Remodeling of the villous chorion in pregnant women at 19–25 weeks of gestation after coronavirus disease (COVID-19) in cases of live-term fetal birth and antenatal fetal death
Year: 2026
Type: article
Study design: Observational Study
Abstract: Aim. To investigate the features of villous chorion remodeling after coronavirus disease (COVID-19) at 19–25 weeks of gestation in cases of live-term fetal birth and antenatal fetal death. Materials and methods. The study included placentas from live-born infants (Group I, n = 92), placentas from cases of antenatal fetal death (Group II, n = 12), and a comparison group comprising placentas from live-born infants (n = 54) as well as placentas from cases of antenatal fetal death, subdivided into subgroup I-A (ischemic placental dysfunction) and subgroup II-A (placentitis). Maternal COVID-19 infection was confirmed by a positive polymerase chain reaction test detecting SARS-CoV-2 RNA. Histological examination, immunohistochemistry using monoclonal antibodies against CD31 and α-smooth muscle actin (α-SMA), morphometric analysis, and statistical methods were performed. Results. In Group II and subgroups I-A and II-A, the gestational age was lower compared with Group I and the control group (p < 0.001). Placental examination in Groups I and II and subgroup I-A revealed an increased proportion of stem and intermediate villi – 33 (23; 46), 36 (25; 50), and 30 (22; 48), respectively – and a decreased proportion of terminal chorionic villi – 17 (15; 18), 8 (7; 8), and 10 (9; 14), respectively (p < 0.001). In the capillary walls of terminal villi in Groups I and II, α-SMA-positive pericytes were identified, indicating the acquisition of myofibroblast-like properties. In Group I, vascular remodeling of the stem villi was characterized by smooth muscle cell proliferation and their transition to a synthetic phenotype. In Group II and subgroup I-A, degenerative changes in the smooth muscle cells of stem villous arterioles and pathological neovascularization of obliterated vessels were observed. Placentas from pregnancies complicated by COVID-19 were characterized by stromal edema of the terminal villi, proliferative changes in the vascular wall (Group I), and a high density of obliterated vessels together with stromal fibrosis of the stem villi (Group II). Conclusions. Remodeling of the villous chorion in pregnant women at 19–25 weeks of gestation after COVID-19 was characterized by delayed development. Structural changes in the vascular and stromal components of the villi were associated with transformation of the phenotypic characteristics of smooth muscle cells and pericytes. COVID-19 in pregnant women at 19–25 weeks of gestation induced the development of distinct morphological changes resembling those observed in placental ischemic dysfunction.
Source: Pathologia
Authors: T. V. Savchuk, I. V. Leshchenko
Institution: Bogomolets National Medical University
Language: English
Subfield: Obstetrics and Gynecology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7221511231