Simulated lunar microgravity transiently arrests growth and induces osteocyte-chondrocyte lineage differentiation in human Wharton's jelly stem cells.

Human Wharton's jelly stem cells (hWJSCs) are multipotent stem cells that are extensively employed in biotechnology applications. However, the impact of simulated lunar microgravity (sµG) on the growth, differentiation, and viability of this cell population is incompletely characterized. We aimed to determine whether acute (72 h) exposure to sµG elicited changes in growth and lineage differentiation in hWJSCs and if putative changes were maintained once exposure to terrestrial gravity (1.0 G) was restored. hWJSCs were cultured under standard 1.0 G conditions prior to being passaged and cultured under sµG (0.16 G) using a random positioning machine. Relative to control, hWJSCs cultured under sµG exhibited marked reductions in growth but not viability. Cell population expression of characteristic stemness markers (CD 73, 90, 105) was significantly reduced under sµG conditions. hWJSCs had 308 significantly upregulated and 328 significantly downregulated genes when compared to 1.0 G culture conditions. Key markers of cell replication, including MKI67, were inhibited. Significant upregulation of osteocyte-chondrocyte lineage markers, including SERPINI1, MSX2, TFPI2, BMP6, COMP, TMEM119, LUM, HGF, CHI3L1 and SPP1, and downregulation of cell fate regulators, including DNMT1 and EZH2, were detected in sµG-exposed hWJSCs. When returned to 1.0 G for 3 days, sµG-exposed hWJSCs had accelerated growth, and expression of stemness markers increased, approaching normal (i.e. 95%) levels. Our data support earlier findings that acute sµG significantly reduces the cell division potential of hWJSCs and suggest that acute sµG-exposure induces reversible changes in cell growth accompanied by osteocyte-chondrocyte changes in lineage differentiation.

Validation of the first-trimester machine learning model for predicting pre-eclampsia in an Asian population.

OBJECTIVES: To evaluate the performance of an artificial intelligence (AI) and machine learning (ML) model for first-trimester screening for pre-eclampsia in a large Asian population. METHODS: This was a secondary analysis of a multicenter prospective cohort study in 10 935 participants with singleton pregnancies attending for routine pregnancy care at 11-13+6 weeks of gestation in seven regions in Asia between December 2016 and June 2018. We applied the AI+ML model for the first-trimester prediction of preterm pre-eclampsia (<37 weeks), term pre-eclampsia (≥37 weeks), and any pre-eclampsia, which was derived and tested in a cohort of pregnant participants in the UK (Model 1). This model comprises maternal factors with measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor (PlGF). The model was further retrained with adjustments for analyzers used for biochemical testing (Model 2). Discrimination was assessed by area under the receiver operating characteristic curve (AUC). The Delong test was used to compare the AUC of Model 1, Model 2, and the Fetal Medicine Foundation (FMF) competing risk model. RESULTS: The predictive performance of Model 1 was significantly lower than that of the FMF competing risk model in the prediction of preterm pre-eclampsia (0.82, 95% confidence interval [CI] 0.77-0.87 vs. 0.86, 95% CI 0.811-0.91, P = 0.019), term pre-eclampsia (0.75, 95% CI 0.71-0.80 vs. 0.79, 95% CI 0.75-0.83, P = 0.006), and any pre-eclampsia (0.78, 95% CI 0.74-0.81 vs. 0.82, 95% CI 0.79-0.84, P < 0.001). Following the retraining of the data with adjustments for the PlGF analyzers, the performance of Model 2 for predicting preterm pre-eclampsia, term pre-eclampsia, and any pre-eclampsia was improved with the AUC values increased to 0.84 (95% CI 0.80-0.89), 0.77 (95% CI 0.73-0.81), and 0.80 (95% CI 0.76-0.83), respectively. There were no differences in AUCs between Model 2 and the FMF competing risk model in the prediction of preterm pre-eclampsia (P = 0.135) and term pre-eclampsia (P = 0.084). However, Model 2 was inferior to the FMF competing risk model in predicting any pre-eclampsia (P = 0.024). CONCLUSION: This study has demonstrated that following adjustment for the biochemical marker analyzers, the predictive performance of the AI+ML prediction model for pre-eclampsia in the first trimester was comparable to that of the FMF competing risk model in an Asian population.

Healthcare in the era of climate change and the need for environmental sustainability.

