Cervical insufficiency is a disorder associated with the opening of the cervix during embryogenesis, which leads to spontaneous abortion or premature delivery. Clinically, this pathology usually does not manifest itself in any way, sometimes there may be minor pain and a feeling of bursting, the release of mucus with blood. Ultrasound scanning is used to determine pathological changes and confirm the diagnosis. Medical care consists in the installation of a Meyer ring (a special pessary) in the vagina or surgical suturing. Drug therapy is also indicated.
Cervical insufficiency (CI) is a pathology of pregnancy that develops due to the weakening of the muscle ring located in the zone of the inner pharynx and unable to hold the fetus and its membranes. In obstetrics, this condition occurs in every tenth patient, usually occurs in the second trimester, less often diagnosed after 28 weeks of pregnancy. The danger lies in the absence of early symptoms, despite the fact that this pathological condition can lead to stillbirth at a later date or the onset of premature birth. If a woman has a habitual miscarriage of pregnancy, in about a quarter of clinical cases, the cause of this condition is the CI.
There is a decrease in muscle tone from the area of the inner pharynx, which leads to its gradual opening. As a result, part of the fetal membranes descends into the lumen of the cervix. At this stage, 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 fetal bladder, subsequent premature birth or fetal death. In addition, with CI, it is possible to introduce infection to the fetus, since there is always a certain microflora in the genital tract.
The etiology of 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 in a closed state until the onset of labor. With cervical insufficiency, this mechanism is disrupted, which leads to premature opening of the cervical canal. Often, the cause of CI is traumatic injuries of the cervix in the anamnesis. The probability of developing this disease increases in women who have undergone late abortions, ruptures, operative childbirth (the imposition of obstetric forceps).
Cervical insufficiency often occurs after fruit-destroying operations, childbirth in the pelvic presentation and surgical interventions on the cervix. All these factors cause injury to the cervix and a possible violation of the location of muscle fibers relative to each other, which ultimately contributes to their insolvency. Also, the cause may be congenital anomalies associated with the incorrect structure of the organs of the reproductive system of a pregnant woman. Congenital CI is quite rare, which can be determined even in the absence of conception – in such a case, at the time of ovulation, the opening of the cervical canal by more than 0.8 cm will be noted.
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 noted when this problem is combined with a deficiency of progesterone production. The aggravating factor is multiple pregnancy. 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, cervical insufficiency is sometimes diagnosed in patients who have undergone ovulation induction with gonadotropins. The probability of developing this pathology increases in the presence of a large fetus, polyhydramnios, the presence of bad habits in the patient, performing heavy physical work during gestation.
Taking into account the etiology , two types of cervical insufficiency can be distinguished:
- Traumatic. It is diagnosed in patients with a history of operations and invasive manipulations on the cervical canal, which resulted in the formation of a scar. The latter consists of connective tissue elements that cannot withstand increased load when the fetus presses on the cervix. For the same reason, traumatic cervical insufficiency is possible in women with a history of ruptures. The CI of this type manifests itself mainly in the 2-3 trimester, when the weight of the pregnant uterus increases rapidly.
- Functional. Usually, such cervical insufficiency is provoked by a hormonal disorder, caused by hyperandrogenism or insufficient progesterone production. 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, in combination with substances synthesized in the body of a woman, lead to a weakening of muscle tone and premature opening of the cervical canal.
Clinically, cervical insufficiency, as a rule, does not manifest itself in any way. In the presence of symptoms, the signs of pathology depend on the period at which the changes occurred. In the first trimester, anointing may be indicated, not accompanied by pain, in rare cases combined with minor discomfort. In the later stages (after 18-20 weeks of embryogenesis), the CI leads to fetal death and, accordingly, miscarriage. There is bleeding, possible discomfort in the lower back, abdomen.
The peculiarity of the disease is that even with a timely visit to an obstetrician-gynecologist, it is not easy to identify pathological changes due to the lack of obvious symptoms. This is due to the fact that an objective gynecological examination is not carried out routinely during each consultation in order to reduce the likelihood of pathogenic microflora. However, even during gynecological examination, it is not always possible to suspect manifestations. The reason for carrying out instrumental diagnostics may be excessive softening or reduction of the neck length. It is these symptoms that often indicate the onset of insufficiency.
Ultrasound scanning is the most informative method in detecting this pathology. A sign of pathology is shortening of the cervix. Normally, this indicator varies and depends on the stage of embryogenesis: up to 6 months of pregnancy, it is 3.5-4.5 cm, at later stages – 3-3.5 cm. With this disease, these parameters change in a smaller direction. The threat of interruption or premature birth of the baby is indicated by the shortening of the channel to 25 mm.
The V-shaped opening of the neck is a characteristic sign of pathology, which is observed both in women who gave birth and in patients who did not give birth. It is possible to detect such a symptom during ultrasound monitoring. Sometimes, to confirm the diagnosis during the scan, a test is performed with an increased load – the patient is asked to cough or put a little pressure on the bottom of the uterine cavity. In patients who gave birth, it is sometimes accompanied by an increase in the lumen of the cervix throughout. If a woman belongs to a risk group or has indirect signs of CI, monitoring should be carried out twice a month.
With cervical insufficiency, complete rest is indicated. It is important to protect a pregnant woman from negative factors: stress, harmful working conditions, intense physical exertion. The question of the conditions of subsequent pregnancy management is decided by an obstetrician-gynecologist, taking into account the patient’s condition and the severity of pathological changes. Conservative care involves the installation of a Meyer ring in the vagina, which reduces fetal pressure on the cervix. The procedure is recommended to be carried out during embryogenesis for 28 weeks or more with a slight opening of the pharynx.
Surgical intervention makes it possible to deliver the baby to the right time with a high probability. Manipulation involves the imposition of a seam on the neck, preventing its premature opening. The operation is performed under anesthesia, the following conditions are necessary for its implementation: signs of the integrity of the fetal membranes and the vital activity of the fetus, pregnancy up to 28 weeks, the absence of pathological secretions and infectious processes on the part of the genitals. Sutures and pessary are removed upon reaching the period of embryogenesis of 37 weeks, as well as in the case of childbirth, opening of the fetal bladder, formation of a fistula or the occurrence of bleeding.
During conservative therapy and in the postoperative period, patients are prescribed antibacterial drugs to prevent the development of infection. The use of antispasmodics is also shown, with uterine hypertension – tocolytics. With a functional form, hormonal agents can additionally be used. Delivery is possible through the natural genital tract.
Prognosis and prevention
A woman can deliver a baby before the expected date of birth. Due to a weak muscle sphincter, the risk of precipitous labor increases, if there is a possibility of developing this condition, pregnant women are hospitalized in the obstetric department. Prevention involves timely examination and treatment of detected diseases (especially hormonal ones) even at the stage of conception planning. After fertilization, the patient should normalize the work and rest regime. It is important to exclude stressful factors, hard work. Specialists should closely monitor the condition of a woman and determine as early as possible whether she is at risk for the development of CI.