed out of the uterine cavity. In addition, the glands of the endocervix secrete special mucus, which, when accumulated, forms a mucus plug - a reliable biochemical barrier to microorganisms.

“Cervical ripening” is a term used to describe the rather complex changes that occur in the cervix related to the properties of the extracellular matrix and the amount of collagen. The result of these changes is the softening of the cervix, its shortening up to smoothing and expansion cervical canal. All these processes are normal during full-term pregnancy and are necessary for the normal course of labor.

For some pregnant women, due to various reasons“Cervical ripening” occurs ahead of time. Barrier function the cervix decreases sharply, which can lead to premature birth. It is worth noting that this process has no clinical manifestations and is not accompanied by pain or bleeding from the genital tract.

What is ICN?

Various authors have proposed a number of definitions for this condition. The most common is this: ICI is an insufficiency of the isthmus and cervix, leading to premature birth in the second or third trimester of pregnancy.
or something like that : ICI is a painless dilatation of the cervix in the absence of
uterine contractions, leading to spontaneous interruption
pregnancy.

But the diagnosis must be made even before the termination of pregnancy occurs, and we don’t know whether it will happen. Moreover, most pregnant women diagnosed with ICI will deliver at term.
In my opinion, ICI is a condition of the cervix in which the risk of preterm birth in a given pregnant woman is higher than the general population.

IN modern medicine, the most reliable way to assess the cervix is transvaginal ultrasound with cervicometry - measuring the length of the closed part of the cervix.

Who is indicated for cervical ultrasound and how many times?

Here are the recommendations from https://www.fetalmedicine.org/ The Fetal Medicine Foundation:
If a pregnant woman is among those 15% with a high risk of preterm birth, then such women are shown an ultrasound of the cervix every 2 weeks from the 14th to the 24th week of pregnancy.
For all other pregnant women, a single ultrasound of the cervix is ​​recommended at 20-24 weeks of pregnancy.

Cervicometry technique

Woman empties bladder and lies on the back with bent knees (lithotomy position).
The ultrasound probe is carefully inserted into the vagina towards the anterior fornix so as not to place excessive pressure on the cervix, which could artificially increase the length.
A sagittal view of the cervix is ​​obtained. The mucous membrane of the endocervix (which can be either increased or decreased echogenicity compared to the cervix) serves as a good guide to determine the true position of the internal os and helps to avoid confusion with the lower segment of the uterus.
The closed part of the cervix is ​​measured from the external os to the V-shaped notch of the internal os.
The cervix is ​​often curved and in these cases the length of the cervix, considered as a straight line between the internal and external os, is inevitably shorter than the measurement taken along the cervical canal. From a clinical point of view, the measurement method is not important, because when the cervix is ​​short, it is always straight.

Each test should be completed within 2-3 minutes. In about 1% of cases, the length of the cervix may change depending on uterine contractions. In such cases, the lowest values ​​should be recorded. In addition, the length of the cervix in the second trimester may vary depending on the position of the fetus - closer to the fundus of the uterus or in the area lower segment, in a transverse position.

You can evaluate the cervix transabdominally (through the abdomen), but this is a visual assessment, not cervicometry. The length of the cervix with transabdominal and transvaginal access differs significantly by more than 0.5 cm, both up and down.

Interpretation of research results

If the length of the cervix is ​​more than 30 mm, then the risk of premature birth is less than 1% and does not exceed the general population. Such women are not indicated for hospitalization, even in the presence of subjective clinical data: pain in the uterus and minor changes in the cervix, heavy vaginal discharge.

• If a shortening of the cervix of less than 15 mm in a single pregnancy or 25 mm in a multiple pregnancy is detected, urgent hospitalization and further management of the pregnancy in a hospital setting with the possibility of intensive care for newborns. The probability of delivery within 7 days in this case is 30%, and the probability of premature birth before 32 weeks of pregnancy is 50%.

• Shortening of the cervix to 30-25 mm during a singleton pregnancy is an indication for consultation with an obstetrician-gynecologist and weekly ultrasound control.

• If the length of the cervix is ​​less than 25 mm, a conclusion is issued: “ECHO signs of ICI” in the 2nd trimester, or: “Given the length of the closed part of the cervix, the risk of premature birth is high” in the 3rd trimester, and a consultation with an obstetrician-gynecologist is recommended for deciding whether to prescribe micronized progesterone, perform cervical cerclage or install an obstetric pessary.

Once again, I want to emphasize that the detection of a shortened cervix during cervicometry does not mean that you will definitely give birth ahead of time. This is exactly what we're talking about high risk.

