Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies

Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies Yu Liu, Xixiang Ma, Xin Du, Jing Jin, Yizhen Cui, Jianshan Zhou, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4448007/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 30 Sep, 2025 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted 16 You are reading this latest preprint version 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/mm 2 ) was significantly decreased in CSP-uterine scar group compared to CSP-cesarean cavity group (69.4 vessels/mm 2 , P <0.01). The vascular surface (0.0180 ± 0.0018 mm 2 /mm 2 ) and luminal surface (1,871.00 ± 352.65 m 2 /vessel) was significantly smaller in CSP-uterine scar group compared to CSP-cesarean cavity group (0.0550 ± 0.0031 mm 2 /mm 2 and 2,930.00 ± 548.14 m 2 /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. angiogenesis endometrial receptivity decidua cesarean scar pregnancy Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Cesarean scar pregnancy (CSP) is defined as a gestational sac or trophoblast implanted within the previous cesarean scar (CS) [ 1 ]. CS has caused complications, such as CSP, placenta accreta spectrum (PAS), and compromised fertility [ 2 ]. CSP is one of the most severe complication of CS with 4.2% of ectopic pregnancies are CSP and 1 in 531 women with cesarean section scars have a CSP [ 3 ]. CS is increasing worldwide in the last decades, and a parallel rise in the rate of CSP. CSP is considered to be a life-threatening disease with a high risk of uncontrolled bleeding and uterine rupture and serious consequences for future fertility of the patient. Currently, CSP remains relatively rare, and the majority of studies on CSP are likely to be published as case reports or case series. Moreover, little is known about the pathophysiology of CSP. CSP can be subdivided into endogenous (growth toward the uterine cavity) and exogenous (growth toward the myometrium and uterine serosal layer) [ 4 ]. The latter is more likely to lead to uterine rupture and severe bleeding. The removal of pregnancy at scar sites can be done by hysteroscopic or laparoscopic surgery, and transcervical vacuum suction has also been proposed as a minimally invasive treatment option [ 5 ]. CSP development is associated with embryo implantation in cesarean scar. Embryo implantation is a complex physiological process, and requires the vascular supply of nutrients. Therefore, angiogenesis-related factors and endometrial receptivity at the implantation site may be correlated to CSP. Physiological angiogenesis is important in embryo implantation and placenta formation. Angiogenesis in the decidua includes proliferation, migration, and vascular permeability [ 6 ]. Angiogenesis is promoted by basic fibroblast growth factor (bFGF) and its receptors, vascular endothelial growth factor (VEGF) and its receptors (VEGFR), placental growth factor (PlGF), and other growth factors. VEGF and PlGF are mostly well-known angiogenic factor. PlGF enhances VEGF signaling, they have synergistic effects [ 7 ]. Some study reported that VEGF or its receptors defect mice have no vascular network and thus abort [ 8 ]. Moreover, when VEGF/VEGFR-2 signaling pathway is impaired, PlGF may shift to severe inflammation and cause tissues damages which could lead to early pregnancy losses [ 9 ]. Studies have reported that angiopoietin (Ang) and its receptors (TIE-2) have been involved in regulating angiogenesis [ 10 ]. Therefore, angiogenesis and embryo implantation are closely correlated. Endometrial receptivity is crucial for successful embryo implantation [ 11 ]. Human embryo implantation including apposition, adhesion and invasion process. Pinopod is one of the endometrial morphological features and as marker of embryo implantation [ 12 ]. MUC1 is a glycoprotein, and an important adhesion factors. Aplin et al. found that MUC1 was up-regulated during the peri-implantation period [ 13 ]. IL-6 is a pleiotropic cytokine, and activating the immunoglobulin production. IL-6 and IL1βis endometrial receptivity-related factors. In the present study, we assumed that angiogenesis and endometrial receptivity may be related to the development of CSP, and changes in local endometrial receptivity and angiogenesis at the cesarean incision site may favor preferential implantation of embryos. Therefore, this study aimed to detected to endometrial receptivity and angiogenesis in the decidua of same CSP women from uterine cavity and cesarean scar. Materials and Methods Samples collection For this study, the decidua tissuess were obtained from patients who underwent transcervical vacuum suction of the CSP with fetal heart and buds at<10 weeks of gestation, from July to december 2023, at department of Gynecology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology. All patient’s inclusion criteria: Previous cesarean section and transvaginal ultrasound features, including the implantation of the amniotic sac on a scar with progression of the pregnancy in the cervico-isthmic space and in the uterine cavity. Exclusion criteria: inevitable miscarriage, abnormal pregnancy, missed abortion. Group A: the decidua of CSP women were collected from cesarean scar (n = 25); Group B: the decidua of CSP women were collected from uterine cavity of the same women (n = 25). The study was approved by the Ethics Committee of Reproductive Medicine Center, Tongji Medical College, Huazhong University of Science and Technology ([2023IEC(123)NO]). Written informed consent forms were obtained from each participant. Hematoxylin-Eosin staining Decidua tissuess were obtained from patients and fixed in a 10% formaldehyde solution. Then the samples were processed to paraffin blocks according to the standard procedure. 