Effect of Mediterranean diet or mindfulness-based stress reduction during pregnancy on placental volume and perfusion: A subanalysis of the IMPACT BCN randomized clinical trial.

INTRODUCTION: The IMPACT BCN trial-a parallel-group randomized clinical trial where 1221 pregnant women at high risk for small-for-gestational age (SGA) newborns were randomly allocated at 19- to 23-week gestation into three groups: Mediterranean diet, Mindfulness-based Stress reduction or non-intervention-has demonstrated a positive effect of Mediterranean diet and Stress reduction in the prevention of SGA. However, the mechanism of action of these interventions remains still unclear. The aim of this study is to investigate the effect of Mediterranean diet and Stress reduction on placental volume and perfusion. MATERIAL AND METHODS: Participants in the Mediterranean diet group received monthly individual and group educational sessions, and free provision of extra-virgin olive oil and walnuts. Women in the Stress reduction group underwent an 8-week Stress reduction program adapted for pregnancy, consisting of weekly 2.5-h and one full-day sessions. Non-intervention group was based on usual care. Placental volume and perfusion were assessed in a subgroup of randomly selected women (n = 165) using magnetic resonance (MR) at 36-week gestation. Small placental volume was defined as MR estimated volume <10th centile. Perfusion was assessed by intravoxel incoherent motion. RESULTS: While mean MR placental volume was similar among the study groups, both interventions were associated with a lower prevalence of small placental volume (3.9% Mediterranean diet and 5% stress reduction vs. 17% non-intervention; p = 0.03 and p = 0.04, respectively). Logistic regression showed that small placental volume was significantly associated with higher risk of SGA in both study groups (OR 7.48 [1.99-28.09] in Mediterranean diet and 20.44 [5.13-81.4] in Stress reduction). Mediation analysis showed that the effect of Mediterranean diet on SGA can be decomposed by a direct effect and an indirect effect (56.6%) mediated by a small placental volume. Similarly, the effect of Stress reduction on SGA is partially mediated (45.3%) by a small placental volume. Results on placental intravoxel incoherent motion perfusion fraction and diffusion coefficient were similar among the study groups. CONCLUSIONS: Structured interventions during pregnancy based on Mediterranean diet or Stress reduction are associated with a lower proportion of small placentas, which is consistent with the previously observed beneficial effects of these interventions on fetal growth.

Oral administration of Bifidobacterium longum ES1 reduces endometrial inflammation in women with recurrent pregnancy loss.

BACKGROUND: Over-activation of endometrial inflammasome NALP-3 (Nod-like receptor family pyrin domain containing 3) can be found in recurrent pregnancy loss (RPL) women probably due to leaky gut and passage into circulation of lipopolysaccharides (LPS). Leaky gut can be caused by exposure to gluten in RPL women genetically predisposed to celiac disease, positive for Human Leukocyte Antigen (HLA)-DQ2/DQ8 haplotype. Oral administration of Bifidobacterium longum ES1 (GliadinES®) can inactivate gluten peptides toxicity to epithelial gut cells and improve gut barrier. METHODS: We investigated by enzyme-linked immunoassay: (a) serum levels of LPS and zonuline (a marker of leaky gut); (b) LPS, NALP-3, caspase-1, interleukine (IL)-1ß and IL-18 concentration in endometrial fluids, in untreated women with uncomplicated pregnancies (negative HLA-DQ2/DQ8 haplotype) (n = 22) and in women with unexplained RPL, HLA-DQ2/DQ8 positive (n = 22), before and after daily oral administration for 3 months of GliadinES®. RESULTS: RLP women showed higher serum levels of LPS (p < 0.0001) and higher concentration of LPS (p < 0.0001), NALP-3 (p < 0.01); Caspase-1 (p < 0.0001), IL-1ß (p < 0.0001), and IL-18 (p < 0.0001) in endometrial fluids compared to controls. GliadinES® treatment significantly reduced serum levels of both LPS (p < 0.0001) and zonuline (p < 0.01), as well as LPS (p < 0.5), NALP-3 (p < 0.01), Caspase-1 (p < 0.001), IL-1ß (p < 0.001), and IL-18 (p < 0.01) concentrations in endometrial fluids of RPL women. CONCLUSIONS: RPL women positive for HLA-DQ2/DQ8 haplotype show increased circulating and endometrial levels of LPS and endometrial inflammasome NALP-3 over-activation. Oral administration of GliadinES® can reduce gut permeability, decrease serum levels of LPS and, contextually, improve endometrial inflammation in this specific subset of RPL women.

