Swelling of the placenta causes
Edema of the placenta. Diagnosis of intrauterine infection of the fetus.
Swelling of the placenta - nonspecific response of the organ whenimmunological isoimmunization of the mother due to Rh- or ABO-conflict, diabetes, infection. The leading echographic marker of placental edema is an increase in its thickness by 30-100% or more. There is also an increase in the echogenicity of placental tissue and an increase in sound conductivity.
The first echographic signs of placental edema can appear already in 15-22 weeks of pregnancy. In the case of an immunological conflict, the timing of the onset of placental edema depends on the antibody titer. Most often, echographic signs of hemolytic disease of the fetus develop to 28-33 weeks. These include swelling of the placenta, enlargement of the liver and spleen of the fetus, ascites. In severe cases, hydrothorax appears.
Swelling of the placenta at a diabetes it is observed only at 1/4pregnant women. Along with the increase in the thickness of the placenta, there is an increase in the biometric parameters of the fetus, which indicates the presence of macrosomia. The timing of the onset of placental edema in diabetes mellitus usually varies within 25-30 weeks of pregnancy.
In the last decade there has been an increase in interest specialists to the study of the role intrauterine infection (IUI) inthe formation of pathology of the perinatal period. In Russia, unlike foreign countries, VUI occupies one of the leading places among the causes of perinatal mortality, and in recent years there has been a progressive increase in the proportion of this pathology in the structure of both perinatal and early neonatal mortality. Russian specialists are actively engaged in the search for clinical signs of VUI, including echographic ones, focusing primarily on the placenta].
Infection of the placenta and fruit it is theoretically possible at any time of pregnancy. It should be borne in mind that clinical practice by no means always coincides with theory, since the mechanisms of the occurrence of an IVF and the protective reactions of the mother and fetus have been studied little. Obviously, the presence of an infectious process (acute, subacute, chronic) in the mother does not mean an unambiguous VUI, since numerous barriers prevent the penetration of infectious agents to the fetus. That is why one can not agree with the opinion of M.I. Kuznetsova et al. which describe "typical echographic changes in the placenta, which indicate a high probability of an IUI" and scrapes of the mucous membranes of the urogenital tract of patients are used as an objective marker of infection of the placenta (the main feature in the formation of the group they study). From our point of view, the verification of urogenital infection of a pregnant woman can not be regarded as a criterion for unambiguous infection of the placenta and, especially, infection of the fetus.
Complexity and urgency problems of intrauterine infection leads to the emergence of more and morethe number of works devoted to the search for echographic markers of this pathology. Thus, A.M. Stygary believes that in the II-III trimesters, the swelling of the placenta is often the only marker indicating the possibility of infection. Swelling of the placenta, in his opinion, when infected is most often transient in nature and observed during the period of swing and fading of the disease. The duration of this period is 2-8 weeks.
Other authors to ultrasound markers of intrauterine infection include an abnormal amount of water,spleen hepatomegaly, pyeloectasia, moderately expressed hydrocephalus, hypoplasia of the lung tissue, pathological expansion of the intestinal loops, hyperechoic inclusions in the liver, hyperechoic intestine, widening of the intervillous space, early maturation of the placenta, and also the presence of hyperechoic inclusions in its structure. Unfortunately, none of the listed works have calculated the sensitivity and specificity of each of these features, as well as the frequency of false positive and false negative results. Obviously, without such indicators, the objectivity of research is sharply reduced.
V. G. Anastas'eva and V.A. Zhukov with ultrasound examination 1580 patients at risk forVUI, found an increase in the thickness of the placenta, as well as a significant increase in the echogenicity of its parenchyma in combination with high sound conductivity. The chorionic plate, according to the Ida, was often expanded and had a characteristic (?) Echogenicity. In the subchoral regions of the placenta, a peculiar hypoechogenic necklace was revealed, due to the expansion of the adjacent sections of the intervillous space. Other authors found hyperechoic changes in the basal lamina associated with excessive deposition of the fibrin layer in it. The thickness of the placenta and echogenicity of its parenchyma from the side of the basal layer, according to the authors, are increasing. In the opinion of V.G. Anastas'eva et al. and Т.В. Kiseleva, because of the disturbance of microcirculation in the intervillous space with the VUI, the placenta acquires a characteristic stratification, which is defined by the authors as "cloud-like inhomogeneity".
M.G. Gazazian et al. for complex examination 196 pregnant women in the second trimester identified the followingsigns VUI: an increase in the tone of the myometrium, pathological impurities in the amniotic fluid, the relative polyhydramnios, the discrepancy between the thickness of the placenta and the gestation period.