ABSTRACT: Climate change is an existential threat to humanity. While the healthcare sector must manage the health-related consequences of climate change, it is a significant contributor to greenhouse gas emissions, responsible for up to 4.6% of global emission, aggravating global warming. Within the hospital environment, the three largest contributors to greenhouse gas emissions are the operating theatre, intensive care unit and gastrointestinal endoscopy. Knowledge of the health-related burden of climate change and the potential transformative health benefits of climate action is important to all health professionals, as they play crucial roles in effecting change. This article summarises the available literature on the impact of healthcare on climate change and efforts in mitigation, focusing on the intrinsic differences and similarities across the operating theatre complex, intensive care unit and gastrointestinal endoscopy unit. It also discusses strategies to reduce carbon footprint.

A scoping review of ChatGPT's role in healthcare education and research.

OBJECTIVES: To examine and consolidate literature regarding the advantages and disadvantages of utilizing ChatGPT in healthcare education and research. DESIGN/METHODS: We searched seven electronic databases (PubMed/Medline, CINAHL, Embase, PsycINFO, Scopus, ProQuest Dissertations and Theses Global, and Web of Science) from November 2022 until September 2023. This scoping review adhered to Arksey and O'Malley's framework and followed reporting guidelines outlined in the PRISMA-ScR checklist. For analysis, we employed Thomas and Harden's thematic synthesis framework. RESULTS: A total of 100 studies were included. An overarching theme, "Forging the Future: Bridging Theory and Integration of ChatGPT" emerged, accompanied by two main themes (1) Enhancing Healthcare Education, Research, and Writing with ChatGPT, (2) Controversies and Concerns about ChatGPT in Healthcare Education Research and Writing, and seven subthemes. CONCLUSIONS: Our review underscores the importance of acknowledging legitimate concerns related to the potential misuse of ChatGPT such as 'ChatGPT hallucinations', its limited understanding of specialized healthcare knowledge, its impact on teaching methods and assessments, confidentiality and security risks, and the controversial practice of crediting it as a co-author on scientific papers, among other considerations. Furthermore, our review also recognizes the urgency of establishing timely guidelines and regulations, along with the active engagement of relevant stakeholders, to ensure the responsible and safe implementation of ChatGPT's capabilities. We advocate for the use of cross-verification techniques to enhance the precision and reliability of generated content, the adaptation of higher education curricula to incorporate ChatGPT's potential, educators' need to familiarize themselves with the technology to improve their literacy and teaching approaches, and the development of innovative methods to detect ChatGPT usage. Furthermore, data protection measures should be prioritized when employing ChatGPT, and transparent reporting becomes crucial when integrating ChatGPT into academic writing.

Integration-free induced pluripotent stem cells from three endangered Southeast Asian non-human primate species.

Advanced molecular and cellular technologies provide promising tools for wildlife and biodiversity conservation. Induced pluripotent stem cell (iPSC) technology offers an easily accessible and infinite source of pluripotent stem cells, and have been derived from many threatened wildlife species. This paper describes the first successful integration-free reprogramming of adult somatic cells to iPSCs, and their differentiation, from three endangered Southeast Asian primates: the Celebes Crested Macaque (Macaca nigra), the Lar Gibbon (Hylobates lar), and the Siamang (Symphalangus syndactylus). iPSCs were also generated from the Proboscis Monkey (Nasalis larvatus). Differences in mechanisms could elicit new discoveries regarding primate evolution and development. iPSCs from endangered species provides a safety net in conservation efforts and allows for sustainable sampling for research and conservation, all while providing a platform for the development of further in vitro models of disease.

Upregulation of hepatic nuclear receptors in extremely preterm ovine fetuses undergoing artificial placenta therapy.