A few words about the opening and shape of the internal pharynx. When performing an ultrasound of the cervix, you can find various shapes internal os: T, U, V, Y - shaped, moreover, it changes in the same woman throughout pregnancy.
With ICI, along with shortening and softening of the cervix, its dilatation occurs, i.e. expansion of the cervical canal, opening and changing the shape of the internal os is one process.
A large multicenter study conducted by FMF showed that the shape of the internal os itself, without shortening the cervix, does not statistically increase the likelihood of preterm birth.

Treatment options

Two methods of preventing premature birth have been proven effective:

• Cervical cerclage (suturing the cervix) reduces the risk of labor before 34 weeks by about 25% in women with a history of preterm labor. There are two approaches to treating patients with previous preterm birth. The first is to perform cerclage on all such women shortly after 11-13 weeks. The second is to measure the length of the cervix every two weeks from 14 to 24 weeks, and apply sutures only if the length of the cervix becomes less than 25 mm. The overall rate of preterm birth is similar with both approaches, but the second approach is preferred because it reduces the need for cerclage by approximately 50%.

If a short cervix (less than 15 mm) is detected at 20-24 weeks in women with a clear obstetric history, cerclage can reduce the risk of preterm birth by 15%.
Randomized studies have shown that in the case of multiple pregnancies, when the cervix is ​​shortened to 25 mm, cervical cerclage doubles the risk of premature birth.

• Prescribing Progesterone from 20 to 34 weeks reduces the risk of childbirth before 34 weeks by approximately 25% in women with a history of premature birth, and by 45% in women with an uncomplicated history, but identified shortening of the cervix to 15 mm. A study was recently completed that showed that the only progesterone that can be used for a short cervix is ​​micronized vaginal progesterone at a dose of 200 mg per day.

• Multicenter studies of the effectiveness of using a vaginal pessary are currently ongoing. A pessary, which consists of flexible silicone, is used to support the cervix and change its direction towards the sacrum. This reduces the load on the cervix due to reduced pressure from the fertilized egg. You can read more about the obstetric pessary, as well as the results of the latest research in this area

The combination of cervical sutures and a pessary does not improve effectiveness. Although the opinions of various authors differ on this matter.

After suturing the cervix or with an obstetric pessary in place, ultrasound of the cervix is ​​not advisable.

See you in two weeks!

Among the various causes of miscarriage, isthmic-cervical insufficiency (ICI) occupies an important place. If it is present, the risk of miscarriage increases almost 16 times.

The overall incidence of ICI during pregnancy ranges from 0.2 to 2%. This pathology is the main cause of miscarriage in the second trimester (about 40%) and premature birth - in every third case. It is detected in 34% of women with habitual spontaneous abortion. According to most authors, almost 50% of late pregnancy losses are caused by isthmic-cervical incompetence.

In women with a full-term pregnancy, labor with ICI often has a rapid nature, which negatively affects the condition of the child. In addition, rapid labor is often complicated by significant ruptures. birth canal accompanied by massive bleeding. ICN - what is it?

Definition of the concept and risk factors

Isthmic-cervical insufficiency is a pathological premature shortening of the cervix, as well as expansion of its internal os (muscular “obturator” ring) and the cervical canal as a result of increased intrauterine pressure during pregnancy. This can cause prolapse of the membranes in the vagina, their rupture and loss of pregnancy.

Reasons for the development of ICN

In accordance with modern ideas, the main causes of cervical inferiority are three groups of factors:

1. Organic - the formation of scar changes after traumatic injury to the cervix.
2. Functional.
3. Congenital - genital infantilism and uterine malformations.

The most common provoking factors are organic (anatomical and structural) changes. They may arise as a result of:

• cervical ruptures during childbirth with a large fetus, and;
• and removing the fetus by the pelvic end;
• rapid labor;
• application of obstetric forceps and vacuum extraction of the fetus;
• manual separation and release of placenta;
• carrying out fruit-destroying operations;
• artificial instrumental abortions and;
• operations on the cervix;
• various other manipulations, accompanied by its instrumental expansion.

The functional factor is presented:

• dysplastic changes in the uterus;
• ovarian hypofunction and increased levels of male sex hormones in a woman’s body (hyperandrogenism);
• increased levels of relaxin in the blood in cases of multiple pregnancy, induction of ovulation by gonadotropic hormones;
• long-term chronic or acute inflammatory diseases of the internal genital organs.

Risk factors also include age over 30 years, overweight and obesity, and in vitro fertilization.

In this regard, it should be noted that the prevention of ICI consists of correcting the existing pathology and excluding (if possible) the causes of organic changes in the cervix.

Clinical manifestations and diagnostic possibilities

It is quite difficult to make a diagnosis of isthmic-cervical insufficiency, except in cases of gross post-traumatic anatomical changes and some developmental anomalies, since currently existing tests are not fully informative and reliable.

Most authors consider a decrease in the length of the cervix to be the main diagnostic sign. During a vaginal examination in the speculum, this sign is characterized by flaccid edges of the external pharynx and gaping of the latter, and the internal pharynx freely allows the gynecologist’s finger to pass through.