5µm sections were cut and stained with Hematoxylin-Eosin (HE) after being dewaxed and rehydrated. Scanning electron microscope Human decidua tissuess were fixed in electron microscopy fixative at 4℃. Human decidua tissuess were dehydrate in ethanol gradient and then isoamyl acetate for 15 min. The samples were observed with a Scanning electron microscope. Immunohistochemistry After being dewaxed and rehydrated, the 5µm thick sections were microwaved in 0.01 M sodium citrate buffer (pH = 6.0) for antigen retrieval, then cooled down to room temperature. The sections were washed in PBS three times (10min per time), and endogenous peroxidase activity was blocked with 3% H 2 O 2 in PBS. The sections were blocked in blocking solution (containing 3% normal goat serum and 3% fetal bovine serum in 1% bovine serum albumin) for 1 h and were incubated with primary antibodies, including primary antibodies against CD34 (ab13840; Abcam), in a humidified box overnight at 4°C. After three times washes in PBS, sections were then incubated with peroxidase-labeled secondary antibody (Goat Anti-Mouse IgG, A21010; Goat Anti-Rabbit IgG, A21020; Abbkine) for 1h at room temperature and counterstained with hematoxylin. Images were photographed with an Axio Scope A1 microscope (Zeiss, Germany). Statistical analysis Data were described as mean ± standard deviation (Mean ± SD) or Q2 (Q1, Q3). Statistical analyses were performed by t test or one-way ANOVA using the statistical software SPSS 12.0. P < 0.05 was considered statistically significant. Results Clinical characteristics The clinical characteristics of 25 patients with CSP are presented in Table 1 . The median age was 33.0 years (Q1, Q3:30.0,36.0), the median BMI was 21.83kg/m 2 (Q1, Q3:20.20,23.93). The median delivery and pregnant times were 4 and 1. The median number of prior CS was 1. The median abortion times was 2, and gestational sac diameter was 2.40 cm. Table 1 Patient characteristics Characteristic CSP(n = 25) Age(years) 33.0 (30.0 ~ 36.0) BMI(Kg/m 2 ) 21.83 (20.20 ~ 23.93) Delivery (times) 4.00 (3.00 ~ 5.00) Pregnant (times) 1.00 (1.00 ~ 2.00) Number of prior CS (times) 1.00 (1.00 ~ 2.00) Abortion (times) 2.00 (1.00 ~ 3.00) Gestational sac diameter (cm) 2.40 (1.70 ~ 3.60) CS, cesarean section;Values are presented as Q2(Q1,Q3). Comparison of decidua tissues in cesarean scar and non-scar The results of HE staining proved that decidua tissues in the CSP-uterine scar group have more diffuse lymphocyte infiltration compared to CSP-cesarean cavity group (Fig. 1 ). Moverover, a small amount of epithelial cell watery degeneration can be seen locally in the decidua tissues of cesarean scar, with swelling of cells and loose cytoplasm with light staining (Fig. 1 ). The expression of angiogenesis factors in cesarean scar and non-scar decidua tissues In cesarean scar and CSP-cesarean cavity group, we detected the CD34 staining, and there was no different in the intensity (Figrue2A). Vessel density was significantly decreased in CSP-uterine scar group (31.95 vessels/mm 2 ) compared to CSP-cesarean cavity group (69.40 vessels/mm 2 , P <0.01, Figrue2B). The vascular surface was significantly smaller in CSP-uterine scar group (0.0180 ± 0.0018 mm 2 /mm 2 ) compared to CSP-cesarean cavity group (0.0550 ± 0.0031 mm 2 /mm 2 , P <0.01, Figrue2C). And the luminal surface was significantly smaller in CSP-uterine scar group (1,871.00 ± 352.65 m 2 /vessel) compared to CSP-cesarean cavity group (2,930.00 ± 548.14 m 2 /vessel, P <0.05, Figrue2D). The number of pinopodes in cesarean scar and non-scar decidua tissues SEM was used to detect the number of pinopodes in cesarean scar and CSP-cesarean cavity group. The result show that compared to CSP-uterine scar group (0.33 ± 0.58, Fig. 3 A and B), the number of pinopodes in CSP-cesarean cavity group were significantly increased (7.00 ± 1.00, Fig. 3 A and B, P <0.05). These results suggest that cesarean scar tissues have fewer the formation of pinopodes. The expression of MUC1, CD56, IL6 and ILβin cesarean scar and non-cesarean scar decidua tissues The expression of MUC1, biomarker of endometrial receptivity, were detected in cesarean scar and non-scar decidua tissues. Immunohistochemical result show that the expression levels of MUC1 in CSP-uterine scar group were higher than those in CSP-cesarean cavity group (Fig. 4 A and B, P >0.05). CD56 is a marker of NK cells.The expression levels of CD56 in CSP-uterine scar group were significantly lower than those in CSP-cesarean cavity group (Fig. 4 A and B, P <0.05). IL-6 and IL-1βare closely related to endometrial receptivity and implantation. The results show that IL-6 and IL-1βin CSP-uterine scar group were significantly lower than those in CSP-cesarean cavity group (Fig. 4 A and B, P <0.05). These findings suggest that cesarean scar tissues have poorly the endometrial receptivity. Discussion In this study, our results indicated that differences in patterns of vascularization between cesarean scar and non-scar decidua tissues. In cesarean scar decidua tissues, the vessel density, vascular surface and luminal surface were decreased. Furthermore, there were lower the number of pinopodes and the expression levels of endometrial receptivity-related genes in cesarean scar compared to non-scar decidua tissues. Angiogenesis and embryonic development are closely correlated. In our study, we found that the decrease of vessel density, vascular surface, and luminal surface in cesarean scar decidua tissues. A study reported that the increase of vessel density may be related to the increased blood flow during pregnancy [ 14 ]. The cesarean scar