OBJECTIVE: Extremely preterm infants have low Nuclear Receptor (NR) expression in their developing hepatobiliary systems, as they rely on the placenta and maternal liver for compensation. NRs play a crucial role in detoxification and the elimination of both endogenous and xenobiotic substances by regulating key genes encoding specific proteins. In this study, we utilized an Artificial Placenta Therapy (APT) platform to examine the liver tissue expression of NRs of extremely preterm ovine fetuses. This fetal model, resembling a "knockout placenta," lacks placental and maternal support, while maintaining a healthy extrauterine survival. METHODS: Six ovine fetuses at 95 ± 1 d gestational age (GA; term = ∼150 d)/∼600 g delivery weight were maintained on an APT platform for a period of 120 h (APT Group). Six age-matched, in utero control fetuses were delivered at 99-100 d GA (Control Group). Fetal liver tissue samples and blood samples were collected at delivery from both groups and assessed mRNA expression of NRs and target transporters involved in the hepatobiliary transport system using quantitative PCR. Data were tested for group differences with ANOVA (p < .05 deemed significant). RESULTS: mRNA expression of NRs was identified in both the placenta and the extremely preterm ovine fetal liver. The expression of HNF4α, LRH1, LXR, ESR1, PXR, CAR, and PPARα/γ were significantly elevated in the liver of the APT Group compared to the Control Group. Moreover, target transporters NTCP, OATP1B3, BSEP, and MRP4 were upregulated, whereas MRP2 and MRP3 were unchanged. Although there was no evidence of liver necrosis or apoptotic changes histologically, there was an impact in the fetal liver of the ATP group at the tissue level with a significant increase in TNFα mRNA, a cytokine involved in liver inflammation, and blood elevation of transaminases. CONCLUSION: A number of NRs in the fetal liver were significantly upregulated after loss of placental-maternal support. However, the expression of target transporter genes appeared to be insufficient to compensate role of the placenta and maternal liver and avoid fetal liver damage, potentially due to insufficient excretion of organic anions.

Diffuse reflectance spectroscopy and imaging for non-invasive objective assessment of genitourinary syndrome of menopause: a pilot study.

The genitourinary symptom of menopause (GSM) affects up to 65% of women, resulting in symptoms such as vulvovaginal dryness, discomfort, and dysuria, which significantly impacts quality of life. The current assessment methods rely on subjective questionnaires that can be influenced by individual differences, as well as invasive measurements that are time-consuming and not easily accessible. In this study, we explore the potential of a non-invasive and objective assessment tool called diffuse reflectance spectroscopy and imaging (DRSI) to evaluate tissue chromophores, including water, lipid, oxyhemoglobin, and deoxyhemoglobin. These measurements provide information about moisture content, lipid levels, oxygen saturation, and blood fraction, which can serve as surrogate markers for genital estrogen levels. Our findings reveal distinct differences in these chromophores among pre, peri, and postmenopausal subjects. By using lipid and blood fraction tissue chromophores in a K-Nearest Neighbour classifier model, we achieved a prediction accuracy of 65% compared to vaginal maturation index (VMI) that is clinically used to assess estrogen-related hormonal changes. When age was included as the third feature, the accuracy increased to 78%. We believe that by refining the study protocol and configuring the fiber probe to examine tissue chromophores both in the superficial vulva skin for epidermal water content and the deeper layers, DRSI has the potential to provide objective diagnosis and aid in monitoring the treatment outcome of GSM.

Perceptions of healthcare professionals regarding labour induction and augmentation: A qualitative systematic review.

BACKGROUND: Labour induction and augmentation procedures are commonly used in maternity units with or without medical indications. Research shows that healthcare professionals play a significant role in women's childbirth decisions. AIM: To consolidate healthcare professionals' perceptions about labour induction and augmentation. METHODS: Seven electronic databases were searched from their inception dates till January 2023: PubMed, Embase, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest Dissertations, and Theses Global. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis and Sandelowski and Barroso's guidelines guided this review. Included studies' quality was appraised by the Critical Appraisal Skills Program tool. Data were thematically synthesised. Review findings were assessed using the Grading of Recommendations Assessment, Development, and Evaluation-Confidence in the Evidence from Reviews of Qualitative research approach. FINDINGS: Three main themes were identified from the 17 included studies: 1) Making sense of the phenomenon, 2) Two sides of the coin, and 3) The enlightened path ahead. DISCUSSION: Healthcare professionals' labour induction and augmentation decisions were affected by personal (knowledge and moral philosophies), and external factors (women, community members, colleagues, and healthcare institutions). Some clinicians were unfamiliar with the proper labour induction/augmentation procedures, while others were worried about their decisions and outcomes. CONCLUSION: Suggestions for improvement include conducting labour induction/augmentation training for clinicians, having sufficient resources in facilities, and developing appropriate labour induction/augmentation clinical guidelines. Women and their partners, community members, and traditional healers could benefit from receiving labour induction/augmentation education. To improve health outcomes, healthcare professionals could deliver woman-centred care and collaborate.

Chorioamnionitis: An Update on Diagnostic Evaluation.

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Insights of healthcare professionals regarding waterbirths and water immersion during labour: A mixed studies review.

