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B cells constitute a diverse and adaptable immune cell population with functions that can vary according to the environment and circumstances. The involvement of B cells in pregnancy, as well as the associated molecular pathways, has yet to be investigated. This review consolidates current knowledge on B cell activities and regulation during pregnancy, with a particular focus on the roles of various B cell subsets and the effects of B cell-derived factors on pregnancy outcomes. Moreover, the review examines the significance of B cell-associated autoantibodies, cytokines, and signaling pathways in relation to pregnancy complications such as pregnancy loss, preeclampsia, and preterm birth. [ABSTRACT FROM AUTHOR]

Background: At menstruation, the functional layer of the human endometrium sheds off due to the trigger of the release of inflammatory factors, including interleukin 6 (IL-6), as a result of a sharp decline in progesterone levels, leading to tissue breakdown and bleeding. The endometrial mesenchymal stem-like cells (CD140b+CD146+ eMSC) located in the basalis are responsible for the cyclical regeneration of the endometrium after menstruation. Endometrial cells from the menstruation phase have been proven to secrete a higher amount of IL-6 and further enhance the self-renewal and clonogenic activity of eMSC. However, the IL-6-responsive mechanism remains unknown. Thus, we hypothesized that IL-6 secreted from niche cells during menstruation regulates the proliferation and self-renewal of eMSC through the WNT/b-catenin signaling pathway. Methods: In this study, the content of IL-6 across the menstrual phases was first evaluated. Coexpression of stem cell markers (CD140b and CD146) with interleukin 6 receptor (IL-6R) was confirmed by immunofluorescent staining. In vitro functional assays were conducted to investigate the effect of IL-6 on the cell activities of eMSC, and the therapeutic role of these IL-6- and WNT5A-pretreated eMSC on the repair of injured endometrium was observed using an established mouse model. Results: The endometrial cells secrete a high amount of IL-6 under hypoxic conditions, which mimic the physiological microenvironment in the menstruation phase. Also, the expression of IL-6 receptors was confirmed in our eMSC, indicating their capacity to respond to IL-6 in the microenvironment. Exogenous IL-6 can significantly enhance the self-renewal, proliferation, and migrating capacity of eMSC. Activation of the WNT/b-catenin signaling pathway was observed upon IL-6 treatment, while suppression of the WNT/b-catenin signaling impaired the stimulatory role of IL-6 on eMSC activities. IL-6- and WNT5A-pretreated eMSC showed better performance during the regeneration of the injured mouse endometrium. Conclusion: We demonstrate that the high level of IL-6 produced by endometrial cells at menstruation can induce the stem cells in the human endometrium to proliferate and migrate through the activation of the WNT/b-catenin pathway. Treatment of eMSC with IL-6 and WNT5A might enhance their therapeutic potential in the regeneration of injured endometrium. [ABSTRACT FROM AUTHOR]