Cardiac remodeling from the fetus to adulthood.

Prenatal cardiac remodeling refers to in utero changes in the fetal heart that occur as a response to an adverse intrauterine environment. In this article, we will review the main mechanisms leading to cardiac remodeling and dysfunction, summarizing and describing the major pathological conditions that have been reported to be related to this in utero plastic adaptive process. We will also recap the current evidence regarding the persistence of fetal cardiac remodeling and dysfunction, both in infancy and later in adult life. Moreover, we will discuss primary, secondary, and tertiary preventive measures and future clinical and research aspects.

Celiac Disease Predisposition and Genital Tract Microbiota in Women Affected by Recurrent Pregnancy Loss.

The incidence of Idiopathic Recurrent Pregnancy Loss (RPL) is doubled in patients suffering from Celiac Disease (CD) compared to healthy populations. CD genetic components are HLA class II genes known as HLA-DQ2 and DQ8. Genetically susceptible women can remain asymptomatic even though they are exposed to a doubled risk of RPL compared to the general population. Furthermore, CD has been associated with microbiota alterations. The aim of this study is to evaluate endometrial and vaginal microbiota in HLA-DQ2/DQ8 positive and negative RPL patients compared to healthy pregnant women. Endometrial and vaginal microbiota of 3 subgroups were evaluated: 15 HLA-DQ2/DQ8 positive RPL women, 25 HLA DQ2/DQ8 negative RPL women (for a total of 40 RPL women) and 7 healthy fertile controls with previous uncomplicated pregnancies (all HLA-DQ2/DQ8 negative). The 2 RPL subgroups (HLA-DQ2/DQ8 positive and negative) showed a different endometrial and vaginal composition in the Lactobacillacae family compared to controls: Lactobacillus acidophilus was absent both in the vaginal and endometrial samples of RPL women, while Lactobaciluus iners, which can favor a less stable vaginal microbiota, was found only in RPL women (26.4% in HLA DQ2/DQ8 positive and 22.1% HLA DQ2/DQ8 negative) in both the vaginal and endometrial districts. In conclusion, both HLA DQ2/DQ8 positive-RPL and HLA DQ2/DQ8 negative-RPL women showed different endometrial and vaginal microbiota composition compared to healthy controls.

Enoxaparin Increases D6 Receptor Expression and Restores Cytoskeleton Organization in Trophoblast Cells from Preeclampsia.

D6 is a scavenger receptor for CC chemokines expressed in the human placenta. It prevents excessive leukocyte tissue infiltration by internalizing chemokines through cytoskeleton-dependent intracellular transport. In preeclampsia (PE), the D6 receptor is overexpressed in trophoblast cells, but functionally impaired, due to cytoskeleton destructuring. Low molecular weight heparin (LMWH) represents a potential treatment for PE based on its anti-thrombotic and anti-inflammatory properties. Here, we investigated the effect of enoxaparin on D6 expression, and cytoskeleton organization primary cytotrophoblast cell cultures were obtained from the placentae of women with PE (n = 9) or uncomplicated pregnancy (n = 9). We demonstrated that enoxaparin is able to (i) increase D6 expression, and (ii) improve cytoskeletal fiber alignment in trophoblast cells from PE patients.

α-Lipoic Acid and its Role on Female Reproduction.

α-lipoic Acid (ALA), also known as thioctic acid, is a biological thiol present in all types of prokaryotic and eukaryotic cells. It has been shown that ALA or its reduced form, DHLA, has several positive effects on human health, acting as a biological antioxidant, metal chelator and detoxifying agent. It is able to reduce the oxidation of several antioxidant agents like glutathione, vitamins C and E, and modulate insulin and NF-kB signaling pathways. ALA's pharmacological effects are not only related to its antioxidant properties but it shows an anti-inflammatory action. In particular, ALA is able to reduce inflammasome activity, the pro-inflammatory cytokine levels, such as TNF-α, IL-1ß, IL-6, IL-18 and IL-17, interferon (INF)-γ as well as the production of Vascular and Intercellular cell adhesion protein (VCAM-1 and ICAM-1). In recent papers, ALA has been indicated as a possible therapeutic approach to several endocrine or inflammatory disorders affecting female reproduction. Aim of the current review was to assess whether ALA has an evidence- based beneficial role on gynecological and obstetrical diseases such as polycystic ovary syndrome (PCOS), endometriosis, and miscarriage.