AIM: To consolidate healthcare professionals' insights about waterbirths and water immersion during labour. DESIGN: Mixed studies review. DATA SOURCES: Seven electronic databases were searched from their inception dates till June 2023: PubMed, Embase, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest Dissertations and Theses Global. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and Pluye and Hong's mixed studies review framework guided this review. The quality of included studies was evaluated using the Mixed Methods Appraisal Tool. Findings were synthesized using the convergent qualitative synthesis method, and results were thematically analysed using Braun and Clarke's framework. RESULTS: Three main themes were identified from the 22 included studies: (1) believing in waterbirths, (2) opposing forces and (3) plotting the course ahead. CONCLUSION: Healthcare professionals reported different views about waterbirths and water immersion practices; midwives were most likely to support these practices, followed by nurses and lastly, few physicians supported them. Reasons for opposing waterbirths include insufficient training and support from colleagues as well as concerns about work efficiency, waterbirth safety and litigation issues. IMPACT: The available evidence suggests the need to provide waterbirth training for healthcare professionals, equip healthcare facilities with necessary waterbirth-related infrastructure and develop appropriate waterbirth policies/guidelines. Healthcare professionals could also consider providing antenatal waterbirth education to women and obtain women's feedback to improve current policies/guidelines. Future research should explore the views of different types of healthcare professionals from more diverse cultures. REPORTING METHOD: The PRISMA guidelines. NO PATIENT OR PUBLIC CONTRIBUTION: Systematic review.

Artificial placenta support of extremely preterm ovine fetuses at the border of viability for up to 336 hours with maintenance of systemic circulation but reduced somatic and organ growth.

Introduction: Artificial placenta therapy (APT) is an experimental life support system to improve outcomes for extremely preterm infants (EPI) less than 1,000 g by obviating the need for pulmonary gas exchange. There are presently no long-term survival data for EPI supported with APT. To address this, we aimed to maintain 95d-GA (GA; term-150d) sheep fetuses for up to 2 weeks using our APT system. Methods: Pregnant ewes (n = 6) carrying singleton fetuses underwent surgical delivery at 95d GA. Fetuses were adapted to APT and maintained for up to 2 weeks with constant monitoring of key physiological parameters and extensive time-course blood and urine sampling, and ultrasound assessments. Six age-matched in-utero fetuses served as controls. Data were tested for group differences with ANOVA. Results: Six APT Group fetuses (100%) were adapted to APT successfully. The mean BW at the initiation of APT was 656 ± 42 g. Mean survival was 250 ± 72 h (Max 336 h) with systemic circulation and key physiological parameters maintained mostly within normal ranges. APT fetuses had active movements and urine output constantly exceeded infusion volume over the experiment. At delivery, there were no differences in BW (with edema in three APT group animals), brain weight, or femur length between APT and in-utero Control animals. Organ weights and humerus lengths were significantly reduced in the APT group (p < 0.05). Albumin, IGF-1, and phosphorus were significantly decreased in the APT group (p < 0.05). No cases of positive blood culture were detected. Conclusion: We report the longest use of APT to maintain extremely preterm fetuses to date. Fetal systemic circulation was maintained without infection, but growth was abnormal. This achievement suggests a need to focus not only on cardiovascular stability and health but also on the optimization of fetal growth and organ development. This new challenge will need to be overcome prior to the clinical translation of this technology.

Third-Generation Single-Molecule Sequencing for Preimplantation Genetic Testing of Aneuploidy and Segmental Imbalances.