The diagnosis before pregnancy is established if it is possible to insert dilator No. 6 into the cervical canal during the secretory phase. It is advisable to determine the state of the internal pharynx on the 18th – 20th day from the beginning of menstruation, that is, in the second phase of the cycle, using, in which the width of the internal pharynx is determined. Normally, its value is 2.6 mm, and the prognostically unfavorable sign is 6-8 mm.

During pregnancy itself, as a rule, women do not present any complaints, and clinical signs suggesting the possibility of a threat of miscarriage are usually absent.

In rare cases, such indirect symptoms ICN like:

• sensations of discomfort, “bloating” and pressure in the lower abdomen;
• stabbing pains in the vaginal area;
• discharge from the genital tract of a mucous or sanguineous nature.

During the period of observation in the antenatal clinic, a symptom such as prolapse (protrusion) of the amniotic sac is of considerable importance in relation to the diagnosis and management of a pregnant woman. At the same time, the degree of threat of termination of pregnancy is judged by 4 degrees of location of the latter:

• I degree - above the internal os.
• II degree - at the level of the internal pharynx, but is not visually determined.
• III degree - below the internal pharynx, that is, in the lumen of the cervical canal, which indicates a late detection of its pathological condition.
• IV degree - in the vagina.

Thus, the preliminary criteria clinical diagnostics isthmic-cervical insufficiency and inclusion of patients in risk groups are:

1. Anamnesis data on the presence in the past of low-painful miscarriages in late gestation or rapid premature births.
2. . It is taken into account that each subsequent pregnancy ended in premature birth at increasingly earlier gestational stages.
3. Pregnancy after long period infertility and use.
4. The presence of prolapse of the membranes in the cervical canal at the end of the previous pregnancy, which is established according to the anamnesis or from the dispensary registration card located in the antenatal clinic.
5. Data from vaginal examination and speculum examination, during which signs of softening of the vaginal cervix and its shortening, as well as prolapse of the amniotic sac in the vagina are determined.

However, in most cases, even a pronounced degree of prolapse of the amniotic sac occurs without clinical signs, especially in primigravidas, due to a closed external os, and risk factors cannot be identified until labor occurs.

In this regard, ultrasound for isthmic-cervical insufficiency with determination of the length of the cervix and the width of its internal pharynx (cervicometry) becomes highly diagnostic value. A more reliable method is an echographic examination using a transvaginal sensor.

How often should cervicometry be done for ICI?

It is carried out at the usual screening periods of pregnancy, corresponding to 10-14, 20-24 and 32-34 weeks. In women with recurrent miscarriage in the second trimester, in cases of obvious presence of an organic factor or if there is a suspicion of the possibility of post-traumatic changes from 12 to 22 weeks of pregnancy, it is recommended to conduct a dynamic study - every week or once every two weeks (depending on the results of examining the cervix in the mirrors ). If the presence of a functional factor is assumed, cervicometry is performed from 16 weeks of gestation.

The criteria for assessing echographic examination data, primarily on the basis of which the final diagnosis is made and treatment of ICI during pregnancy is selected, are:

1. In first- and multi-pregnant women with a period of less than 20 weeks, the length of the cervix, which is 3 cm, is critical in terms of threatening spontaneous abortion. Such women need intensive monitoring and inclusion in the risk group.
2. Up to 28 weeks during multiple pregnancy, the lower limit of normal cervical length is 3.7 cm for primigravidas, and 4.5 cm for multigravidas.
3. The normal cervical length in multiparous healthy pregnant women and women with ICI at 13-14 weeks is from 3.6 to 3.7 cm, and at 17-20 weeks the cervix with insufficiency is shortened to 2.9 cm.
4. An absolute sign of miscarriage, which already requires appropriate surgical correction for ICI, is a cervical length of 2 cm.
5. The normal width of the internal os, which is 2.58 cm by the 10th week, increases uniformly and reaches 4.02 cm by the 36th week. A decrease in the ratio of the length of the neck to its diameter in the area of ​​the internal os to 1.12 has a prognostic value. -1.2. Normally, this parameter is 1.53-1.56.

At the same time, the variability of all these parameters is influenced by the tone of the uterus and its contractile activity, low placental attachment and the degree of intrauterine pressure, which creates certain difficulties in interpreting the results in terms of differential diagnosis reasons for the threat of miscarriage.

Ways to maintain and prolong pregnancy

When choosing methods and drugs for correcting pathology in pregnant women, a differentiated approach is necessary.

These methods are:

• conservative - clinical guidelines, treatment with drugs, use of a pessary;
• surgical methods;
• their combination.