Alpha-Lipoic Acid Plays a Role in Endometriosis: New Evidence on Inflammasome-Mediated Interleukin Production, Cellular Adhesion and Invasion.

Endometriosis is an estrogen-linked gynecological disease defined by the presence of endometrial tissue on extrauterine sites where it forms invasive lesions. Alterations in estrogen-mediated cellular signaling seems to have an essential role in the pathogenesis of endometriosis. Higher estrogen receptor (ER)-ß levels and enhanced ER-ß activity were detected in endometriotic tissues. It is well known that ER-ß interacts with components of the cytoplasmic inflammasome-3 (NALP-3), the NALP-3 activation increases interleukin (IL)-1ß and IL-18, enhancing cellular adhesion and proliferation. Otherwise, the inhibition of ER-ß activity suppresses the ectopic lesions growth. The present study aims to investigate the potential effect of α-lipoic acid (ALA) on NALP-3 and ER-ß expression using a western blot analysis, NALP-3-induced cytokines production by ELISA, migration and invasion of immortalized epithelial (12Z) and stromal endometriotic cells (22B) using a 3D culture invasion assay, and matrix-metalloprotease (MMPs) activity using gelatin zymography. ALA significantly reduces ER-ß, NALP-3 protein expression/activity and the secretion of IL-1ß and IL-18 in both 12Z and 22B cells. ALA treatment reduces cellular adhesion and invasion via a lower expression of adhesion molecules and MMPs activities. These results provide convincing evidence that ALA might inhibit endometriosis progression.

Celiac disease and reproductive failures: An update on pathogenic mechanisms.

Celiac disease (CD) is an autoimmune disorder that occurs in genetically predisposed people in which the ingestion of gluten leads to damage in the small intestine that clinically presents with malabsorption-related symptoms. CD can also be the underlying cause of several non-gastrointestinal symptoms. This review summarizes evidence on the relationship between CD and gynecological/obstetric disorders like reproductive failures. Although much has been reported on such a linkage, the pathogenic mechanisms remain unclear, especially those underlying extra-gastrointestinal clinical manifestations. Studies conducted on celiac subjects presenting gynecological/obstetric disorders have pointed to intestinal malabsorption, coagulation alterations, immune-mediated tissue damage, and endometrial inflammation as the main responsible pathogenic mechanisms. Currently, however, the knowledge of such mechanisms is insufficient, and further studies are needed to gain a more thorough understanding of the matter.

SARS-CoV2 vertical transmission with adverse effects on the newborn revealed through integrated immunohistochemical, electron microscopy and molecular analyses of Placenta.

BACKGROUND: . The occurrence of trans-placental transmission of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection remains highly debated. Placental positivity for SARS-CoV-2 has been reported in selected cases, but infection or virus-associated disease of fetal tissues or newborns remains to be demonstrated. METHODS: We screened for SARS-CoV-2 spike (S) protein expression placentas from 101 women who delivered between February 7 and May 15, 2020, including 15 tested positive for SARS-CoV-2 RNA, 34 tested negative, and 52 not evaluated as they did not meet testing criteria (32), or delivered before COVID-19 pandemic declaration (20). Immunostain for SARS-CoV-2 nucleocapsid (N) was performed in the placentas of all COVID-19 positive women. One placenta resulted positive for the SARS-CoV-2 S and N proteins, which was further studied by RNA-in situ hybridization and RT-PCR for S transcripts, and by electron microscopy. A comprehensive immunohistochemical and immunofluorescence analysis of the placental inflammatory infiltrate completed the investigations. FINDINGS: SARS-CoV-2 S and N proteins were strongly expressed in the placenta of a COVID-19 pregnant woman whose newborn tested positive for viral RNA and developed COVID-19 pneumonia soon after birth. SARS-CoV-2 antigens, RNA and/or particles morphologically consistent with coronavirus were identified in villous syncytiotrophoblast, endothelial cells, fibroblasts, in maternal macrophages, and in Hofbauer cells and fetal intravascular mononuclear cells. The placenta intervillous inflammatory infiltrate consisted of neutrophils and monocyte-macrophages expressing activation markers. Absence of villitis was associated with an increase in the number of Hofbauer cells, which expressed PD-L1. Scattered neutrophil extracellular traps (NETs) were identified by immunofluorescence. INTERPRETATION: We provide first-time evidence for maternal-fetal transmission of SARS-CoV-2, likely propagated by circulating virus-infected fetal mononuclear cells. Placenta infection was associated with recruitment of maternal inflammatory cells in the intervillous space, without villitis. PD-L1 expression in syncytiotrophoblast and Hofbaeur cells, together with limited production of NETs, may have prevented immune cell-driven placental damage, ensuring sufficient maternal-fetus nutrient exchanges.