A.Yu. Dorotenko noted heterogeneity of the parenchyma in the form of a diffuse alternation of hyperihypoechoic sites at normal thickness of the placenta; hyperechoic inclusions in the parenchyma of various echomolarities, revealed up to 28 weeks of pregnancy, combined with an increase in the thickness of the placenta; large anechoic inclusions in irregular parenchyma with distinct contours, combined with thickening of the placenta; anechogenic homogeneous spaces between the hyperechogenic basal membrane and placenta parenchyma. In the opinion of the author, "these echographic changes in the placenta can be considered as echographic signs of the VUI as well as edema of terminal villi; focal necrosis of decidual cells alternating with inflammatory tissue infiltration; foci of ischemia and hemorrhages; fibrinoid deposits; fibrosis in the stroma of terminal villi; focal deposits of lime salts. "
In the studies of A.N. Griban and S.S. Bolkhovitinova analyzed the results of an echographic evaluation of the stage of maturation of the placenta in 637 women whose pregnancy was complicated by an acute infection. The authors found that in acute infection, the mother experienced an earlier maturation of the placenta than in the physiological course of pregnancy.
According to some authors. ultrasound picture of placentaldepends on the stage of the inflammatory process. Swelling of the placenta with an IVF is transient in nature and occurs during the height of the disease. At this time, the placenta becomes uniform and more echogenic, its sound conductivity rises, the reflection from the basal plate disappears, the thickness increases by 20-30%. During the height of the disease, areas of expansion of the intervorsing space of different localization appear, as well as the intra-lobe zone of edema of high echogenicity more pronounced in the center of the catheter-dons. The thickness of the placenta can be doubled compared to the norm. Inverse changes in the placenta are manifested by a gradual decrease in its echogenicity and normalization of thickness and structure. In some cases, after the end of the inflammatory process in the placenta, small-point hyperechoic calcifications and even calcification of the placental septums are determined.
According to the data of I.O. Sidorova et al. with ultrasound placentography in pregnant women of high infectious riskthe following echographic signs of the VUI were revealed: varicose veins of the placenta (87.5%), hyperechoic inclusions in the placenta structure (56.1%), placental edema (50%) and basal plate contrast (18.8%). At the same time, in pregnant women with established infection of the amniotic fluid (according to the results of inoculating amniotic fluid obtained by amniocentesis), the echographic and clinical signs of VUI were much more frequent. In 90.9% of cases, there was a threat of termination of pregnancy, 81.8% of meningitis, 27.3% of CVD, 100% of varicose veins of the placenta, 68.2% of hyperechoic inclusions in the placenta structure, 63 , 6% - swelling of the placenta, in 22,7% - the contrast of the basal plate.
Such high informativity of echography in the diagnosis of the VUI causes some confusion. Indeed, it is difficult to imagine the diagnostic criteria of any pathology in other areas of medicine that are 100% sensible.
In contrast to these studies other authors in the study of informativityultrasound examination in the prediction of the VUI report that in ultrasound placentography in cases of fetal venous insufficiency it is possible to detect premature maturation of the placenta or the appearance of calcifications in only 15% of cases, and the change in the amount of amniotic fluid is only 2% (0.5% in physiological pregnancy) . Thus, according to S.E. Sorokina, the informativity of the echography in forecasting the risk of implementing the VUI is low and does not exceed 50%.
The list of domestic researches. devoted to VUI and echographic features of thispathology can continue. There is no doubt that the problem of VUI exists, since many newborns are born with signs of infection. The trouble is that the limited methods of prenatal diagnosis do not allow to unequivocally prove the connection of the infectious process with the echographic changes in the placenta. We are deeply convinced that a classical scientific study should presuppose a prenatal biopsy of those parts of the placenta that, by ultrasonic characteristics, appear suspicious by the presence of an infectious process. Otherwise, from the point of view of evidence-based medicine, all the features described above can be regarded as subjective opinion of authors about the echographic characteristics of the theoretically "inflamed" placenta.
Another lack of majority published works is the lack of clearechographic criteria in describing those or other changes in the placenta. The concepts of "increased echogenicity," "insignificant thickening," "moderate polyhydramnios," "contrasting the basal plate," and especially "cloud-like inhomogeneity" have nothing in common with rigorous scientific research, since their reproducibility can not be calculated. Moreover, none of the listed authors carried out double-blind studies excluding subjective evaluation of echographic features. It is sad that in modern foreign literature and extensive resource-caxlnternet, devoted to the problems of the VUI, we could not find the results of randomized controlled trials confirming the ultrasound phenomena described above from the standpoint of evidence-based medicine. We hope that such research is ahead. Practical medicine daily proves the need for their conduct. Obviously, only the maximum objectification of echographic criteria, the development of common criteria for evaluating the concept of "intrauterine infection", as well as the introduction of a unified scheme for examining the mother and fetus will make it possible to approach the solution of the problem of VUI.