decidua tissues has little blood flow. That data suggest that impaired blood circulation around the scar. The formation of adverse blood vessels in the scar area may cause or contribute to permanent focal myometrial degeneration, as well as reduced or absent epithelial regeneration in the scar area. Moreover, microscopic damage of the endometrium may lead to abnormal villous tissues adhesion or even invasion. Current literature supports that angiogenesis is an essential physiological component of implantation, and embryonic development [ 15 ]. Therefore, the changes in the vascular pattern of cesarean scar decidua tissues may be beneficial for embryo implantation. Furthermore, our results suggested that in cesarean scar decidua tissues, there were lower endometrial receptivity. Endometrial receptivity is closely related to embryo implantation, which can be evaluated by counting pinopodes numbers and detecting the expression of the MUC1, CD56, IL-6 and IL-1β. And the pinopodes are appears during the window of embryo implantation[ 16 ]. In our study, cesarean scar decidua tissues was lower pinopodes number and endometrial receptivity in cesarean scar decidua tissues. This may be not the reason for embryo implantation in cesarean scar. Conclusion, the current study indicated that there were lower angiogenesis and endometrial receptivity in cesarean scar compared to non-scar decidua tissues. These results suggest that the changes in the vascular pattern of cesarean scar decidua tissues may be beneficial for embryo implantation. Declarations Funding This work was supported by Hubei Province Health Commission scientific research project (WJ2023M112), Maternal and Child Health Hospital of Hubei Province Research Project (grant number 2023SFYY010) and Maternal and Child Health Hospital of Hubei Province Research Project (grant number 2023SFYM012). Competing Interests None declared. Author contribution statement Y. L. collected samples, conducted the statistical analysis and wrote the manuscript. X.M. conducted the statistical analysis. X.D., J.J. Z.J. and S.G. collected samples and prepared the pictures and revised the manuscript. Y.C. and H.L. took part in discussed the results. Y.L. designed experiments and revised the manuscript. All authors read and approved the manuscript. Data Availability declaration The main data of this study can be directly requested from the corresponding author. References Shah P, et al. Ruptured Cesarean Scar Pregnancy: A Case Report. JNMA J Nepal Med Assoc. 2019;57(217):209–12. Cali G, et al. Outcome of Cesarean scar pregnancy managed expectantly: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2018;51(2):169–75. Fylstra DL. Ectopic pregnancy within a cesarean scar: a review. Obstet Gynecol Surv. 2002;57(8):537–43. Vial Y, Petignat P, Hohlfeld P. Pregnancy in a cesarean scar. Ultrasound Obstet Gynecol. 2000;16(6):592–3. De Braud LV, et al. Risk prediction of major haemorrhage with surgical treatment of live cesarean scar pregnancies. Eur J Obstet Gynecol Reprod Biol. 2021;264:224–31. Goodger AM, Rogers PA. Uterine endothelial cell proliferation before and after embryo implantation in rats. J Reprod Fertil. 1993;99(2):451–7. Luttun A, et al. Revascularization of ischemic tissuess by PlGF treatment, and inhibition of tumor angiogenesis, arthritis and atherosclerosis by anti-Flt1. Nat Med. 2002;8(8):831–40. Demir R, Yaba A, Huppertz B. Vasculogenesis and angiogenesis in the endometrium during menstrual cycle and implantation. Acta Histochem. 2010;112(3):203–14. Nejabati HR, et al. Placental growth factor (PlGF) as an angiogenic/inflammatory switcher: lesson from early pregnancy losses. Gynecol Endocrinol. 2017;33(9):668–74. Geva E, Jaffe RB. Role of angiopoietins in reproductive tract angiogenesis. Obstet Gynecol Surv. 2000;55(8):511–9. Zygmunt M, et al. Angiogenesis and vasculogenesis in pregnancy. Eur J Obstet Gynecol Reprod Biol. 2003;110(Suppl 1):S10–8. Achache H, Revel A. Endometrial receptivity markers, the journey to successful embryo implantation. Hum Reprod Update. 2006;12(6):731–46. Aplin JD, Hey NA, Graham RA. Human endometrial MUC1 carries keratan sulfate: characteristic glycoforms in the luminal epithelium at receptivity. Glycobiology. 1998;8(3):269–76. Kam EP, et al. The role of trophoblast in the physiological change in decidual spiral arteries. Hum Reprod. 1999;14(8):2131–8. Sherer DM, Abulafia O. Angiogenesis during implantation, and placental and early embryonic development. Placenta. 2001;22(1):1–13. Quinn CE, Casper RF. Pinopodes: a questionable role in endometrial receptivity. Hum Reprod Update. 2009;15(2):229–36. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 30 Sep, 2025 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted Editorial decision: Revision requested 18 Jun, 2025 Reviews received at journal 08 Jun, 2025 Reviewers agreed at journal 29 May, 2025 Reviews received at journal 12 Apr, 2025 Reviews received at journal 11 Apr, 2025 Reviewers agreed at journal 11 Apr, 2025 Reviewers agreed at journal 06 Apr, 2025 Reviewers agreed at journal 08 Mar, 2025 Reviews received at journal 24 Feb, 2025 Reviewers agreed at journal 24 Feb, 2025 Reviewers agreed at journal 16 Jul, 2024 Reviewers invited by journal 16 Jul, 2024 Editor invited by journal 27 May, 2024 Submission checks completed at journal 24 May, 2024 Editor assigned by journal 24 May, 2024 First submitted to journal 20 May, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4448007","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":308581215,"identity":"b4c0a15b-68c9-493a-8ed5-2ebce0f48775","order_by":0,"name":"Yu