Factors of abortion

Among the factors of abortion, complications of pregnancy take a big place: gestations of the second half of pregnancy, anomalies of placenta attachment, premature detachment of the placenta, improper position of the fetus. Of the prenatal hemorrhages, the greatest importance is bleeding associated with placenta previa and abruption of the normally located placenta, as they are accompanied by high perinatal mortality and are dangerous for the life of a woman. The causes of placenta prevalence or attachment in the lower parts can not be considered fully studied.

In recent years, data have appeared that allow a new approach to solving the problem of preventing this dangerous obstetrical pathology.

In the general population, the prevalence of the placenta is 0.01-0.39%. According to research, in the first trimester of pregnancy in 17% of women with a habitual miscarriage of different genesis with ultrasound revealed predlozhenie branched chorion or placenta. During the development of pregnancy in most cases, the "migration" of the placenta is observed, which usually ends in the 16-24 weeks of pregnancy.

However, in 2.2% of women, placenta previa remains stable. In 65% of women with chorion presentation outside of pregnancy, there were pronounced hormonal, anatomical disorders: inadequate luteal phase, hyperandrogenia, genital infantilism, chronic endometritis, intrauterine synechia. Malformations of the uterus were detected in 7.7% of women. In 7.8% of cases, the first pregnancy was observed after prolonged infertility treatment of hormonal genesis.

The course of pregnancy in 80% of women with presentation of the branching chorion was characterized by frequent bloody discharge without signs of an increase in the contractile activity of the uterus.

As the "migration" of the placenta ceased bloody discharge. However, in women with a stable presentation of the placenta, bleeding periodically resumed at all stages of the development of pregnancy. In 40% of them, anemia of varying severity is noted.

Since in pregnant women with miscarriages, the presentation of the chorion / placenta is often detected, it is necessary to carry out pathogenetically substantiated rehabilitation therapy for pregnancy preparation outside pregnancy.

In the first trimester, in case of presentation of the presentation of the branching chorion, it is necessary to carry out dynamic monitoring by means of ultrasound and prevention of placental insufficiency. In the absence of the phenomena of "migration" of the placenta, with its stable presentation, it is necessary to discuss the patient's question about the regimen, the possibility of rapid hospitalization in case of bleeding, the possibility of staying in a hospital, etc.

It can not be said that the problem of premature detachment of a normally located placenta does not attract researchers. Nevertheless, many aspects of this problem remain unresolved or controversial in view of the conflicting views on many issues of this severe pathology.

There is conflicting information on the effect on the fetus of the placenta area separated from the uterus wall, on structural and morphofunctional changes, and also on the interpretation of the data.

Disputable views on the nature of the change in myometrium in this pathology. The frequency of this pathology in the population ranges from 0.09 to 0.81%. It should be noted that the reason for the detachment can be very difficult to establish. The analysis of the data showed that 15.5% of women had an abstinence with toxicosis of the second half of pregnancy, or hypertension of another genesis. The rest noted polyhydramnios, multiple pregnancies, anemia, late amniotomy. In 17.2% of pregnant women, it was not possible to identify or even suggest the cause of this pathology. In 31.7% of women, the detachment occurred in the process of premature birth, in 50% it preceded the onset of labor. In 18.3% of women with placental abruption there were no signs of labor in the future.

Anomalies of the placenta itself (placenta circumvaelate, placenta marginata) are traditionally associated with premature loss of pregnancy.

Anomalies of the hemochoric placenta do not always accompany the chromosomal pathology of the fetus. It is believed that complications of pregnancy such as eclampsia, intrauterine growth retardation and frequent placental abruption are linked pathogenetically by a single mechanism - an abnormality of the placenta due to the limitation of the depth of infestation. In the place of contact of the placenta with the uterus, there are factors that increase or limit growth, there is a very thin balance of cytokines that controls the depth of the invasion. Th2, cytokines and growth factors such as colony stimulating growth factor 1 (CSF-1) and il-3 increase trophoblast invasion, while Th1 cytokines limit it (via il-12, TGF-p. Macrophages play the role of regulator of this process , limiting the action of il-10 and IFN.-The placenta is a developing organ in the process of the first trimester, and if the cytokine balance is violated towards factors such as il-12, 1TGF-P, IFN-y, these disorders limit the invasion of trophoblast, This disrupts the normal development of the trophoblast to the spiral arteries and is not properly formed If the invasion is deficient, increased pressure in the maternal spiral arteries can disrupt the thin layer of the trophoblast.If the detachment becomes worse, the pregnancy will be lost.If the detachment is partial, then placental insufficiency develops with intrauterine growth retardation and pregnancy-induced hypertension.

Apoptosis in the placenta increases as it develops and possibly plays a role in its development and aging. Premature induction of apoptosis can contribute to placental dysfunction and, as a result, loss of pregnancy. In the study of placenta in women with spontaneous abortion and induced, a significant decrease in proteins inhibiting apoptosis was found. It is believed that impaired production of placenta proteins can lead to early development of apoptosis and abortion.

[1], [2], [3], [4], [5], [6]