Neck and perineal-neck pregnancy

Cervical and isthmic-cervical pregnancy is a relatively rare complication of pregnancy, which is a distal variant of ectopic pregnancy.

In a true cervical pregnancy, the fertilized egg develops only in the cervical canal. In a cervicothemmal pregnancy, the cervix and isthmus area are the receptacle for the fetus. Cervical and isthmic-cervical localization is observed in 0.3-0.4% of cases of all variants of ectopic (extrauterine) pregnancy. In relation to all pregnancies, cervical and isthmic-cervical pregnancies occur from 1:12,500 to 1:95,000.

Cervical-isthmic and cervical pregnancy pose a serious threat not only to the health but also to the life of the patient. The cause of death is most often bleeding (in 75-85% of cases), less often - infection.

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Causes of cervical and isthmic-cervical pregnancy

The occurrence of distal ectopic pregnancy is associated with the following causal factors: impossibility or difficult nidation of the fertilized egg in the body of the uterus, associated with the inferiority of the endometrium or with insufficient maturity of the trophoblast, in the presence of circumstances that favor the sliding of the blastocyst into the cervical canal. Such conditions occur in women who have had complicated previous births and the postpartum period, multiple abortions, surgical interventions on the uterus, uterine fibroids, isthmic-cervical insufficiency.

The trophoblast and then the chorionic villi implanted in the cervix and in the isthmus of the uterus of the fertilized egg penetrate the mucous membrane and penetrate the muscular layer. Melting of the muscular elements and vessels leads to bleeding and disruption of the development of pregnancy. In some cases, the wall of the cervix may be completely destroyed and the chorionic villi may penetrate into the parametrium or into the vagina.

Due to the absence of protective mechanisms inherent in the decidual membrane of the uterine body, the wall of the cervix is destroyed quite quickly by the developing fertilized egg. In a true cervical pregnancy, this process occurs within 8, rarely 12 weeks. In the case of isthmic-cervical localization, pregnancy can exist for a longer period: 16-20-24 weeks. Extremely rarely, a pathological distal ectopic pregnancy can be carried to term.

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Symptoms of cervical and isthmic-cervical pregnancy

Symptoms of cervical pregnancy are largely determined by the gestational age and the level of implantation of the fertilized egg. The main manifestation of the disease is bleeding from the genital tract against the background of a previous delay in the next menstruation in the absence of a pain symptom. Bleeding can be moderate, heavy or profuse. Many patients experience periodic scanty spotting of blood before the onset of bleeding. In some pregnant women, such discharge appears only in the early stages, and then the pregnancy proceeds for a more or less long time without pathological manifestations.

In a number of patients, cervical pregnancy first manifests itself during an artificial abortion.

Many authors believe that cervical pregnancy diagnostics presents certain difficulties. Late diagnostics of cervical pregnancy is largely explained by the rarity of the disease, so doctors forget about it. One can agree with this position, however, the degree of difficulties that a practicing physician encounters when diagnosing cervical pregnancy varies.

Diagnosis of cervical and isthmic-cervical pregnancy

It is quite easy to diagnose a true cervical pregnancy of 8-12 weeks if nidation of the fertilized egg occurred in the lower or middle part of the cervix. Typical cases involve pregnant women with a history of childbirth and abortions who are admitted to the hospital due to bleeding of varying severity. The general condition of the patient corresponds to the volume of blood loss. When examining with a mirror, an eccentric position of the external os is detected, and in some patients a network of dilated venous vessels is noticeable on the vaginal part of the cervix. During a bimanual examination, the cervix appears spherically enlarged, soft in consistency, and on it, in the form of a "cap", there is a small, denser body of the uterus, immediately behind the external os, the fertilized egg is palpated, tightly connected to the walls of the cervix; an attempt to separate it with a finger or instrument is accompanied by increased bleeding.

