Extravillous trophoblast invasion and decidualization in cesarean scar pregnancies

Abstract

Introduction:The increasing cesarean section rate has led to an increase in the number of subsequent pregnancies resulting in a cesarean scar pregnancy. There appears to be preferential attachment of the blastocyst to the scar site, which may be associated with defective decidua in that region, resulting in abnormal implantation, which can in turn negatively affect the success of the pregnancy. The aim of the current study was to evaluate the extravillous trophoblast, decidua, and myometrium in scar and adjacent non-scar regions of the implantation site of a cesarean scar pregnancy.Material and Methods: Samples containing a gestational mass were obtained by laparoscopic excision from patients with a cesarean scar pregnancy at 6-11 weeks of gestation as diagnosed by transvaginal or transabdominal ultrasound (n = 8 type II cesarean scar pregnancy). Cesarean scar pregnancy tissues were separated into scar and non-scar regions, and the scar regions were sub-separated into non-implantation and implantation sites. Serial sections were histologically examined after hematoxylin and eosin, Masson's trichrome and immunochemical staining, and changes in the myometrium, extravillous trophoblast, and decidua were evaluated. Results:In cesarean scar pregnancy, compared with scars not in the implantation site, scars in the implantation site displayed increased fibrosis, and had disrupted myometrium, which was related to varying patterns of E-cadherin expression as a response to extravillous trophoblast invasion. In addition, local decidua was found at the non-scar implantation sites, with multinucleated trophoblast giant cell accumulation and shallow invasion. These features were not evident in the scar implantation sites. Conclusions:This study emphasizes that the decidua drives multinucleated trophoblast giant cell differentiation, limiting the degree of invasion. Better characterization of this differentiation process may be helpful for better management and avoidance of the consequences of cesarean scar pregnancy.

The value of ultrasound parameters in predicting the efficacy of transabdominal ultrasound‐guided suction curettage alone in the treatment of cesarean scar pregnancy

“…Our study confirmed this hypothesis by indicating that chorionic villus thickness at the scar is a significant risk factor for failure of TAUS‐guided suction curettage alone of CSP; when the chorionic villus thickness at the scar exceeds 4.7 mm, the likelihood of failure increases by 15‐fold. This phenomenon may be attributed to the invasive nature of chorionic cells during early pregnancy, which preferentially adhere to and invade the scar area compared with the metaplastic area 25,26 . The aforementioned observation implies that the thickness of the chorionic villi at the scar may serve as an indicator of the extent of villi invasion, whereby a thicker chorionic villi layer corresponds to a higher degree of invasion and a greater probability of unsuccessful TAUS‐guided suction curettage.…”

Animal models of the placenta accreta spectrum: current status and further perspectives

“…The process of uterine tissue repair after CS is often accompanied by decreasing endometrial glands, inhibition of myometrial smooth muscle cell growth, excessive collagen fiber deposition, and massive leukocyte infiltration, which leads to long-term and chronic inflammation and scarring ( 63 ). There appears to be preferential attachment of the blastocyst to the scar site, which may be associated with defective decidua in that region, resulting in abnormal implantation ( 64 ). In turn, disorientation of the implanted embryo and restricted stromal cell proliferation could also lead to defective decidualization and abnormal placental development, including excessive invasion of trophoblasts into the decidua and insufficient branching of fetal blood vessels ( 65 , 66 ).…”

“…However, the mechanism and signaling pathway of how myometrial injury affects EVT invasion and placental development is rarely reported. Only a few studies have reported that EVT migration and invasion into the myometrium may be related to the downregulation of functional E-cadherin in the myometrium of uterine scars ( 64 ). This model is very suitable for research on the pathomechanism of PAS in the aspect of impaired myometrium.…”

Appendiceal perforation secondary to endometriosis with intestinal metaplasia: A case report

“…Serial sections (4 µm) were also prepared for Masson's trichrome (Masson), Alcian blue-periodic acid Schiff (AB-PAS) and immunohistochemistry staining. Masson and immunohistochemistry staining were performed according to the protocols established in Department of Pathology, Jinan University School of Medicine previously ( 6 ). The following primary antibodies were used: cluster of differentiation (CD)10 (cat.…”