The objective: to study the immunohistochemical features of placenta in women with premature birth in 28–33 weeks of pregnancy. Materials and methods. 120 pregnant women (the main group) who were hospitalized and delivered in the Kyiv Perinatal Center during 2018–2020 at a gestation period of 23–33 weeks were examined. The women of the main group were divided into two subgroups depending on the term of birth – the 1st group included patients who delivered at 23–28 weeks of pregnancy, the patients of the 2nd group had labors at 29–33 weeks. Placentas of women in the main group were examined using morphological (histological method – staining with hematoxylin and eosin and van Gieson) and immunohistochemical methods (indirect streptavidin-peroxidase method for determining the expression level of progesterone receptors – PR). Results. Premature maturation of chorionic villi was found in 40 % of placentas of women in the 1st group 1, in 20 % – blood circulation disorders and the presence of acute inflammatory infiltration in the fetal membranes, decidual and chorionic membranes, 10 % – pathological immaturity of the placenta according to the variant of chaotic sclerosed villi. During the immunohistochemical study of RP, an unexpressed reaction was found in the epithelium and stromal cells of stem, intermediate and terminal villi – 1 point; in fetal membranes and extravillous cytotrophoblast – 2 points; in the endothelium of vessels – 0–1 point. In the placentas of women in the 2nd group premature maturation of villi was found in 70 % of cases, pseudoinfarcts of villi which are embedded in fibrinoid occupying a significant area – 45 %, afunctional zones – 55 %, blood circulation disorders – 35 %, pathological immaturity placenta according to the variant of chaotic, sclerosed villi – 20 %, acute inflammatory infiltration in the fetal membranes – 15 %. Immunohistochemical analysis of the placental barrier revealed the highest expression of RP in the nuclei of decidual cell which belong to the maternal structure. It should be noted the presence of expression of progesterone receptors in stem villi, fibroblasts and nuclei of the vessel wall. Minimal or absent expression was determined in the nuclei of other villous structures and their vessels. Conclusions. It was established that the receptivity of progesterone has its own characteristics in placental structures depending on the gestation period, which is an important factor in the choice of management for the prevention and reduction of perinatal losses for this contingent of pregnant women.

Endometriosis is one of the most relevant problems in modern gynecology. This pathology often leads not only to structural and functional changes in the reproductive system and cause infertility (35-50 %), but also generally significantly worsens physical health, the work capacity and can affect the psycho-emotional state of women. As endometriosis is diagnosed in almost every third of women and there is a trend for its rate increase, it remains a subject of special interest not only for scientists, but also for practical doctors. Despite of a lot of literature data, currently, there is no protocol, international guideline, which provides uniform algorithms for the diagnosis and treatment of endometriosis with subsequent realization of reproductive function. The experts pay attention to an individual approach for the comprehensive solution of the problem regarding the age of the woman, the localization and extent of the process, the severity of symptoms, the state of fertility and the necessity to restore reproductive function, the presence of concomitant gynecological and somatic pathology, and the effectiveness of previous treatment. The article provides a clinical description of a case of spontaneous pregnancy with bilateral endometriosis of the ovaries, which was diagnosed before pregnancy, with favorable maternal and fetal outcomes. An ultrasound description of endometrioid changes in the pelvic organs during the pregnancy is presented. The authors developed an individual management plan for the patient in accordance with her young age, high ovarian reserve, which in the presence of patency of the fallopian tubes and normal indicators of the man’s spermogram can be considered as prognostic factors for evaluating the appropriate reaction of the ovaries in case of spontaneous conception. During the operative delivery (caesarean section), the surgical treatment of endometriosis of the ovaries was performed at the same time. The patient and the newborn were discharged from the hospital under the supervision of a gynecologist in a satisfactory condition.