POLYPLOIDIES AS MOST COMMON CHROMOSOMAL ABNORMALITIES OF CHORION IN MISSED ABORTION

Aim. To compare the clinical and morphological characteristics of missed abortion with the most frequent variants of chromosomal abnormalities (trisomies and polyploidies) and with a normal chorion karyotype. Materials and Methods. A comparative analysis of the frequency of chromosomal abnormalities of chorion in 273 cases of early pregnancy loss was carried out in St. Petersburg in 2005-2008 and 2015-2019. It was found that within 10 years the frequency and structure of chromosomal abnormalities remained unchanged. In this connection, it was decided to analyze the clinicoanamnestic and morphological data in patients with early missed abortion with the most frequent variants of the chorionic karyotype: group A – normal chorionic karyotype (104 cases), group B – chorionic trisomy (114), group C – chorionic polyploidy (26). Results. History of recurrent miscarriage, chromosomal abnormalities of the chorion and congenital malformations of the fetus during previous pregnancies were reliably more frequent in patients of group A (with a normal chorionic karyotype). In abortion material of group A, the least pronounced inflammatory changes in the endometrium, decidual tissue and chorionic villi were detected, compared with other groups, however, signs of hormonal disorders in the form of insufficient gravid transformation of the endometrium were more common. Trisomies of the chorion were characterized by the highest mean age of the patients, no other clinical and anamnestic peculiarities were observed, morphologically this group was characterized by moderate inflammatory changes in the endometrium and decidual tissue and pronounced edema of the chorionic villi. In chorion polyploidies, chronic endometritis was more often identified anamnestically, and morphologically this group was characterized by the most pronounced inflammatory changes in chorionic villi, more pronounced lymphoid-macrophagal infiltration of the endometrium and decidual tissue with accumulations of a large number of leukocytes in them of microabscess and necrosis types. With this, the length of stay of an unviable gestational sac in the uterine cavity did not differ between the groups. Conclusions. Morphologically, all the studied groups had peculiarities permitting to suspect one or another chromosomal abnormality in case of impossibility to perform a cytogenetic examination. More aggressive inflammatory response in the endometrium in missed abortion in chromosomal abnormalities (especially in polyploidies) may play a role in chronization of the inflammatory process in the endometrium, therefore, such patients should undergo a preconception preparation, when planning the next pregnancy.