Liu","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"","lastName":"Liu","suffix":""},{"id":308581220,"identity":"dacfde2e-0800-49bd-b3f3-45ab01a0f0c5","order_by":1,"name":"Xixiang Ma","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xixiang","middleName":"","lastName":"Ma","suffix":""},{"id":308581222,"identity":"0c481622-f439-49ab-bf2f-5ec28ff4aed7","order_by":2,"name":"Xin Du","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xin","middleName":"","lastName":"Du","suffix":""},{"id":308581223,"identity":"0eeaad0a-2824-4bb0-a6c2-82409564a70c","order_by":3,"name":"Jing Jin","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Jin","suffix":""},{"id":308581224,"identity":"d4ba1e2b-ed9f-44db-b8a1-8bfc91e33560","order_by":4,"name":"Yizhen Cui","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Yizhen","middleName":"","lastName":"Cui","suffix":""},{"id":308581225,"identity":"c76b9aae-85ea-4832-9704-4d8a95e2b75c","order_by":5,"name":"Jianshan Zhou","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jianshan","middleName":"","lastName":"Zhou","suffix":""},{"id":308581226,"identity":"5c3ccb6d-8e6e-435b-8687-e8228437a999","order_by":6,"name":"Guanglin Song","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Guanglin","middleName":"","lastName":"Song","suffix":""},{"id":308581227,"identity":"0973a525-a824-4630-8105-de8fbb653d04","order_by":7,"name":"Huiman Li","email":"","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Huiman","middleName":"","lastName":"Li","suffix":""},{"id":308581229,"identity":"5814a3db-aa07-4442-9259-9142c2935951","order_by":8,"name":"Yan Lei","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAqUlEQVRIiWNgGAWjYBACfvbmgw8+GPyTI16LZM+xZMMZBQeMiddicCNHTZrnw4HEBhJsOcMmOcPgTnrf8QTGDx9ziNDCz9572OKDwbPcmWceMEvO3EaULecSb84wYM7dcCOBjZmXGC1AvxhI8xgwpxuQosUIqOVwAvFaIIFskGY488zDZuL8AonKPzbyfMeTD374SIwWBCAlamBaEkjVMQpGwSgYBSMFAAADtUAJsVTOmwAAAABJRU5ErkJggg==","orcid":"","institution":"Huazhong University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Yan","middleName":"","lastName":"Lei","suffix":""}],"badges":[],"createdAt":"2024-05-20 09:14:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4448007/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4448007/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12884-025-08113-x","type":"published","date":"2025-09-30T15:56:58+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":58143476,"identity":"21429b98-a632-4fae-a84e-a02f4ec9741c","added_by":"auto","created_at":"2024-06-11 18:20:49","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":681869,"visible":true,"origin":"","legend":"\u003cp\u003eThe morphological changes\u003cstrong\u003e \u003c/strong\u003eof decidua with Haematoxylin and Eosin Staining\u003cstrong\u003e \u003c/strong\u003ein cesarean scar and non-scar tissues. Bar = 100 μm.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4448007/v1/e12c868130a539b6d3dbb13f.png"},{"id":58143474,"identity":"0dc1cd48-47df-4093-bd63-eb398985e277","added_by":"auto","created_at":"2024-06-11 18:20:49","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":6034792,"visible":true,"origin":"","legend":"\u003cp\u003eVascularization pattern in cesarean scar and non-scar decidua tissues. The vascularization pattern was determined by image analysis of anti-CD34-stained. A. Representative image of CD34 IHC. B. Number of vessels per mm\u003csup\u003e2\u003c/sup\u003e, vascular surface per area (mm\u003csup\u003e2\u003c/sup\u003e/mm\u003csup\u003e2\u003c/sup\u003e) and luminal surface (m\u003csup\u003e2\u003c/sup\u003e/vessel). Bar = 200 μm.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4448007/v1/4bc21379de774a9f803cda9b.png"},{"id":58143473,"identity":"fa1ab024-7891-4717-83c9-6aefdc07aef3","added_by":"auto","created_at":"2024-06-11 18:20:49","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":5534064,"visible":true,"origin":"","legend":"\u003cp\u003eThe morphology and number of pinopodes of decidua\u003cstrong\u003e \u003c/strong\u003ein cesarean scar and non-scar tissues. A. Representative image of scanning electron microscope. B. The number of pinopodes in cesarean scar and non-scar decidua.Bar = 50 μm and 15μm, respectively.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4448007/v1/ef150785af7bed1f65bbdfbd.png"},{"id":58145053,"identity":"b1eb08e2-5343-4f86-84bb-e36e727bac24","added_by":"auto","created_at":"2024-06-11 18:28:49","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":12577639,"visible":true,"origin":"","legend":"\u003cp\u003eThe endometrial receptivity in cesarean scar and non-scar decidua tissues. A. The\u003cstrong\u003e \u003c/strong\u003eendometrial receptivity was determined by image analysis of anti-MUC1-stained, anti-CD56-stained, anti-IL6-stained anti-and ILβ-stained. B. The average optical density in cesarean scar and non-scar decidua tissues. Bar = 100 μm.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4448007/v1/5ed024dc76bd1453fe4deca9.png"},{"id":92883628,"identity":"2234cc3f-e9cb-4362-9787-6852d5ad1a71","added_by":"auto","created_at":"2025-10-06 16:06:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":28980146,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4448007/v1/eb2afa98-89f0-4732-8097-23ce3d297939.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCesarean scar pregnancy (CSP) is defined as a gestational sac or trophoblast implanted within the previous cesarean scar (CS) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. CS has caused complications, such as CSP, placenta accreta spectrum (PAS), and compromised fertility [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. CSP is one of the most severe complication of CS with 4.2% of ectopic pregnancies are CSP and 1 in 531 women with cesarean section scars have a CSP [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. CS is increasing worldwide in the last decades, and a parallel rise in the rate of CSP. CSP is considered to be a life-threatening disease with a high risk of uncontrolled bleeding and uterine rupture and serious consequences for future fertility of the patient. Currently, CSP remains relatively rare, and the majority of studies on CSP are likely to be published as case reports or case series. Moreover, little is known about the pathophysiology of CSP.