Includes psychological impact by explaining the possibility of successful pregnancy and childbirth, and the importance of following all the recommendations of the gynecologist. Advice is given regarding exclusion psychological stress, degrees physical activity depending on the severity of the pathology, the possibility of decompression exercises. Carrying loads weighing more than 1 - 2 kg, long walking, etc. are not allowed.

Is it possible to sit with ICN?

Prolonged stay in a sitting position, as well as a vertical position in general, contributes to an increase in intra-abdominal and intrauterine pressure. In this regard, during the day it is advisable to be in the horizontal position.

How to lie down correctly during ICN?

You need to rest on your back. The foot end of the bed should be raised. In many cases, strict bed rest is recommended, mainly observing the above position. All these measures can reduce the degree of intrauterine pressure and the risk of prolapse of the amniotic sac.

Drug therapy

Treatment begins with a course of anti-inflammatory and antibacterial therapy with drugs from the third generation fluoroquinolone or cephalosporin group, taking into account the results of preliminary bacteriological research.

To reduce and, accordingly, intrauterine pressure, antispasmodic drugs such as Papaverine orally or in suppositories, No-spa orally, intramuscularly or intravenously are prescribed. If they are insufficiently effective, tocolytic therapy is used, which contributes to a significant decrease in uterine contractility. The optimal tocolytic is Nifedipine, which has the lowest number side effects and their insignificant expression.

In addition, for ICN, it is recommended to strengthen the cervix with Utrozhestan organic origin up to 34 weeks of pregnancy, and in the functional form through the drug Proginova up to 5-6 weeks, after which Utrozhestan is prescribed up to 34 weeks. Instead of Utrozhestan, the active component of which is progesterone, analogues of the latter (Duphaston, or dydrogesterone) can be prescribed. In cases of hyperandrogenism, the basic drugs in the treatment program are glucocorticoids (Metypred).

Surgical and conservative methods for correcting ICI

Can the cervix lengthen with ICI?

In order to increase its length and reduce the diameter of the internal pharynx, methods such as surgical (suturing) and conservative in the form of installing perforated silicone obstetric pessaries are also used. various designs, contributing to the displacement of the cervix towards the sacrum and maintaining it in this position. However, in most cases, the cervix does not lengthen to the required (physiological for a given period) value. Usage surgical method and pessary is carried out against the background of hormonal and, if necessary, antibacterial therapy.

What is better - sutures or a pessary for ICI?

The procedure for installing a pessary, unlike surgical technique suturing, is relatively simple in terms of technical implementation, does not require the use of anesthesia, is easily tolerated by a woman and, most importantly, does not cause circulatory problems in the tissues. Its function is to reduce the pressure of the fertilized egg on the incompetent cervix, preserve the mucus plug and reduce the risk of infection.

Obstetric relief pessary

However, the use of any technique requires a differentiated approach. At organic form ICN application of circular or U-shaped (better) sutures is advisable during 14-22 weeks of pregnancy. If a woman has a functional form of pathology, an obstetric pessary can be installed within a period of 14 to 34 weeks. If the shortening of the cervix progresses to 2.5 cm (or less) or the diameter of the internal os increases to 8 mm (or more), surgical sutures are applied in addition to the pessary. Removal of the pessary and removal of sutures for PCN is carried out in a hospital setting at the 37th – 38th weeks of pregnancy.

Thus, the ICN is one of the most common reasons termination of pregnancy before 33 weeks. This problem has been sufficiently studied and adequately corrected ICI in 87% or more allows achieving the desired results. At the same time, correction methods, methods for monitoring their effectiveness, as well as the question of the optimal timing of surgical treatment still remain controversial.

They call a pathology, during the development of which there is a shortening and softening of the cervix, accompanied by its opening. In women carrying a child, the disease can cause spontaneous abortion.

IN natural state The uterine cervix is ​​like a muscular ring that can hold the fetus in the uterine cavity until the period established by nature. The load that occurs when conceiving a child increases as it develops, since due to the increasing volume of amniotic fluid, intrauterine pressure also increases.

As a result, when ICN forms, the cervix is ​​not able to cope with the load.

The symptoms of ICI are not very obvious, since there is no bleeding or pain when the cervix opens; profuse leucorrhoea, frequent urination and a feeling of heaviness in the lower abdomen may occur.

Indications and contraindications for the use of pessaries

With the development of ICI, specialist recommendations, in addition to complete rest, include surgical intervention or the use of special rings placed on the cervix and protecting it from dilatation. Such devices, made of plastic and silicone, are called pessaries.

There are a number of indications and contraindications for the use of obstetric pessaries. First, let's look at the ICN and clinical recommendations for the use of pessaries:

• the main indication is the presence of isthmic-cervical insufficiency in a patient with partial or complete opening of the cervix;
• miscarriages, premature labor accompanying previous pregnancies;
• ovarian dysfunction or genital infantilism;
• the ring can be installed as additional insurance if a previous pregnancy has ended caesarean section, in case of multiple pregnancy, in the presence of significant physical exertion or severe psycho-emotional state when conception occurred after long-term infertility treatment.