Expression of Pinopodes in the Endometrium from Recurrent Pregnancy Loss Women. Role of Thrombomodulin and Ezrin.

BACKGROUND: Pinopode expression has been suggested as a marker of endometrial receptivity. METHODS: We set up an experimental study comparing endometrial tissue from recurrent pregnancy loss (RPL, n = 30) and fertile control (CTR, n = 20) women in terms of pinopode expression/morphology; expression of thrombomodulin (TM) and ezrin; cytoskeletal organization. Endometrial samples were collected during implantation window and evaluated by scanning electron microscopy, western blot, and immunofluorescence. RESULTS: We found that RPL endometrial tissue showed: (i) increased pinopodes density (* p < 0.05); (ii) a reduced diameter of pinopodes (* p < 0.05); (iii) a decreased TM and ezrin expression (p < 0.05). Additionally, confocal images showed a significantly reduced expression of phosphorylated (p)-ezrin, confirming the results obtained through immunoblot analysis. Immunofluorescence staining showed that in CTR samples, junctions between cells are intact and clearly visible, whereas actin filaments appear completely lost in RPL endometrial samples; this suggests that, due to the impaired expression and activity of TM and ezrin, actin does not bind to plasma membrane in order to orchestrate the cytoskeletal actin filaments. CONCLUSIONS: Our findings suggest that an impaired expression of TM and expression/activation of ezrin may affect the connection between the TM and actin cytoskeleton, impairing the organization of cytoskeleton and, eventually, the adequate pinopode development.

Synthetic PreImplantation Factor (sPIF) reduces inflammation and prevents preterm birth.

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality and spontaneous PTB is a major contributor. The preceding inflammation/infection contributes not only to spontaneous PTB but is associated with neonatal morbidities including impaired brain development. Therefore, control of exaggerated immune response during pregnancy is an attractive strategy. A potential candidate is synthetic PreImplantation Factor (sPIF) as sPIF prevents inflammatory induced fetal loss and has neuroprotective properties. Here, we tested maternal sPIF prophylaxis in pregnant mice subjected to a lipopolysaccharides (LPS) insult, which results in PTB. Additionally, we evaluated sPIF effects in placental and microglial cell lines. Maternal sPIF application reduced the LPS induced PTB rate significantly. Consequently, sPIF reduced microglial activation (Iba-1 positive cells) and preserved neuronal migration (Cux-2 positive cells) in fetal brains. In fetal brain lysates sPIF decreased IL-6 and INFγ concentrations. In-vitro, sPIF reduced Iba1 and TNFα expression in microglial cells and reduced the expression of pro-apoptotic (Bad and Bax) and inflammatory (IL-6 and NLRP4) genes in placental cell lines. Together, maternal sPIF prophylaxis prevents PTB in part by controlling exaggerated immune response. Given the sPIF`FDA Fast Track approval in non-pregnant subjects, we envision sPIF therapy in pregnancy.

Effect of alpha-lipoic acid and myoinositol on endometrial inflammasome from recurrent pregnancy loss women.

PROBLEM: A significant increased expression/activation of one of the most well-characterized inflammasomes, the NAcht leucine-rich-repeat protein-3 (NALP-3), in the endometrium from idiopathic recurrent pregnancy loss women (RPL) has been previously found by our research group. We therefore, suggested this event as being one of the molecular mechanisms altering endometrial inflammatory status during early pregnancy. In the present research, we attempt to investigate whether molecules with anti-inflammatory activity, alpha-lipoic acid (ALA), and/or myoinositol affect the endometrial NALP-3 expression and activation. METHOD OF STUDY: Women with a history of idiopathic RPL (n = 30) were included in the study and compared to a control group (n = 15). Endometrial tissues were collected by hysteroscopy during the mid-luteal phase. RPL women underwent a three-month prescription of tablets containing ALA plus myoinositol (Sinopol® ). After treatment, hysteroscopic biopsies were repeated in RPL patients. Inflammasome expression was evaluated by immunohistochemical and Western blot analysis. NALP-3 activation was studied by quantifying the secretion of both caspase-1 and interleukin (IL)-1ß and IL-18 through ELISA. In ex vivo experiments, the effects of each molecule on endometrial inflammasome were studied. RESULTS: Sinopol® significantly reduced the RPL endometrial inflammasome expression and activation. ALA, but not myoinositol, significantly reduced the endometrial inflammasome expression and activity. CONCLUSION: Our data suggest a role for ALA on RPL inflammasome. Understanding the mechanisms involved in RPL and the observation that specific molecules are able to interfere with such complex at the endometrium might provide new rational design approaches to a personalized evaluation of endometrial status and, ultimately, a targeted medicine.