\u003c/p\u003e \u003cp\u003eCSP can be subdivided into endogenous (growth toward the uterine cavity) and exogenous (growth toward the myometrium and uterine serosal layer) [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The latter is more likely to lead to uterine rupture and severe bleeding. The removal of pregnancy at scar sites can be done by hysteroscopic or laparoscopic surgery, and transcervical vacuum suction has also been proposed as a minimally invasive treatment option [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. CSP development is associated with embryo implantation in cesarean scar. Embryo implantation is a complex physiological process, and requires the vascular supply of nutrients. Therefore, angiogenesis-related factors and endometrial receptivity at the implantation site may be correlated to CSP.\u003c/p\u003e \u003cp\u003ePhysiological angiogenesis is important in embryo implantation and placenta formation. Angiogenesis in the decidua includes proliferation, migration, and vascular permeability [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Angiogenesis is promoted by basic fibroblast growth factor (bFGF) and its receptors, vascular endothelial growth factor (VEGF) and its receptors (VEGFR), placental growth factor (PlGF), and other growth factors. VEGF and PlGF are mostly well-known angiogenic factor. PlGF enhances VEGF signaling, they have synergistic effects [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Some study reported that VEGF or its receptors defect mice have no vascular network and thus abort [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Moreover, when VEGF/VEGFR-2 signaling pathway is impaired, PlGF may shift to severe inflammation and cause tissues damages which could lead to early pregnancy losses [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Studies have reported that angiopoietin (Ang) and its receptors (TIE-2) have been involved in regulating angiogenesis [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Therefore, angiogenesis and embryo implantation are closely correlated.\u003c/p\u003e \u003cp\u003eEndometrial receptivity is crucial for successful embryo implantation [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Human embryo implantation including apposition, adhesion and invasion process. Pinopod is one of the endometrial morphological features and as marker of embryo implantation [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. MUC1 is a glycoprotein, and an important adhesion factors. Aplin et al. found that MUC1 was up-regulated during the peri-implantation period [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. IL-6 is a pleiotropic cytokine, and activating the immunoglobulin production. IL-6 and IL1βis endometrial receptivity-related factors.\u003c/p\u003e \u003cp\u003eIn the present study, we assumed that angiogenesis and endometrial receptivity may be related to the development of CSP, and changes in local endometrial receptivity and angiogenesis at the cesarean incision site may favor preferential implantation of embryos. Therefore, this study aimed to detected to endometrial receptivity and angiogenesis in the decidua of same CSP women from uterine cavity and cesarean scar.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSamples collection\u003c/h2\u003e \u003cp\u003eFor this study, the decidua tissuess were obtained from patients who underwent transcervical vacuum suction of the CSP with fetal heart and buds at\u0026lt;10 weeks of gestation, from July to december 2023, at department of Gynecology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology. All patient\u0026rsquo;s inclusion criteria: Previous cesarean section and transvaginal ultrasound features, including the implantation of the amniotic sac on a scar with progression of the pregnancy in the cervico-isthmic space and in the uterine cavity. Exclusion criteria: inevitable miscarriage, abnormal pregnancy, missed abortion. Group A: the decidua of CSP women were collected from cesarean scar (n\u0026thinsp;=\u0026thinsp;25); Group B: the decidua of CSP women were collected from uterine cavity of the same women (n\u0026thinsp;=\u0026thinsp;25). The study was approved by the Ethics Committee of Reproductive Medicine Center, Tongji Medical College, Huazhong University of Science and Technology ([2023IEC(123)NO]). Written informed consent forms were obtained from each participant.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eHematoxylin-Eosin staining\u003c/h2\u003e \u003cp\u003eDecidua tissuess were obtained from patients and fixed in a 10% formaldehyde solution. Then the samples were processed to paraffin blocks according to the standard procedure. 5\u0026micro;m sections were cut and stained with Hematoxylin-Eosin (HE) after being dewaxed and rehydrated.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eScanning electron microscope\u003c/h2\u003e \u003cp\u003eHuman decidua tissuess were fixed in electron microscopy fixative at 4℃. Human decidua tissuess were dehydrate in ethanol gradient and then isoamyl acetate for 15 min. The samples were observed with a Scanning electron microscope.