Despite the undoubted benefits that the use of pessaries brings, the method has certain contraindications. This may be individual intolerance to the device or noticeable discomfort when wearing the ring for a long time, fetal pathology and, accordingly, the need for abortion, narrowness of the vaginal opening or the presence of colpitis, which can contribute to the displacement of the pessary, bloody issues. In these cases, suturing of the uterine cervix may be used to preserve the fetus.

Features of using an obstetric ring

According to statistics, the risk of spontaneous abortion when installing a ring and premature labor is reduced by 85%. At the same time, there is certain prevention ICN during pregnancy and recommendations for installing the device:

• before installing a pessary, a woman must treat existing pathologies;
• the process itself can cause short-term painful sensations;
• to reduce discomfort, you will need to lubricate the ring with special creams or gels;
• pessaries are made different sizes and forms, their correct selection is the key to competent and accurate installation and high speed of patient adaptation to the device;
• the ring may put slight pressure on the bladder, a woman often needs several days to get used to it;
• when the pessary is installed low due to physiological characteristics female body The patient may urinate more frequently.

When removing the pessary there is no discomfort, the process is much easier than installation. After its elimination, the birth canal will need to be sanitized within seven days. Removing the ring does not cause premature labor.

Behavior when wearing a pessary and preventive measures

Typically, the behavior of a patient with an obstetric ring installed is no different from the lifestyle of other pregnant women, however, there are a number of recommendations that should not be neglected:

• when diagnosing ICI and installing an obstetric ring, sexual contact and overexcitation, which contributes to an increase in uterine tone, are prohibited;
• wearing a pessary does not require special hygiene care, however, you will need to take a smear regularly at intervals of two or three weeks. Depending on the results, irrigation or the use of suppositories may be prescribed;
• it is necessary to control the position of the ring and monitor the condition of the uterine cervix;
• The pessary should be worn for almost the entire remaining time until delivery after its installation. Typically, the ring is removed at 36-38 weeks;
• early removal of the ring is possible as the inflammatory processes, if it is necessary to provoke premature resolution of the burden in the presence of certain medical indicators.

Moreover, even with timely installation of the device, it is impossible to guarantee the continuation of pregnancy until a late term - labor can begin even with the presence of an obstetric ring. There are no complications after removal of the pessary.

As for the prevention of ICI, if it is present during pregnancy, the next conception should begin no earlier than two years later. After this, you will need to visit a gynecologist as soon as possible and register, following the recommendations of the leading specialist.

Even the presence of isthmic-cervical insufficiency, with timely consultation with a specialist, will provide all the necessary conditions for the child’s growth, development and birth.

When diagnosing ICN, you should not despair; in order to carry the child to the calculated term and ensure his natural birth, you will need:

• choose the right pregnancy management tactics;
• develop a therapeutic and protective regime;
• create the right psychological mood in a woman.

This approach will allow the baby to be born on time and ensure good health.

Our obstetric pessaries during pregnancy are an effective measure for the prevention and treatment of ICI. The products passed all the necessary requirements clinical trials and have all the necessary certificates and permits.

– a disorder associated with the opening of the cervix during embryogenesis, which leads to spontaneous abortion or premature delivery. Clinically this pathology Usually it does not manifest itself in any way, sometimes minor pain and a feeling of fullness, and the release of mucus and blood may appear. Ultrasound scanning is used to determine pathological changes and confirm the diagnosis. Health care consists of installing a Meyer ring (special pessary) in the vagina or surgical suturing. Drug therapy is also indicated.

General information

Isthmic-cervical insufficiency (ICI) is a pregnancy pathology that develops as a result of weakening of the muscle ring located in the area of ​​the internal os and unable to hold the fetus and its membranes. In obstetrics, this condition occurs in every tenth patient, usually occurs in the second trimester, and is less commonly diagnosed after 28 weeks of pregnancy. The danger of isthmic-cervical insufficiency lies in the absence of early symptoms, despite the fact that this pathological condition can lead to fetal death in the later stages or the onset of premature birth. If a woman experiences recurrent miscarriage, in about a quarter of clinical cases the cause of this condition is ICI.

With isthmic-cervical insufficiency, there is a decrease muscle tone from the area of ​​the internal pharynx, which leads to its gradual opening. As a result, part of the membranes descends into the lumen of the cervix. At this stage, isthmic-cervical insufficiency poses a real threat to the child, since even a slight load or active movements can cause a violation of the integrity of the amniotic sac, subsequent premature birth or fetal death. In addition, with ICI, infection can be transmitted to the fetus, since a certain microflora is always present in the genital tract.

