Extravillous trophoblast invasion and decidualization in cesarean scar pregnancies.

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.

Alterted SLIT2/ROBO1 signalling is linked to impaired placentation of missed and threatened miscarriage in early pregnancy.

AIMS: Two-thirds of early pregnancy failures present with reduced trophoblast invasion, and SLIT2/ROBO1 signalling is considered to play an important role in trophoblast function during pregnancy. We investigated SLIT2/ROBO1 signalling associated with missed and threatened miscarriage during early gestation. METHODS AND RESULTS: Human placenta samples were collected from women with missed miscarriage (n = 25), threatened miscarriage (n = 22) and termination of pregnancy controls (n = 32). Corresponding decreases in beta human chorionic gonadotrophin (ß-hCG) levels and shallow trophoblast invasion were observed in patients with missed and threatened miscarriage, immunohistological staining revealed abnormal Slit2 and Robo1, as well as E-cadherin and activating protein-2 alpha (AP-2α) expression in villi and extravillous trophoblasts, and the expression of these proteins were confirmed in villi and decidua of miscarriage material by Western blotting. Using HTR8/SVneo cells, blocking SLIT2/ROBO1 signalling promoted cell migration, proliferation and suppressed differentiation. Moreover, blocking SLIT2/ROBO1 signalling in HTR8/SVneo cells altered trophoblast differentiation-related and angiogenesis-related gene mRNA expression, which also occurred in the tissues of missed and threatened miscarriage. CONCLUSIONS: SLIT2/ROBO1 signalling may regulate trophoblast differentiation and invasion causing restricting ß-hCG production, shallow trophoblast invasion and inhibiting placental angiogenesis in missed and threatened miscarriage during the first trimester.

Role of Slit2 upregulation in recurrent miscarriage through regulation of stromal decidualization.

INTRODUCTION: Knockout mouse model has shown a relationship between Slit2/Robo1 signalling and altered fertility. Altered expression by endometrial epithelium and trophoblast and is associated with the pathogenesis of pregnancy complications but few studies have investigated the expression of decidual Slit2 in miscarriage. METHODS: Expression profiles of Slit2 and Robo1 were measured in human endometrial tissues during the menstrual cycle phases (n = 30), in decidua tissues from recurrent miscarriage (n = 20) and healthy control (n = 20) at 6-8 weeks of gestation. The hormonal regulation of Slit2/Robo1 expression and the role of Slit2/Robo1 signalling in decidualization was investigated in vitro, along with its effects on ß-catenin and MET expression. RESULTS: In human endometrium, Slit2 and Robo1 protein expression in stromal cells were decreased between the late-proliferative and early-secretory phase. In recurrent miscarriage patients, decidual expression Slit2 was increased and associated with lower expression of E-cadherin and higher level vimentin compared to controls. In vitro, the expression of Slit2 was downregulated by cAMP and progesterone in hESCs. Upregulation of Slit2 resulted in inhibition of cell decidualization and ß-catenin translocation to nucleus. DISCUSSION: This study indicates a functional role for Slit2 in endometrial stromal cell decidualization and the pathogenesis of recurrent miscarriage. Aberrant Increase in Slit2 expression may impairs decidualization of endometrial stromal cells leading to recurrent in recurrent miscarriage.

Bone Marrow Mesenchymal Stem Cells (BMSCs) Restore Functional Endometrium in the Rat Model for Severe Asherman Syndrome.