BACKGROUND: Current strategies for preimplantation genetic testing for aneuploidy or structural rearrangements (PGT-A/SR) rely mainly on next-generation sequencing (NGS) and microarray platforms, which are robust but require expensive instrumentation. We explored the suitability of third-generation single-molecule sequencing as a PGT-A/SR screening platform for both aneuploidy and segmental imbalance. METHODS: Single-cell and multicell replicates from aneuploid or segmentally unbalanced cell lines (n = 208) were SurePlex-amplified, randomized, and subjected to (a) Nanopore-based single-molecule sequencing (Oxford Nanopore Technologies) and (b) NGS using a leading commercial PGT-A solution (Illumina VeriSeq PGS). Archival SurePlex-amplified trophectoderm biopsy samples (n = 96) previously analyzed using the commercial kit were blinded and reanalyzed using Nanopore. RESULTS: Nanopore-based PGT-A identified the specific aberration in 95.45% (84/88) and 97.78% (88/90) of single-/multicells with an aneuploidy or segmental imbalance (10-30.5 Mb), respectively. Comparison against the commercial kit's results revealed concordances of 98.86% (87/88) and 98.89% (89/90) for the aneuploid and segmentally unbalanced (10-30.5 Mb aberration) samples, respectively. Detection sensitivity for smaller segmental imbalances (5-5.8 Mb aberration, n = 30) decreased markedly on both platforms. Nanopore-based PGT-A reanalysis of trophectoderm biopsy samples was 97.92% (94/96) concordant with the commercial kit results. CONCLUSION: Up to 24 SurePlex-amplified single-cell, multicell, or trophectoderm samples could be sequenced in a single MinION flow-cell for subsequent preimplantation genetic testing for aneuploidy or structural rearrangements (PGT-A/SR) analysis, with results obtainable in ≤3 days and at per-sample costs that are competitive with commercial offerings. Nanopore's third-generation single-molecule sequencing represents a viable alternative to current commercial NGS-based PGT-A solutions for aneuploidy and segmental imbalance (≥10 Mb) screening of single-/multicell or trophectoderm biopsy samples.

Development of machine learning models to predict gestational diabetes risk in the first half of pregnancy.

BACKGROUND: Early prediction of Gestational Diabetes Mellitus (GDM) risk is of particular importance as it may enable more efficacious interventions and reduce cumulative injury to mother and fetus. The aim of this study is to develop machine learning (ML) models, for the early prediction of GDM using widely available variables, facilitating early intervention, and making possible to apply the prediction models in places where there is no access to more complex examinations. METHODS: The dataset used in this study includes registries from 1,611 pregnancies. Twelve different ML models and their hyperparameters were optimized to achieve early and high prediction performance of GDM. A data augmentation method was used in training to improve prediction results. Three methods were used to select the most relevant variables for GDM prediction. After training, the models ranked with the highest Area under the Receiver Operating Characteristic Curve (AUCROC), were assessed on the validation set. Models with the best results were assessed in the test set as a measure of generalization performance. RESULTS: Our method allows identifying many possible models for various levels of sensitivity and specificity. Four models achieved a high sensitivity of 0.82, a specificity in the range 0.72-0.74, accuracy between 0.73-0.75, and AUCROC of 0.81. These models required between 7 and 12 input variables. Another possible choice could be a model with sensitivity of 0.89 that requires just 5 variables reaching an accuracy of 0.65, a specificity of 0.62, and AUCROC of 0.82. CONCLUSIONS: The principal findings of our study are: Early prediction of GDM within early stages of pregnancy using regular examinations/exams; the development and optimization of twelve different ML models and their hyperparameters to achieve the highest prediction performance; a novel data augmentation method is proposed to allow reaching excellent GDM prediction results with various models.

LPCAT1 levels in the placenta, the maternal plasma and the fetal plasma do not predict fetal lung responses to glucocorticoids in a sheep model of pregnancy.

INTRODUCTION: Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is important for saturated phosphatidylcholine (Sat-PC) production in the lung. Sat-PC is a critical component of pulmonary surfactant, which maintains low alveolar surface tension, facilitating respiration. Previous studies have reported an association between maternal and fetal LPCAT1 levels and neonatal lung function. Using a sheep model of pregnancy, we investigated a potential correlation between glucocorticoid-induced lung maturation and LPCAT1 mRNA and/or protein levels in the fetal lung, the placenta, the fetal plasma, and the maternal plasma. METHODS: Eighty seven single pregnant ewes received maternal intramuscular injections of betamethasone. A sub-group of five animals had both maternal and fetal catheters installed to allow for sequential sampling from both plasma compartments. Lambs were surgically delivered under terminal anaesthesia between 2 and 8 days after initial ANS treatment, at a gestational age of 121-123 days. Lambs were ventilated for 30 min to determine functional lung maturation before being euthanized for necropsy and sample collection. Fetal lung, placenta, and fetal and maternal plasma samples were used to analyse LPCAT1 gene expression and protein levels. RESULTS: The expression of LPCAT1 mRNA in the fetal lung was significantly corelated to Sat-PC levels at 8 days (R2 = 0.23, p < 0.001) and lung maturation status overall (gas exchange efficiency as determined by measurements of lamb PaCO2 during ventilation, R2 = 0.20, p < 0.001). Similarly, fetal lung LPCAT1 mRNA was also significantly correlated with the individual durability of ANS effects on fetal lung maturation (R2 = 0.20, p < 0.001). Although ANS therapy altered LPCAT1 mRNA expression in the placenta, observed changes were independent of fetal lung maturation outcomes. Neither maternal nor fetal plasma LPCAT1 levels were changed by ANS therapy over the period, including in analysis of serial maternal and fetal samples from chronically catheterised animals. DISCUSSION: LPCAT1 expression in the fetal lung was associated with the durability of glucocorticoid effects on fetal lung maturation. However, LPCAT1 expression in the placenta, the fetal plasma, and the maternal plasma was neither associated with, nor predictive of fetal lung maturation after glucocorticoid treatment in a sheep model of pregnancy.

