Preterm pregnancy. Unintention of pregnancy. Isthmiko-cervical insufficiency

Unintention of pregnancy - one of the most frequent complications of the gestational process and its frequency from 15 to 20% of all desired pregnancies, including 5-10% are 3-3r381. preterm labor . The threat of interruption complicates the course of pregnancy in almost 40% of women. Among the stillborn children, premature newborns make up more than 50%, and among the dead in the early neonatal period - 70-80%. The indicator of perinatal mortality, with miscarriage, is 30-40 times higher than that with timely delivery.

The concept of miscarriage combines the cases of unauthorized interruption at the term of up to 37 weeks and consists of the concepts of early spontaneous abortion (up to 12 weeks) of late spontaneous abortion (13 to 28 weeks) premature delivery (from 29 to 37 weeks). Miscarriage did not occur, call pregnancy in cases of intrauterine fetal death until 28 weeks of pregnancy; births that did not take place - delivery after the 29th week of pregnancy. The presence of two or more cases of miscarriage in a history is the basis for establishing the diagnosis: "The habitual miscarriage of ".

The concept of miscarriage and premature births in essence have changed, and especially this concerns the concept of "premature baby." So, since 1948 (the decision of the World Assembly under the League of Nations) until recently, preterm infants considered babies born after 28 weeks of pregnancy with a body weight of 1000g to 2500g and a height of 35cm to 46cm, and premature births - 28 to 37 weeks. Since 1972 (according to WHO recommendations), all babies born from 22 to 38 weeks of gestation are considered premature, regardless of their weight.

Reasons for miscarriage

The reasons for miscarriage are different. According to Sedelnikov, VM. (1986), the following are distinguished: the presence of genital and extragenital infection, toxoplasmosis, endocrine diseases, sexual infantilism, complications during pregnancy (toxicoses, hydramnios), extragenital diseases, malformations of the uterus and fetus, uterine tumors, immunological incompatibility of the mother and fetus according to the Rh-factor or blood group, ischemic-cervical insufficiency (cervix gradually opens and does not retain the fetus in the uterine cavity), genetic pathology of the mother and fetus, socio-biological factors (age, number of births and sides of the woman, family composition, nature of work, bad habits, food, etc.).

The pathogenesis of miscarriage is often multifactorial. The reason why pregnancy is interrupted in the first trimester can be determined in about 40% of women, in II - in 30%. In this regard, most of the proposed etiopathogenetic classifications are inadequate. Early spontaneous abortions are mainly caused by genetic defects in the fertilization product, by immunological or endocrine causes that disrupt the physiology of implantation and placentation, while late miscarriages and premature births are mainly due to common maternal causes (infections, metabolic diseases, ischemicocervical insufficiency, trauma, complications of pregnancy, etc.).

Isthmiko-cervical insufficiency

Isthmiko-cervical insufficiency Is a pathology that arises from the inadequacy of the blocking function of the cervix. Insufficiency of the cervix arises as a result of structural and functional changes in the isthmic part of the uterus and can be organic and functional.

Most often, the cause of organic istmiko-cervical insufficiency is the preceding pregnancy, scraping of the uterus cavity, accompanied by mechanical dilatation of the cervix, and rupture of the cervix after pathological birth.

The pathogenesis of functional isthmico-cervical insufficiency is complex and insufficiently studied . Sometimes congenital isthmicocervical insufficiency is found in women with uterine hypoplasia in genital infantilism and in women with developmental defects of the uterus. The mechanism of interruption of pregnancy in istrmico-cervical insufficiency is associated with the reduction and softening of the cervix, the opening of the internal pharynx and cervix of the uterus, as a result of which the fetal egg has no physiological resistance in the lower segment of the uterus. With the progression of pregnancy, the membranes of the vipyachuyutsya in the dilated canal of the cervix, become infected, torn and abortion occurs.

Depending on the manifestation of symptoms in the clinical course of spontaneous abortion, there are isolated: threats of spontaneous miscarriage, miscarriage, started, miscarriage, full and incomplete abortion.

At threat of a miscarriage (abortus imminens) a feeling of heaviness or is noted. slight pulling pain in the lower abdomen, in the field of the sacrum. With abortion in the second trimester, pain can be of the nature of contractions. Blood discharge is almost absent or insignificant in the form of blood veins in the mucous contents of the cervical canal. The cervix is ​​formed, located eccentrically, the external yoke is closed, the tone of the uterus is elevated. The size of the uterus corresponds to the period of pregnancy. Conducting preserving therapy makes it possible to prolong pregnancy.

With a miscarriage, which began (abortus incipiens), cramping pain more expressive than with a threatening miscarriage. Appear spotting. The fetal egg exfoliates partially, so the size of the uterus remains appropriate for the gestation period. The cervix is ​​formed, the cervical canal is either closed, or somewhat open. With ischemic-cervical insufficiency, there is no pain, the cervical canal is somewhat open, the neck is softened, centered, shortened. When the appropriate therapy is carried out, the pregnancy can be saved.

Abortion in the course (abortus progrediens) is accompanied by cramping pains in the lower abdomen, significant bleeding from the genital tract. The cervix is ​​centered, shortened, its open channel, the elements of the fetal egg are in the neck and can be defined in the vagina. Preservation therapy is not carried out.

With incomplete abortion (abortus incompletus), the fetal egg is partially outside the uterine cavity, characterized by significant cramping pains in the lower abdomen and varying intensity of bleeding from the vagina. The cervix is ​​open, the uterus is soft, its size is determined less than those that correspond to the term of pregnancy. Elements of the fetal egg in the form of membranes and pieces of the chorion (placenta) are retained in the uterine cavity.

Complete abortion (abortus completus), which is more common in later terms, is characterized by complete isolation of the fetal egg from the uterine cavity. The uterus contracts, it becomes less than it should be in the appropriate gestational age, the bleeding stops.

With an abortion that did not take place (missed abortion), the fetal egg remains in the uterus after its death and undergoes secondary changes, the amniotic fluid is gradually absorbed. The woman ceases to feel pregnant, the size of the uterus is less for the corresponding period of pregnancy. Instrumental emptying of the uterine cavity is carried out.

Premature birth is considered expedient to distribute to menacing, such that begin and have begun.

Threatening preterm labor characterized by pain in the lower back and lower abdomen. Excitability and tone of the uterus are increased. With a vaginal examination, a centered, formed cervix is ​​found, the outer cervix is ​​closed.

With premature births that have begun, there are cramping pains in the lower abdomen or regular contractions. With vaginal examination, we find changes in the cervix (contractions, smoothing, opening at 2-4 cm). Premature birth in 40% of cases begins with premature rupture of membranes. Generic activity is more often pathological in nature. With ischemic-cervical insufficiency such births are rapid. At that time, the duration of such births may increase due to the unpreparedness of the cervix with premature rupture of the membranes in the third trimester of pregnancy accompanied by ascending infection of the fetus, the development of chorionamnionitis and septic complications in the postpartum period. Premature birth is sometimes associated with bleeding, which occurs due to premature detachment of the normally located placenta.

Premature birth began, characterized by regular labor, which resulted in significant structural changes in the cervix (its softening, smoothing, opening more than 4-5 cm). As a rule, in all cases, premature birth is accompanied by fetal hypoxia.