Synthetic PreImplantation Factor (PIF) prevents fetal loss by modulating LPS induced inflammatory response.

Maternal control of inflammation is essential during pregnancy and an exaggerated response is one of the underlying causes of fetal loss. Inflammatory response is mediated by multiple factors and Toll-like receptors (TLRs) are central. Activation of TLRs results in NALP-3 mediated assembly of apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 into the inflammasome and production of pro-inflammatory cytokines IL-1ß and IL-18. Given that preventing measures are lacking, we investigated PreImplantation Factor (PIF) as therapeutic option as PIF modulates Inflammation in pregnancy. Additionally, synthetic PIF (PIF analog) protects against multiple immune disorders. We used a LPS induced murine model of fetal loss and synthetic PIF reduced this fetal loss and increased the embryo weight significantly. We detected increased PIF expression in the placentae after LPS insult. The LPS induced serum and placenta cytokines were abolished by synthetic PIF treatment and importantly synthetic PIF modulated key members of inflammasome complex NALP-3, ASC, and caspase-1 as well. In conclusion our results indicate that synthetic PIF protects against LPS induced fetal loss, likely through modulation of inflammatory response especially the inflammasome complex. Given that synthetic PIF is currently tested in autoimmune diseases of non-pregnant subjects (clinicaltrials.gov, NCT02239562), therapeutic approach during pregnancy can be envisioned.

The chromosome analysis of the miscarriage tissue. Miscarried embryo/fetal crown rump length (CRL) measurement: A practical use.

OBJECTIVE: To investigate whether miscarried embryo/fetal crown rump length (CRL) measurement may yield a practical application for predicting a conclusive result at the cytogenetic analysis of miscarriage tissue. Our study might help in improving the cytogenetic method, the results of which may be affected by maternal cell contamination (MCC). In particular, we aimed at establishing whether the miscarried embryo/fetal CRL measurement shows accuracy in predicting the possibility of MCC and the scan cut-off value useful to this purpose and, as a result, suggest a multi-step procedure for the genetic ascertainment. METHODS: Women experiencing at least two miscarriages of less than 20 weeks size at the Pregnancy Loss Unit at Fondazione Policlinico A. Gemelli underwent a scan before surgery. The CRL value was recorded. After the dilatation and courettage (D&C) procedure, miscarriage tissue was processed through the proposed multi-step procedure before performing oligo-nucleotide-based and SNP (single nucleotide polymorphisms)-based comparative genomic hybridization (CGH+SNP) microarray analysis. RESULTS: 63 women and 63 miscarriages met the criteria. By using the Receiving Operator Characteristic (ROC) curves, CRL showed an AUC of 0.816 (95%CI:0.703-0.928,p<0.001). A CRL≥24.5 mm cut-off value showed a higher positive likelihood ratio (5.27) but, conversely, a higher negative likelihood ratio (0.64) in predicting the possibility of MCC. Microarray analysis was successful in the totality of cases in which the embryo/fetal origin of miscarriage tissues was proven. CONCLUSIONS: The 24.5 mm CRL value emerges as the most suitable cut-off enabling the identification of cases in which the embryo-fetal component can be isolated in the absence of MCC and the chromosomal array provide informative results.

Helicobacter pylori infection contributes to placental impairment in preeclampsia: basic and clinical evidences.