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eImmunohistochemistry\u003c/h2\u003e \u003cp\u003eAfter being dewaxed and rehydrated, the 5\u0026micro;m thick sections were microwaved in 0.01 M sodium citrate buffer (pH\u0026thinsp;=\u0026thinsp;6.0) for antigen retrieval, then cooled down to room temperature. The sections were washed in PBS three times (10min per time), and endogenous peroxidase activity was blocked with 3% H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e in PBS. The sections were blocked in blocking solution (containing 3% normal goat serum and 3% fetal bovine serum in 1% bovine serum albumin) for 1 h and were incubated with primary antibodies, including primary antibodies against CD34 (ab13840; Abcam), in a humidified box overnight at 4\u0026deg;C. After three times washes in PBS, sections were then incubated with peroxidase-labeled secondary antibody (Goat Anti-Mouse IgG, A21010; Goat Anti-Rabbit IgG, A21020; Abbkine) for 1h at room temperature and counterstained with hematoxylin. Images were photographed with an Axio Scope A1 microscope (Zeiss, Germany).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eData were described as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD) or Q2 (Q1, Q3). Statistical analyses were performed by t test or one-way ANOVA using the statistical software SPSS 12.0. \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eClinical characteristics\u003c/h2\u003e \u003cp\u003eThe clinical characteristics of 25 patients with CSP are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The median age was 33.0 years (Q1, Q3:30.0,36.0), the median BMI was 21.83kg/m\u003csup\u003e2\u003c/sup\u003e (Q1, Q3:20.20,23.93). The median delivery and pregnant times were 4 and 1. The median number of prior CS was 1. The median abortion times was 2, and gestational sac diameter was 2.40 cm.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatient characteristics\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCSP(n\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge(years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33.0 (30.0\u0026thinsp;~\u0026thinsp;36.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI(Kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21.83 (20.20\u0026thinsp;~\u0026thinsp;23.93)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDelivery (times)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.00 (3.00\u0026thinsp;~\u0026thinsp;5.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePregnant (times)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.00 (1.00\u0026thinsp;~\u0026thinsp;2.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of prior CS (times)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.00 (1.00\u0026thinsp;~\u0026thinsp;2.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAbortion (times)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.00 (1.00\u0026thinsp;~\u0026thinsp;3.00)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestational sac diameter (cm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.40 (1.70\u0026thinsp;~\u0026thinsp;3.60)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eCS, cesarean section;Values are presented as Q2(Q1,Q3).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eComparison of decidua tissues in cesarean scar and non-scar\u003c/h2\u003e \u003cp\u003eThe results of HE staining proved that decidua tissues in the CSP-uterine scar group have more diffuse lymphocyte infiltration compared to CSP-cesarean cavity group (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Moverover, a small amount of epithelial cell watery degeneration can be seen locally in the decidua tissues of cesarean scar, with swelling of cells and loose cytoplasm with light staining (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eThe expression of angiogenesis factors in cesarean scar and non-scar decidua tissues\u003c/h2\u003e \u003cp\u003eIn cesarean scar and CSP-cesarean cavity group, we detected the CD34 staining, and there was no different in the intensity (Figrue2A). Vessel density was significantly decreased in CSP-uterine scar group (31.95 vessels/mm\u003csup\u003e2\u003c/sup\u003e) compared to CSP-cesarean cavity group (69.40 vessels/mm\u003csup\u003e2\u003c/sup\u003e, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.01, Figrue2B). The vascular surface was significantly smaller in CSP-uterine scar group (0.0180\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0018 mm\u003csup\u003e2\u003c/sup\u003e/mm\u003csup\u003e2\u003c/sup\u003e) compared to CSP-cesarean cavity group (0.0550\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0031 mm\u003csup\u003e2\u003c/sup\u003e/mm\u003csup\u003e2\u003c/sup\u003e, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.01, Figrue2C). And the luminal surface was significantly smaller in CSP-uterine scar group (1,871.00\u0026thinsp;\u0026plusmn;\u0026thinsp;352.65 m\u003csup\u003e2\u003c/sup\u003e/vessel) compared to CSP-cesarean cavity group (2,930.00\u0026thinsp;\u0026plusmn;\u0026thinsp;548.14 m\u003csup\u003e2\u003c/sup\u003e/vessel, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05, Figrue2D).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eThe number of pinopodes in cesarean scar and non-scar decidua tissues\u003c/h2\u003e \u003cp\u003eSEM was used to detect the number of pinopodes in cesarean scar and CSP-cesarean cavity group. The result show that compared to CSP-uterine scar group (0.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and B), the number of pinopodes in CSP-cesarean cavity group were significantly increased (7.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and B, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). These results suggest that cesarean scar tissues have fewer the formation of pinopodes.