OBJECTIVE: To investigate the feasibility to restore functional endometrium using bone marrow mesenchymal stem cells (BMSCs) in the Sprague Dawley (SD["SD" has been defined as both "Sprague Dawley" and "standard deviation." Please clarify which one is to be followed.]) rat model for Asherman syndrome (AS). DESIGN: Basic research on treatment of AS utilizing an optimized rat model. SETTING: University research laboratories. ANIMAL(S): Sprague Dawley rat model in which AS was induced in accordance to an optimized protocol. INTERVENTION(S): Bone marrow mesenchymal stem cells were harvested from the rat's bone marrow and labeled with green fluorescent protein (GFP) in the second passage of BMSCs. The fifth passage of GFP-labeled BMSCs was injected systemically through the tail vein in the optimized AS rat model. MAIN OUTCOME MEASURE(S): We examined the reproliferation of the endometrial lining and the expression of markers for endometrium and endometrial receptivity. The localization of engrafted GFP-labeled BMSCs was determined by a laser scanning confocal microscope and a fluorescence microscope. The number of pregnant rats and implanted embryos in each uterus was recorded to evaluate the function of endometrium. RESULT(S): We had demonstrated that in the in vivo experiments on our rat model for AS, the group which received BMSC injection had significantly improved reproductive outcomes-70% of these rats conceived, whereas none of the rats in the control group got pregnant ( P < .01, χ2 test). The mean number of embryos undergoing implantation was 14 ± 1.24 in the sham group and 7 ± 5.70 in the BMSC group (Levene test, P = .001). There was no significant difference between the groups from the time of coitus to conception. To further determine how BMSC injection could have resulted in the improved reproductive outcomes in rats with AS, we employed immunohistochemical techniques to examine the endometrium of these treated rats. On hematoxylin-eosin staining, we noted the reproliferation of all layers of the endometrium and with Masson staining, we noted significant reduction in fibrosis in the damaged endometrium of rats treated with BMSCs. Counterstaining for GFP and cytokeratin-positive cells was noted in the endometrial lining of treated rats, which might suggest the action of BMSCs in regenerating the damaged endometrial lining. The expression of the endometrial receptivity marker, Leukemia inhibitory factor (LIF), in this regenerated endometrial lining could have resulted in the improved reproductive outcomes observed in the AS rat model treated with BMSCs. CONCLUSION: Bone marrow mesenchymal stem cells were likely to play an important role in the reconstruction of the injured endometrium and improvement of reproductive outcomes in the optimized AS rat model.

Reproductive outcomes following cesarean scar pregnancy - a case series and review of the literature.

OBJECTIVE: To assess the reproductive outcomes following cesarean scar pregnancy (CSP) in our center and review of published literature on CSP and subsequent reproductive issues. METHODS: Over a 3-year period, 28 cases of CSPs were diagnosed in our hospital. Follow up data of 22 cases were available which included the gestational age at diagnosis of CSP, treatments employed and outcomes of previous cesarean scar pregnancy. We also had details on subsequent fertility outcomes in these women, which included intervals between the previous CSP and subsequent pregnancy, maternal and neonatal outcomes of these subsequent pregnancies and mode of delivery. RESULTS: Eight women desired to conceive and amongst them, seven women manage to conceive spontaneously. There were five pregnancies delivered at term, two miscarriages and one recurrent CSP. One patient had placenta accreta diagnosed at cesarean section at term and had massive hemorrhage. The remaining 4 term pregnancies were delivered uneventfully by elective cesarean sections. The mean interval between the cesarean scar pregnancy and subsequent pregnancy was 24.6 months (range 9-48 months). One patient experienced secondary infertility and despite thorough investigations, no abnormalities were detected. One of the women who did not desire future fertility conceived spontaneously at 9 and 18 months respectively after one CSP and had induced abortions twice. There were 3 women who had uterine scar defect repaired, only 1 resulted in a live birth but had placenta accreta with a lower uterine segment defect and suffered from massive hemorrhage, one woman had a subsequent miscarriage with a diverticulum in the lower uterine segment, and one woman had unexplained secondary infertility. CONCLUSION: Most women were able to conceive following CSPs. Reproductive outcomes included normal intrauterine term pregnancy, miscarriage, recurrent CSP, and infertility. Placenta accreta, which could be misdiagnosed antenatally, was a serious complication in subsequent pregnancies. Diverticulum or defect in the lower uterine segment could happen after CSP. Repair of the uterine defect, following a CSP neither guaranteed the healing of the scar, nor the ability to ensure a safe pregnancy outcome. Appropriate counseling to women desiring fertility with a history of CSP is essential and once they conceive early referral to tertiary centers for follow up is pertinent.