'Parentbot - A Digital healthcare Assistant (PDA)': A mobile application-based perinatal intervention for parents: Development study.

OBJECTIVE: To describe the development procedure of a mobile application-based parenting support program with integrated chatbot features entitled Parentbot - a Digital healthcare Assistant (PDA) for multi-racial Singaporean parents across the perinatal period. METHODS: The PDA development process was guided by the combined information systems research framework with design thinking modes, and Tuckman's model of team development. A user acceptability testing (UAT) process was conducted among 11 adults of child-bearing age. Feedback was obtained using a custom-made evaluation form and the 26-item User Experience Questionnaire. RESULTS: The combined information systems research framework with design thinking modes helped researchers to successfully create a PDA prototype based on end-users' needs. Results from the UAT process indicated that the PDA provided participants with an overall positive user experience. Feedback gathered from UAT participants was used to enhance the PDA. CONCLUSION: Although the effectiveness of the PDA in improving parental outcomes during the perinatal period is still being evaluated, this paper highlights the key details of developing a mobile application-based parenting intervention which future studies could learn from. PRACTICE IMPLICATIONS: Having carefully planned timelines with margins of delays, extra funds to resolve technical issues, team cohesion, and an experienced leader can facilitate intervention development.

Maternal dendritic cells influence fetal allograft response following murine in-utero hematopoietic stem cell transplantation.

BACKGROUND: Intrauterine hematopoietic stem cell transplantation (IUT), potentially curative in congenital haematological disease, is often inhibited by deleterious immune responses to donor cells resulting in subtherapeutic donor cell chimerism (DCC). Microchimerism of maternal immune cells (MMc) trafficked into transplanted recipients across the placenta may directly influence donor-specific alloresponsiveness, limiting DCC. We hypothesized that dendritic cells (DC) among trafficked MMc influence the development of tolerogenic or immunogenic responses towards donor cells, and investigated if maternal DC-depletion reduced recipient alloresponsiveness and enhanced DCC. METHODS: Using transgenic CD11c.DTR (C57BL/6) female mice enabled transient maternal DC-depletion with a single dose of diphtheria toxin (DT). CD11c.DTR females and BALB/c males were cross-mated, producing hybrid pups. IUT was performed at E14 following maternal DT administration 24 h prior. Bone marrow-derived mononuclear cells were transplanted, obtained from semi-allogenic BALB/c (paternal-derived; pIUT), C57BL/6 (maternal-derived; mIUT), or fully allogenic (aIUT) C3H donor mice. Recipient F1 pups were analyzed for DCC, while maternal and IUT-recipient immune cell profile and reactivity were examined via mixed lymphocyte reactivity functional assays. T- and B-cell receptor repertoire diversity in maternal and recipient cells were examined following donor cell exposure. RESULTS: DCC was highest and MMc was lowest following pIUT. In contrast, aIUT recipients had the lowest DCC and the highest MMc. In groups that were not DC-depleted, maternal cells trafficked post-IUT displayed reduced TCR & BCR clonotype diversity, while clonotype diversity was restored when dams were DC-depleted. Additionally, recipients displayed increased expression of regulatory T-cells and immune-inhibitory proteins, with reduced proinflammatory cytokine and donor-specific antibody production. DC-depletion did not impact initial donor chimerism. Postnatal transplantation without immunosuppression of paternal donor cells did not increase DCC in pIUT recipients; however there were no donor-specific antibody production or immune cell changes. CONCLUSIONS: Though maternal DC depletion did not improve DCC, we show for the first time that MMc influences donor-specific alloresponsiveness, possibly by expanding alloreactive clonotypes, and depleting maternal DC promotes and maintains acquired tolerance to donor cells independent of DCC, presenting a novel approach to enhancing donor cell tolerance following IUT. This may have value when planning repeat HSC transplantations to treat haemoglobinopathies.