\u003c/p\u003e\u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eThe expression of MUC1, CD56, IL6 and ILβin cesarean scar and non-cesarean scar decidua tissues\u003c/h2\u003e \u003cp\u003eThe expression of MUC1, biomarker of endometrial receptivity, were detected in cesarean scar and non-scar decidua tissues. Immunohistochemical result show that the expression levels of MUC1 in CSP-uterine scar group were higher than those in CSP-cesarean cavity group (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA and B, \u003cem\u003eP\u003c/em\u003e\u0026gt;0.05). CD56 is a marker of NK cells.The expression levels of CD56 in CSP-uterine scar group were significantly lower than those in CSP-cesarean cavity group (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA and B, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). IL-6 and IL-1βare closely related to endometrial receptivity and implantation. The results show that IL-6 and IL-1βin CSP-uterine scar group were significantly lower than those in CSP-cesarean cavity group (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA and B, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). These findings suggest that cesarean scar tissues have poorly the endometrial receptivity.\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, our results indicated that differences in patterns of vascularization between cesarean scar and non-scar decidua tissues. In cesarean scar decidua tissues, the vessel density, vascular surface and luminal surface were decreased. Furthermore, there were lower the number of pinopodes and the expression levels of endometrial receptivity-related genes in cesarean scar compared to non-scar decidua tissues.\u003c/p\u003e \u003cp\u003eAngiogenesis and embryonic development are closely correlated. In our study, we found that the decrease of vessel density, vascular surface, and luminal surface in cesarean scar decidua tissues. A study reported that the increase of vessel density may be related to the increased blood flow during pregnancy [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The cesarean scar decidua tissues has little blood flow. That data suggest that impaired blood circulation around the scar. The formation of adverse blood vessels in the scar area may cause or contribute to permanent focal myometrial degeneration, as well as reduced or absent epithelial regeneration in the scar area. Moreover, microscopic damage of the endometrium may lead to abnormal villous tissues adhesion or even invasion. Current literature supports that angiogenesis is an essential physiological component of implantation, and embryonic development [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Therefore, the changes in the vascular pattern of cesarean scar decidua tissues may be beneficial for embryo implantation.\u003c/p\u003e \u003cp\u003eFurthermore, our results suggested that in cesarean scar decidua tissues, there were lower endometrial receptivity. Endometrial receptivity is closely related to embryo implantation, which can be evaluated by counting pinopodes numbers and detecting the expression of the MUC1, CD56, IL-6 and IL-1β. And the pinopodes are appears during the window of embryo implantation[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In our study, cesarean scar decidua tissues was lower pinopodes number and endometrial receptivity in cesarean scar decidua tissues. This may be not the reason for embryo implantation in cesarean scar.\u003c/p\u003e \u003cp\u003eConclusion, the current study indicated that there were lower angiogenesis and endometrial receptivity in cesarean scar compared to non-scar decidua tissues. These results suggest that the changes in the vascular pattern of cesarean scar decidua tissues may be beneficial for embryo implantation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Hubei Province Health Commission scientific research project (WJ2023M112), Maternal and Child Health Hospital of Hubei Province Research Project (grant number 2023SFYY010)\u0026nbsp;and\u0026nbsp;Maternal and Child Health Hospital of Hubei Province Research Project (grant number 2023SFYM012).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone declared.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eY. L. collected samples, conducted the statistical analysis and wrote the manuscript. X.M. conducted the statistical analysis. X.D., J.J. Z.J. and S.G. collected samples and prepared the pictures and revised the manuscript. Y.C. and H.L. took part in discussed the results. Y.L. designed experiments and revised the manuscript. All authors read and approved the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe main data of this study can be directly requested from the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eShah P, et al. Ruptured Cesarean Scar Pregnancy: A Case Report. JNMA J Nepal Med Assoc. 2019;57(217):209\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCali G, et al. Outcome of Cesarean scar pregnancy managed expectantly: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2018;51(2):169\u0026ndash;75.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFylstra DL. 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Nat Med. 2002;8(8):831\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDemir R, Yaba A, Huppertz B. Vasculogenesis and angiogenesis in the endometrium during menstrual cycle and implantation. Acta Histochem. 2010;112(3):203\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNejabati HR, et al. Placental growth factor (PlGF) as an angiogenic/inflammatory switcher: lesson from early pregnancy losses. Gynecol Endocrinol. 