BACKGROUND: Preeclampsia (PE) is a major cause of maternal and neonatal morbidity and mortality. Epidemiological association between Helicobacter pylori (Hp) infection and PE onset has been widely shown. The aim of this study was to analyze a possible correlation between Hp infection and the severity of clinical presentation of PE and to identify an immunologic mechanism triggered by Hp infection potentially contributing to the pathogenesis of PE. MATERIALS AND METHODS: Sera from 93 preeclamptic women and 87 healthy pregnant women were tested for Hp infection by immunoassay and for anti-CagA antibodies by Western blot assay. The serologic results were correlated with the clinical features of PE. The functional effect of serum IgG fractions, positive or negative for Hp, from preeclamptic women or controls were tested on trophoblast and endothelial cell cultures and in a murine model of angiogenesis. RESULTS: Preeclamptic women showed higher seroprevalence of Hp infection (57.0%) compared to controls (33.3%) (P<.001). The seropositivity for CagA-positive strains of Hp was 45.2% in preeclamptic women vs 13.7% in controls (P<.001). In PE women, Hp infection was associated with abnormality of uterine arteries Doppler (P<.001). Hp+ IgG fractions from preeclamptic women bound to trophoblast and endometrial endothelial cell cultures, reducing in vitro invasiveness and angiogenesis, respectively, and inhibited angiogenesis in mice. CONCLUSIONS: Our data show, for the first time, an association between Hp infection and PE with abnormal uterine arteries Doppler velocimetry, suggesting a role for Hp infection in impairing placental development and increasing the risk to develop PE. This study opens the new perspective of a potential screening and treatment for Hp infection in pregnancy.

Human leukocyte antigen (HLA) DQ2/DQ8 prevalence in recurrent pregnancy loss women.

OBJECTIVE: Over the last few years, medical scholars have reported the significant association between recurrent pregnancy loss (RPL) and celiac disease (CD). Various pathogenic mechanisms underlying the pregnancy failure in CD have been suggested: among them the ability of anti-transglutaminase antibodies to impair the trophoblast invasiveness and endometrial endothelial cells differentiation and disrupt early placentation. CD shows a complex non-Mendelian pattern of inheritance, involving major histocompatibility complex (MHC) genes. The strongest effects are mapped to the classical human leukocyte antigen (HLA)-DQA1 and HLA-DQB1 genes. Specifically, the common haplotypes DQ2.5, DQ2.2, and DQ8 have been shown to increase CD risk by six-fold on average. MHC region contains genes with immunological functions and is responsible for the strongest association signals observed in most immune-mediated diseases. The aim of our study was to investigate the prevalence of the HLA-DQ2/DQ8 haplotypes in RPL, outside of CD. METHODS: The study population included women with history of RPL (≥3 spontaneous pregnancy losses) and women with at least two previous uncomplicated term pregnancies (control group, CTR). All women gave their informed consent to use their data for research purposes. RESULTS: 97 RPL women and 55 CTR were considered in the study. Mean age of the RPL sample was 37.7 (standard deviation, SD, 3.0; min 27; max 39). Mean age of the control group was 35.6 (SD 3.0; min 26years; m, max 38). A significantly increased prevalence of HLA-DQ2/DQ8 haplotype positivity was found in RPL population compared to control women (52.6% vs 23.6%; p<0.01). CONCLUSIONS: Our observations show for the first time a higher proportion of individuals HLA DQ2/DQ8 positive in women with RPL as compared to controls (and to general population estimates). Further studies are needed to better understand (i) the possible pathogenic mechanism to this observation; (ii) the clinical and therapeutic implications of our observation in order to provide a new approach to RPL couples.

Inflammosome in the human endometrium: further step in the evaluation of the "maternal side".

OBJECTIVE: To investigate the expression of inflammosome components (NALP-3, associated speck-like protein containing a CARD [ASC]) and their activation (caspase-1, interleukin [IL]-1ß, and IL-18 secretion) in the human endometrium from fertile and women with history of recurrent pregnancy loss (RPL). DESIGN: Experimental study. SETTING: University hospital. PATIENT(S): Ten fertile women (control group [CTR]) and 30 women with RPL. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Endometrial samples were collected by hysteroscopy during the putative window of implantation and evaluated for chronic endometrial inflammation by hystopathological analysis. Inflammosome expression was analysed by immunohystochemical staining (27 RPL and 10 CTR women). The expression of NALP-3 and ASC protein was quantified by Western blot (30 RPL and 10 CTR women). Caspase-1 activation and IL-1ß and IL-18 secretion was quantified by ELISA (30 RPL and 10 CTR women). RESULT(S): We observed a significantly increased expression of inflammasome NALP-3 and ASC protein, an increased activation of caspase-1, and increased levels of IL-1ß and IL-18 in RPL endometrium compared with CTR. CONCLUSION(S): Abnormal activation of endometrial innate immunity by means of inflammosome, stimulated by pathogen- or damage-associated molecular patterns, may represent an additional mechanism, currently not investigated, negatively interfering with endometrial receptivity. More studies are required [1] to identify the primary trigger of endometrial inflammosome activation and its clinical impact in the occurrence of RPL; and [2] to validate the inflammosome components as a novel family of endometrial biomarkers and promising therapeutic targets in RPL.