It is more difficult to diagnose a cervical pregnancy, in which the fetal receptacle bed is located in the upper part of the cervical canal. In such cases, patients may also notice scanty bleeding from the early stages of pregnancy. and then severe bleeding without pain occurs. Examination with mirrors does not reveal pathological changes in the cervix, which turns out to be cyanotic, as in a normal pregnancy, with a central location of the external os. During a bimanual examination, an experienced doctor may pay attention to the short vaginal part of the cervix, above which the fetal receptacle is located in the expanded upper part of the cervix with the adjacent denser body of the uterus. The data of a gynecological examination are therefore not indicative, therefore, in such situations, the correct diagnosis is most often established by curettage (sometimes repeated) of the uterus. When performing this operation, the doctor should pay attention to the following points:

1. dilation of the external os occurs very easily, but is accompanied by severe bleeding;
2. there is no sensation of the instrument passing through the internal os;
3. removal of the fertilized egg is difficult and does not stop the bleeding;
4. After emptying the ovary with a curette, you can feel a depression (“niche”) at the site of the former attachment of the ovum; the presence of a “niche” and thinning of the cervical wall can be confirmed by inserting a finger into the cervical canal.

Sometimes it is necessary to clarify the diagnosis after a curettage of the uterus performed by another doctor. In such cases, a dilated, flabby upper part of the cervix can be detected in the form of a sac. If it is possible to insert a finger into the cervical canal, then the detection of a niche and thinning of the cervical wall confirms the diagnosis.

Diagnosis of cervico-isthmic pregnancy presents significant difficulties, since typical symptoms associated with changes in the cervix (eccentric location of the external os, balloon-like dilation of the cervix with a slight increase in the body of the uterus) are usually absent in such cases. This complication of pregnancy can be suspected based on periodically recurring bleeding, which becomes more and more profuse with the increase in the pregnancy term. In the first trimester of pregnancy, the fact that repeated bleeding is not accompanied by pain (the body of the uterus is intact) and the fertilized egg is not expelled often attracts attention. However, doctors do not attach due importance to these features of the course of pregnancy, since profuse bleeding prompts a quick clarification of the pregnancy term and the beginning of emptying the uterus. Meanwhile, a careful gynecological examination may reveal a shortening of the vaginal portion of the cervix, a softened, widened upper portion of the cervix, merging with the denser body of the uterus, which does not correspond to the gestational age. When starting to remove the ovum and scrape the walls of the fetal receptacle, one should always remember that this manipulation can be of invaluable help in diagnosing both cervical and cervico-isthmic pregnancy. Difficulty in evacuating the ovum, ongoing and even increasing bleeding, detection of a crater-shaped depression in the wall of the fetal receptacle - these are the landmarks that help to recognize this pathology.

An isthmic-cervical pregnancy in the second trimester has no pathognomonic symptoms. The longer the pregnancy, the more often the clinical picture of an isthmic-cervical pregnancy resembles the clinical manifestations of placenta previa. The correct diagnosis is often established after the birth of the fetus. Retention of the placenta or its parts requires instrumental or (less often) digital entry into the uterus, during which an attentive physician discovers overstretching and thinning of the lower segment of the cervix and an intact body of the uterus.

In recent years, ultrasound examination has been of great help in timely diagnosis of cervical and isthmic-cervical pregnancy. Transverse and longitudinal scanning allows to determine the bulb-shaped expansion of the cervix, exceeding the size of the body of the uterus.

In some women, not only is the fertilized egg visualized in the dilated cervical canal, but the embryo's cardiac activity is also recorded.

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Treatment of cervical and isthmic-cervical pregnancy

Treatment of patients with cervical and isthmo-cervical pregnancy can currently only be surgical. The operation should be started immediately after the diagnosis is established. The slightest delay in the doctor's actions poses a threat of death of the patient from profuse bleeding.

The operation of choice is extirpation of the uterus, which should be performed in 3 stages:

1. laparotomy, ligation of vessels;
2. resuscitation measures;
3. hysterectomy.

Such interventions as suturing bleeding vessels of the cervix or conservative plastic surgery on the cervix with excision of the fetal receptacle bed cannot be recommended for widespread practice.