Causes of isthmic-cervical insufficiency

The etiology of isthmic-cervical insufficiency is a decrease in the tone of the muscle fibers that form the uterine sphincter. Its main role is to maintain the cervix closed until labor occurs. With isthmic-cervical insufficiency, this mechanism is disrupted, which leads to premature opening of the cervical canal. Often the cause of ICI is a history of traumatic injuries to the cervix. The likelihood of developing isthmic-cervical insufficiency increases in women who have suffered late abortions, ruptures, or surgical births (application of obstetric forceps).

Isthmic-cervical insufficiency often occurs after fetal destruction operations, breech birth and surgical interventions on the cervix. All these factors cause trauma to the cervix and possible violation the location of muscle fibers relative to each other, which ultimately contributes to their failure. Also, the cause of isthmic-cervical insufficiency can be congenital anomalies associated with abnormal structure of the organs of the reproductive system of a pregnant woman. Congenital ICI is quite rare, and can be determined even in the absence of conception - in such a case, at the time of ovulation, the cervical canal will dilate by more than 0.8 cm.

Isthmic-cervical insufficiency is often observed against the background of hyperandrogenism - an increased content of male sex hormones in the patient’s blood. An increase in the likelihood of developing pathology is observed when this problem is combined with a deficiency of progesterone production. An aggravating factor for isthmic-cervical insufficiency is multiple births. Along with increased pressure on the cervix, in such cases an increase in the production of the hormone relaxin is often detected. For the same reason, isthmic-cervical insufficiency is sometimes diagnosed in patients who have undergone ovulation induction with gonadotropins. The likelihood of developing this pathology increases in the presence of a large fetus, polyhydramnios, and the presence of bad habits, performing heavy physical work during the gestation period.

Classification of isthmic-cervical insufficiency

Taking into account the etiology, two types of isthmic-cervical insufficiency can be distinguished:

• Traumatic. Diagnosed in patients with a history of operations and invasive manipulations on the cervical canal, resulting in scar formation. The latter consists of connective tissue elements that cannot withstand increased load due to fetal pressure on the cervix. For the same reason, traumatic isthmic-cervical insufficiency is possible in women with a history of ruptures. ICI of this type manifests itself mainly in the 2-3 trimester, when the weight of the pregnant uterus rapidly increases.
• Functional. Typically, such isthmic-cervical insufficiency is provoked by a hormonal disorder, caused by hyperandrogenism or insufficient production of progesterone. This form often occurs after the 11th week of embryogenesis, which is due to the beginning of the functioning of the endocrine glands in the fetus. The endocrine organs of the child produce androgens, which, together with substances synthesized in the woman’s body, lead to a weakening of muscle tone and premature opening of the cervical canal.

Symptoms of isthmic-cervical insufficiency

Clinically, isthmic-cervical insufficiency, as a rule, does not manifest itself in any way. If symptoms are present, the signs of pathology depend on the period at which the changes occurred. In the first trimester, isthmic-cervical insufficiency may be indicated by bleeding, not accompanied by pain, in rare cases combined with minor discomfort. On later stages(after 18-20 weeks of embryogenesis) ICI leads to fetal death and, accordingly, miscarriage. Bleeding occurs and discomfort in the lower back and abdomen is possible.

The peculiarity of isthmic-cervical insufficiency is that even with a timely visit to an obstetrician-gynecologist, due to the lack of obvious symptoms, it is not easy to identify pathological changes. This is due to the fact that routinely during each consultation an objective gynecological examination is not carried out to reduce the likelihood of introduction pathogenic microflora. However, even during a gynecological examination, it is not always possible to suspect manifestations of isthmic-cervical insufficiency. The reason for holding instrumental diagnostics may cause excessive softening or reduction in the length of the neck. It is these symptoms that often indicate the onset of isthmic-cervical insufficiency.

Diagnosis of isthmic-cervical insufficiency

Ultrasound scanning is the most informative method in identifying isthmic-cervical insufficiency. A sign of pathology is shortening of the cervix. Normally, this indicator varies and depends on the stage of embryogenesis: before 6 months of pregnancy it is 3.5-4.5 cm, in later stages - 3-3.5 cm. With isthmic-cervical insufficiency, these parameters change to a lesser extent. The threat of interruption or premature birth of the baby is indicated by a shortening of the canal to 25 mm.

V-shaped neck opening – characteristic feature isthmic-cervical insufficiency, which is observed in both parous and nulliparous patients. This symptom can be detected by ultrasound monitoring. Sometimes, to confirm the diagnosis during scanning, a test with increasing load is performed - the patient is asked to cough or lightly presses on the bottom of the uterine cavity. In women who have given birth, isthmic-cervical insufficiency is sometimes accompanied by an increase in the lumen of the cervix along its entire length. If a woman is at risk or has indirect signs of ICI, monitoring should be carried out twice a month.