2017;33(9):668\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeva E, Jaffe RB. Role of angiopoietins in reproductive tract angiogenesis. Obstet Gynecol Surv. 2000;55(8):511\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZygmunt M, et al. Angiogenesis and vasculogenesis in pregnancy. Eur J Obstet Gynecol Reprod Biol. 2003;110(Suppl 1):S10\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAchache H, Revel A. Endometrial receptivity markers, the journey to successful embryo implantation. Hum Reprod Update. 2006;12(6):731\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAplin JD, Hey NA, Graham RA. Human endometrial MUC1 carries keratan sulfate: characteristic glycoforms in the luminal epithelium at receptivity. Glycobiology. 1998;8(3):269\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKam EP, et al. The role of trophoblast in the physiological change in decidual spiral arteries. Hum Reprod. 1999;14(8):2131\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSherer DM, Abulafia O. Angiogenesis during implantation, and placental and early embryonic development. Placenta. 2001;22(1):1\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQuinn CE, Casper RF. Pinopodes: a questionable role in endometrial receptivity. Hum Reprod Update. 2009;15(2):229\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"angiogenesis, endometrial receptivity, decidua, cesarean scar pregnancy","lastPublishedDoi":"10.21203/rs.3.rs-4448007/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4448007/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eCesarean 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.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe collected the decidua tissues of CSP patients from cesarean scar (n\u0026thinsp;=\u0026thinsp;25) or uterine cavity of the same women (n\u0026thinsp;=\u0026thinsp;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.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe 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/mm\u003csup\u003e2\u003c/sup\u003e) was significantly decreased in CSP-uterine scar group compared to CSP-cesarean cavity group (69.4 vessels/mm\u003csup\u003e2\u003c/sup\u003e, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.01). The vascular surface (0.0180\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0018 mm\u003csup\u003e2\u003c/sup\u003e/mm\u003csup\u003e2\u003c/sup\u003e) and luminal surface (1,871.00\u0026thinsp;\u0026plusmn;\u0026thinsp;352.65 m\u003csup\u003e2\u003c/sup\u003e/vessel) was significantly smaller in CSP-uterine scar group compared to CSP-cesarean cavity group (0.0550\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0031 mm\u003csup\u003e2\u003c/sup\u003e/mm\u003csup\u003e2\u003c/sup\u003e and 2,930.00\u0026thinsp;\u0026plusmn;\u0026thinsp;548.14 m\u003csup\u003e2\u003c/sup\u003e/vessel, \u003cem\u003eP\u003c/em\u003e\u0026lt;0.01). Compared to CSP-cesarean cavity group (7.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00), the number of pinopodes in CSP-uterine scar group were significantly decreased (0.33\u0026thinsp;\u0026plusmn;\u0026thinsp;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.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThere 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.\u003c/p\u003e","manuscriptTitle":"Angiogenesis and endometrial receptivity in the decidua of cesarean scar pregnancies","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-11 18:20:44","doi":"10.21203/rs.3.rs-4448007/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-18T04:39:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-08T12:36:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"81347695697188739926696260422622516726","date":"2025-05-29T07:10:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-12T20:22:40+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-11T09:31:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"141242817492728481532447980710482543378","date":"2025-04-11T08:12:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"159852434286330889723307657409718830737","date":"2025-04-06T13:11:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"71194280575176981630876453785016533785","date":"2025-03-08T11:38:11+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-24T11:28:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"292816619330359553753015866793101711595","date":"2025-02-24T10:54:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"236157060572653437712187534179365797330","date":"2024-07-16T04:40:52+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-16T04:32:49+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-05-27T09:06:50+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-05-24T08:17:32+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-05-24T08:17:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2024-05-20T09:12:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"610bea6b-c78d-4a0e-839d-ed65d3be19de","owner":[],"postedDate":"June 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-06T15:59:16+00:00","versionOfRecord":{"articleIdentity":"rs-4448007","link":"https://doi.org/10.1186/s12884-025-08113-x","journal":{"identity":"bmc-pregnancy-and-childbirth","isVorOnly":false,"title":"BMC Pregnancy and Childbirth"},"publishedOn":"2025-09-30 15:56:58","publishedOnDateReadable":"September 30th, 2025"},"versionCreatedAt":"2024-06-11 18:20:44","video":"","vorDoi":"10.1186/s12884-025-08113-x","vorDoiUrl":"https://doi.org/10.1186/s12884-025-08113-x","workflowStages":[]},"version":"v1","identity":"rs-4448007","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4448007","identity":"rs-4448007","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}