Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies

Abstract

Background Cesarean scar pregnancy (CSP) is defined as a gestational sac or trophoblast implanted within the previous cesarean scar (CS). The study aimed to investigate the mechanism of CSP. Methods We collected the decidua tissues of CSP patients from cesarean scar (n = 25) or uterine cavity of the same women (n = 25) at department of Gynecology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology from July to December 2023. Morphological changes and angiogenesis in the decidua tissues were examined. And we studied the expression of the factors related to endometrial recovery. Scanning electron microscope was used to detect the number of pinopodes. Results The decidua tissues in the CSP-uterine scar group have more diffuse lymphocyte infiltration compared to CSP-cesarean cavity group. The vessel density (31.95 vessels/mm²) was significantly decreased in CSP-uterine scar group compared to CSP-cesarean cavity group (69.4 vessels/mm², P<0.01). The vascular surface (0.0180 ± 0.0018 mm²/mm²) and luminal surface (1,871.00 ± 352.65 m²/vessel) was significantly smaller in CSP-uterine scar group compared to CSP-cesarean cavity group (0.0550 ± 0.0031 mm²/mm² and 2,930.00 ± 548.14 m²/vessel, P<0.01). Compared to CSP-cesarean cavity group (7.00 ± 1.00), the number of pinopodes in CSP-uterine scar group were significantly decreased (0.33 ± 0.58). The expression of CD56, IL-6 and IL-1βin CSP-uterine scar group were significantly lower than those in CSP-cesarean cavity group. Conclusions There were lower angiogenesis and endometrial receptivity in cesarean scar decidua tissuess. The changes in the vascular pattern of cesarean scar decidua tissues may be beneficial for embryo implantation.