BACKGROUND The establishment of maternal–fetal crosstalk is vital to a successful pregnancy. Glycosylation is a post-translational modification in which glycans (monosaccharide chains) are attached to an organic molecule. Glycans are involved in many physiological and pathological processes. Human endometrial epithelium, endometrial gland secretions, decidual immune cells, and trophoblasts are highly enriched with glycoconjugates and glycan-binding molecules important for a healthy pregnancy. Aberrant glycosylation in the placenta and uterus has been linked to repeated implantation failure and various pregnancy complications, but there is no recent review summarizing the functional roles of glycosylation at the maternal–fetal interface and their associations with pathological processes. OBJECTIVE AND RATIONALE This review aims to summarize recent findings on glycosylation, glycosyltransferases, and glycan-binding receptors at the maternal–fetal interface, and their involvement in regulating the biology and pathological conditions associated with endometrial receptivity, placentation and maternal–fetal immunotolerance. Current knowledge limitations and future insights into the study of glycobiology in reproduction are discussed. SEARCH METHODS A comprehensive PubMed search was conducted using the following keywords: glycosylation, glycosyltransferases, glycan-binding proteins, endometrium, trophoblasts, maternal–fetal immunotolerance, siglec, selectin, galectin, repeated implantation failure, early pregnancy loss, recurrent pregnancy loss, preeclampsia, and fetal growth restriction. Relevant reports published between 1980 and 2023 and studies related to these reports were retrieved and reviewed. Only publications written in English were included. OUTCOMES The application of ultrasensitive mass spectrometry tools and lectin-based glycan profiling has enabled characterization of glycans present at the maternal–fetal interface and in maternal serum. The endometrial luminal epithelium is covered with highly glycosylated mucin that regulates blastocyst adhesion during implantation. In the placenta, fucose and sialic acid residues are abundantly presented on the villous membrane and are essential for proper placentation and establishment of maternal–fetal immunotolerance. Glycan-binding receptors, including selectins, sialic-acid-binding immunoglobulin-like lectins (siglecs) and galectins, also modulate implantation, trophoblast functions and maternal–fetal immunotolerance. Aberrant glycosylation is associated with repeated implantation failure, early pregnancy loss and various pregnancy complications. The current limitation in the field is that most glycobiological research relies on association studies, with few studies revealing the specific functions of glycans. Technological advancements in analytic, synthetic and functional glycobiology have laid the groundwork for further exploration of glycans in reproductive biology under both physiological and pathological conditions. WIDER IMPLICATIONS A deep understanding of the functions of glycan structures would provide insights into the molecular mechanisms underlying their involvement in the physiological and pathological regulation of early pregnancy. Glycans may also potentially serve as novel early predictive markers and therapeutic targets for repeated implantation failure, pregnancy loss, and other pregnancy complications. [ABSTRACT FROM AUTHOR]

BACKGROUND In IVF/ICSI treatment, the process of embryo implantation is the success rate-limiting step. Endometrial scratching has been suggested to improve this process, but it is unclear if this procedure increases the chance of implantation and live birth (LB) and, if so, for whom, and how the scratch should be performed. OBJECTIVE AND RATIONALE This individual participant data meta-analysis (IPD-MA) aims to answer the question of whether endometrial scratching in women undergoing IVF/ICSI influences the chance of a LB, and whether this effect is different in specific subgroups of women. After its incidental discovery in 2000, endometrial scratching has been suggested to improve embryo implantation. Numerous randomized controlled trials (RCTs) have been conducted, showing contradicting results. Conventional meta-analyses were limited by high within- and between-study heterogeneity, small study samples, and a high risk of bias for many of the trials. Also, the data integrity of several trials have been questioned. Thus, despite numerous RCTs and a multitude of conventional meta-analyses, no conclusion on the clinical effectiveness of endometrial scratching could be drawn. An IPD-MA approach is able to overcome many of these problems because it allows for increased uniformity of outcome definitions, can filter out studies with data integrity concerns, enables a more precise estimation of the true treatment effect thanks to adjustment for participant characteristics and not having to make the assumptions necessary in conventional meta-analyses, and because it allows for subgroup analysis. SEARCH METHODS A systematic literature search identified RCTs on endometrial scratching in women undergoing IVF/ICSI. Authors of eligible studies were invited to share original data for this IPD-MA. Studies were assessed for risk of bias (RoB) and integrity checks were performed. The primary outcome was LB, with a one-stage intention to treat (ITT) as the primary analysis. Secondary analyses included as treated (AT), and the subset of women that underwent an embryo transfer (AT+ET). Treatment-covariate interaction for specific participant characteristics was analyzed in AT+ET. OUTCOMES Out of 37 published and 15 unpublished RCTs (7690 participants), 15 RCTs (14 published, one unpublished) shared data. After data integrity checks, we included 13 RCTs (12 published, one unpublished) representing 4112 participants. RoB was evaluated as 'low' for 10/13 RCTs. The one-stage ITT analysis for scratch versus no scratch/sham showed an improvement of LB rates (odds ratio (OR) 1.29 [95% CI 1.02–1.64]). AT, AT+ET, and low-RoB-sensitivity analyses yielded similar results (OR 1.22 [95% CI 0.96–1.54]; OR 1.25 [95% CI 0.99–1.57]; OR 1.26 [95% CI 1.03–1.55], respectively). Treatment-covariate interaction analysis showed no evidence of interaction with age, number of previous failed embryo transfers, treatment type, or infertility cause. WIDER IMPLICATIONS This is the first meta-analysis based on IPD of more than 4000 participants, and it demonstrates that endometrial scratching may improve LB rates in women undergoing IVF/ICSI. Subgroup analysis for age, number of previous failed embryo transfers, treatment type, and infertility cause could not identify subgroups in which endometrial scratching performed better or worse. The timing of endometrial scratching may play a role in its effectiveness. The use of endometrial scratching in clinical practice should be considered with caution, meaning that patients should be properly counseled on the level of evidence and the uncertainties. [ABSTRACT FROM AUTHOR]