Treatment of isthmic-cervical insufficiency

In case of isthmic-cervical insufficiency, complete rest is indicated. It is important to protect a pregnant woman from negative factors: stress, harmful working conditions, intense physical activity. The question of the conditions for subsequent pregnancy management is decided by the obstetrician-gynecologist, taking into account the patient’s condition and the severity of pathological changes. Conservative care for isthmic-cervical insufficiency involves installing a Meyer ring in the vagina, which reduces fetal pressure on the cervix. The procedure is recommended to be carried out during the embryogenesis period of 28 weeks or more with a slight opening of the pharynx.

Surgical intervention for isthmic-cervical insufficiency makes it possible to carry the baby to term with a high probability. The manipulation involves placing a suture on the neck to prevent its premature opening. The operation is performed under anesthesia; to perform it you need following conditions: signs of the integrity of the membranes and the vital activity of the fetus, gestational age up to 28 weeks, absence of pathological discharge and infectious processes from the genitals. Sutures and pessaries for isthmic-cervical insufficiency are removed upon reaching the embryogenesis period of 37 weeks, as well as in the event of labor, opening of the amniotic sac, formation of a fistula, or bleeding.

During conservative therapy and in the postoperative period, patients with isthmic-cervical insufficiency are prescribed antibacterial drugs to prevent the development of infection. The use of antispasmodics is also indicated, and tocolytics for hypertonicity of the uterus. In the functional form of isthmic-cervical insufficiency, hormonal agents can be additionally used. Delivery is possible through the vaginal genital tract.

Forecast and prevention of isthmic-cervical insufficiency

With isthmic-cervical insufficiency, a woman can carry the baby to the expected date of birth. Due to a weak muscle sphincter, the risk of precipitate labor increases, if there is a possibility of developing this state Pregnant women are hospitalized in the obstetric department. Prevention of isthmic-cervical insufficiency involves timely examination and treatment of identified diseases (especially hormonal ones) even at the stage of planning conception. After fertilization, the patient must normalize her work and rest schedule. It is important to exclude stress factors and hard work. Specialists should closely monitor the woman’s condition and determine as early as possible whether she is at risk for developing ICI.

One of the most common causes of early termination of pregnancy in the second and third trimesters is ICI (incompetence of the cervix). ICI is an asymptomatic shortening of the cervix, expansion of the internal os, leading to rupture of the membranes and loss of pregnancy.

CLASSIFICATION OF ISTHMICO-CERVICAL INSUFFICIENCY

· Congenital ICI (with genital infantilism, uterine malformations).
· Purchased ICN.
- Organic (secondary, post-traumatic) ICI occurs as a result of therapeutic and diagnostic manipulations on the cervix, as well as traumatic childbirth, accompanied by deep ruptures of the cervix.
- Functional ICI is observed in endocrine disorders (hyperandrogenism, ovarian hypofunction).

DIAGNOSIS OF ISTHMICO-CERVICAL INSUFFICIENCY

Criteria for diagnosing ICI during pregnancy:
· Anamnestic data (history of spontaneous miscarriages and premature births).
· Vaginal examination data (location, length, consistency of the cervix, condition of the cervical canal - patency of the cervical canal and internal os, scar deformity cervix).

The severity of ICI is determined using the Stember point scale (Table 141).

A score of 5 or more requires correction.

Ultrasound (transvaginal echography) is of great importance in the diagnosis of ICI: the length of the cervix, the condition of the internal pharynx and the cervical canal are assessed.

Table 14-1. Score assessment of the degree of isthmic-cervical insufficiency according to the Stember scale

Ultrasound monitoring of the cervix should be performed starting in the first trimester of pregnancy to truly assess the reduction in cervical length. A cervical length of 30 mm is critical at less than 20 weeks and requires intensive ultrasound monitoring.

Ultrasound signs of ICN:

· Shortening of the cervix to 25–20 mm or less, or opening of the internal os or cervical canal to 9 mm or more. In patients with an opening of the internal pharynx, it is advisable to evaluate its shape (Y, V or U-shaped), as well as the severity of the depression.

INDICATIONS FOR SURGICAL CORRECTION OF ISTHMYCOCERVICAL INSUFFICIENCY

· A history of spontaneous miscarriages and premature births.
· Progressive ICI according to clinical and functional research methods:
- signs of ICI according to vaginal examination;
- ECHO signs of ICI according to transvaginal sonography.

CONTRAINDICATIONS TO SURGICAL CORRECTION OF ISTHMYCOCERVICAL INSUFFICIENCY

· Diseases and pathological conditions that are a contraindication to prolongation of pregnancy.
· Bleeding during pregnancy.
· Increased tone uterus, not amenable to treatment.
· Congenital malformation of the fetus.
· Acute inflammatory diseases pelvic organs (PID) - III–IV degree of purity of vaginal contents.