Breast cancer is the most common cancer in reproductive age women. The aim of this study is to assess the knowledge, attitude and intention on fertility preservation among women diagnosed to have breast cancer. This is a multi-centre cross-sectional questionnaire study. Reproductive age women diagnosed with breast cancer attending Oncology, Breast Surgery and Gynaecology Clinics and support groups were invited to participate. Women filled in paper or electronic form of the questionnaire. 461 women were recruited and 421 women returned the questionnaire. Overall, 181/410 (44.1%) women had heard of fertility preservation. Younger age and higher education level were significantly associated with increased awareness of fertility preservation. Awareness and acceptance of the different fertility preservation methods in reproductive age women with breast cancer was suboptimal. However, 46.1% women felt that their fertility concerns affected their decision for cancer treatment in some way. [ABSTRACT FROM AUTHOR]

Objective: To compare the intercycle variation of serum anti‐Mullerian hormone (AMH) and antral follicle count (AFC) measurements over four consecutive menstrual cycles. Design: Observational study with secondary analysis using data from two previous randomized controlled trials. Patients: Seventy‐eight women from two previous randomized trials on the effect of dehydroepiandrosterone pretreatment on ovarian response in women undergoing in vitro fertilization (IVF) treatment. Measurements: The intraclass correlation coefficients (ICC) for AFC and AMH across the four study cycles, as well as their predictive performance on poor ovarian response, were compared. Results: No significant difference was observed in AMH (p =.608) across the four study cycles. AFC was significantly higher at 4 weeks before ovarian stimulation compared with 0, 8 and 12 weeks before ovarian stimulation (p <.05, Conover posthoc test). Both single‐measures and average‐measures ICC were significantly higher with AMH than with AFC. The areas under the receiver operating characteristic curve of the four AFC measurements in predicting poor ovarian response (defined as three or less oocytes retrieved) in the IVF cycle ranged from 0.657 to 0.743 with no significant difference (p >.05) among the four cycles, whereas those of the four AMH measurement ranged from 0.730 to 0.780 with no significant difference (p >.05) among the four cycles. Conclusions: Although both AFC and AMH are good predictors of ovarian response, intercycle repeatability was significantly better with serum AMH than AFC measurement. Both have no significant difference in their predictive performance on poor ovarian response when assessed within three months before IVF treatment, hence allowing pre‐IVF assessment at more flexible timing. [ABSTRACT FROM AUTHOR]

Objectives: The aim of our study was to compare the live birth rate following fresh embryo transfer (ET) during in vitro fertilization (IVF) in women with or without endometrial compaction in thickness and volume between the day of human chorionic gonadotrophin (hCG) and the ET day. Methods: This is a retrospective analysis of infertile women undergoing the first IVF cycle with fresh ET. A single operator performed all the ultrasound measurements for endometrial thickness and endometrial volume using three‐dimensional ultrasound. Endometrial compaction was calculated as the difference of the measurement between the hCG day and ET day. The predictive values of age of women, number of embryos transferred, and endometrial compaction in thickness and volume on live birth were studied. Results: A total of 268 women who underwent the first IVF cycle with fresh ET between June 2005 and August 2006 were included in this retrospective analysis. Endometrial thickness was significantly higher on the ET day than the hCG day while endometrial volume was significantly smaller on the ET day than the hCG day. Women with a live birth were younger, had a higher serum estradiol level on the hCG day, and similar absolute or percentage change of endometrial thickness and volume when compared to those without a live birth. Conclusion: Endometrial thickness and volume compaction was not a significant predictor of live birth in the multivariate logistic regression model. Endometrial thickness and volume compaction did not affect the live birth rate in the fresh IVF cycle. [ABSTRACT FROM AUTHOR]