CONDITIONS FOR THE OPERATION

· Gestation period 14–25 weeks ( optimal time gestation for cervical cerclage - up to 20 weeks).
· Whole amniotic sac.
· Lack of significant cervical effacement.
· Absence of pronounced prolapse of the membranes.
· No signs of chorioamnionitis.
· Absence of vulvovaginitis.

PREPARATION FOR OPERATION

· Microbiological examination of vaginal discharge and cervical canal.
· Tocolytic therapy as indicated.

METHODS OF PAIN RELIEF

· Premedication: atropine sulfate at a dose of 0.3–0.6 mg and midozolam (dormicum©) at a dose of 2.5 mg intramuscularly.
· Ketamine 1–3 mg/kg body weight intravenously or 4–8 mg/kg body weight intramuscularly.
Propofol 40 mg every 10 s intravenously until clinical symptoms anesthesia. The average dose is 1.5–2.5 mg/kg body weight.

SURGICAL METHODS FOR CORRECTION OF ISTHMICO-CERVICAL INSUFFICIENCY

The most acceptable method currently is:

· Method of suturing the cervix with a circular purse-string suture according to MacDonald.
Surgery technique: At the border of the transition of the mucous membrane of the anterior vaginal vault, a purse-string suture made of durable material (lavsan, silk, chrome-plated catgut, mersilene tape) is applied to the cervix with a needle passed deep through the tissue, the ends of the threads are tied with a knot in the anterior vaginal vault. The long ends of the ligature are left so that they are easy to detect before delivery and can be easily removed.

It is also possible to use other methods for correcting ICN:

· Shaped sutures on the cervix according to the method of A.I. Lyubimova and N.M. Mamedalieva.
Operation technique:
At the border of the transition of the mucous membrane of the anterior vaginal vault, 0.5 cm away from the midline on the right, the cervix is ​​pierced with a needle with Mylar thread through the entire thickness, making a puncture in the posterior part of the vaginal vault.
The end of the thread is transferred to the left lateral part of the vaginal vault, the mucous membrane and part of the thickness of the cervix are pierced with a needle, making an injection 0.5 cm to the left of the midline. The end of the second Mylar thread is transferred to the right lateral part of the vaginal vault, then the mucous membrane and part of the thickness of the uterus are pierced with a puncture in the anterior part of the vaginal vault. Leave the tampon in for 2–3 hours.

· Suturing the cervix using the method of V.M. Sidelnikova (for severe ruptures of the cervix on one or both sides).
Operation technique:
The first purse string suture is placed using the MacDonald method, just above the cervical rupture. The second purse-string suture is carried out as follows: below the first, 1.5 cm, a thread is passed through the thickness of the wall of the cervix from one edge of the rupture to the other in a circular manner along a spherical circle. One end of the thread is stuck inside the cervix into the back lip and, picking up the side wall of the cervix, the puncture is made in the front part of the vaginal vault, twisting the torn lateral anterior lip of the cervix like a snail, and brought out into the front part of the vaginal vault. Threads bind.
For suturing, modern suture material “Cerviset” is used.

COMPLICATIONS

· Spontaneous termination of pregnancy.
· Bleeding.
· Rupture of the amniotic membranes.
· Necrosis, cutting through the cervical tissue with threads (lavsan, silk, nylon).
· Formation of bedsores, fistulas.
· Chorioamnionitis, sepsis.
· Circular rupture of the cervix (at the onset of labor and the presence of sutures).

FEATURES OF MANAGEMENT IN THE POSTOPERATIVE PERIOD

· You are allowed to stand up and walk immediately after the operation.
· Treatment of the vagina and cervix with a 3% solution of hydrogen peroxide, benzyldimechloride monohydrate, chlorhexidine (in the first 3–5 days).
· The following medications are prescribed for therapeutic and prophylactic purposes.
- Antispasmodics: drotaverine 0.04 mg 3 times a day or intramuscularly 1–2 times a day for 3 days.
- b Adrenomimetics: hexoprenaline at a dose of 2.5 mg or 1.25 mg 4 times a day for 10–12 days, at the same time verapamil is prescribed at a dose of 0.04 g 3–4 times a day.
- Antibacterial therapy according to indications at high risk infectious complications taking into account data microbiological research vaginal discharge with sensitivity to antibiotics.
· Discharge from the hospital is carried out on the 5th–7th day (in case of uncomplicated course postoperative period).
· IN outpatient setting The cervix is ​​examined every 2 weeks.
· Sutures from the cervix are removed at 37–38 weeks of pregnancy.

INFORMATION FOR THE PATIENT

· If there is a threat of miscarriage, especially with recurrent miscarriage, it is necessary to monitor the condition of the cervix using ultrasound.
· The effectiveness of surgical treatment of ICI and pregnancy rate is 85–95%.
· It is necessary to observe a medical regime.