This study aimed to explore the associations between assisted reproductive technology (ART) modality and chorionicity in monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer. This retrospective cohort study analyzed 30,121 single embryo transfer cycles from January 2013 to December 2022 but focused on 251 monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer, including 144 monochorionic diamniotic (MCDA) twins and 107 dichorionic diamniotic (DCDA) twins. Regression analysis was performed to determine the risk factors for the subtypes of monozygotic twinning pregnancies after ART. Pregnancy complications and neonatal outcomes of the MCDA and DCDA groups were compared, and subgroup analyses among the in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and preimplantation genetic testing (PGT) groups were performed. The overall monozygotic twinning rate was 1.97

Adenomyosis, an estrogen-dependent condition characterized by endometrial invasion into the myometrium, is associated with reduced live birth rates and increased miscarriage risk in women undergoing assisted reproductive technologies (ART). Gonadotropin-releasing hormone agonists (GnRH-a) are commonly used for pretreatment before frozen-thawed embryo transfer (FET) in adenomyosis patients, but optimal duration remains unclear. Letrozole, an aromatase inhibitor, may enhance GnRH-a efficacy by mitigating its flare-up effect and reducing peripheral estrogen production, yet high-level evidence on their combined effect is lacking. This study aims to compare the live birth rate and other pregnancy outcomes between one and two doses of GnRH-a pretreatment with or without letrozole supplementation in women with adenomyosis undergoing FET. This is a 2 × 2 factorial, multi-center, open-label, randomized controlled trial (RCT) conducted at three reproductive medical centers in China, with a planned enrollment of 432 women aged 20–38 years with sonographically diagnosed adenomyosis scheduled for single blastocyst FET. This study is designed as a superiority trial. Recruitment will be conducted by trained clinical research coordinators. Participants are randomized in a 1:1:1:1 ratio to four arms: one dose of GnRH-a (3.75 mg), two doses of GnRH-a, one dose of GnRH-a with letrozole (2.5 mg daily for 28 days), or two doses of GnRH-a with letrozole (2.5 mg daily for 28 days). The primary outcome is live birth rate. Secondary outcomes include fertility outcomes, pregnancy and obstetric outcomes, and neonatal outcomes. Safety outcomes, including the incidence and severity of low-estrogen-related adverse events (e.g., hot flashes, bone loss, vaginal dryness) and other serious adverse events, will be collected and compared. An internal pilot phase will assess procedural feasibility when approximately 25 participants are randomized per arm. Data are collected via medical records and follow-up assessments up to 6 months postpartum. This factorial RCT is the first to assess the synergistic effects of GnRH-a dosage and letrozole supplementation, overcoming limitations of single-factor studies. By comprehensively evaluating pregnancy outcomes, the study aims to optimize pretreatment strategies, inform clinical guidelines, and improve pregnancy outcomes for adenomyosis patients undergoing FET. ClinicalTrials.gov NCT07065539. Registered on 14 July 2025. https://clinicaltrials.gov/study/NCT07065539. The first participant was enrolled in August 2025.

The gastrointestinal tract varies in structure and function by region, yet the drivers of region-specific inflammatory disease remain elusive. Here, a TNF-overexpressing murine model (TnfΔARE/+) of Crohn’s disease (CD) was used to investigate how pathobionts interact with host immune susceptibilities to drive region-specific disease. We identified the pathobiont Chlamydia muridarum, an intracellular bacterium and murine counterpart to the human sexually transmitted C. trachomatis, as a necessary and sufficient trigger for disease manifestation in the proximal/ascending colon, a common site of CD. In genetically susceptible hosts, pathobiont-triggered proximal colonic inflammation is driven by goblet cell responses, including tryptophan metabolism via indoleamine 2,3-dioxygenase 1 (IDO1). Our findings translate to human disease, where we demonstrate upregulation of epithelia-derived IDO1 in actively inflamed ascending colon specimens, but not actively inflamed terminal ileum specimens, of patients with CD. Our findings mechanistically reveal how genetic and microbial factors drive the manifestation of disease in a region-specific manner and provide a unique model to study CD specific to the ascending colon.

STUDY QUESTION:What are the risk factors associated with meiotic errors in blastocysts with mosaic biopsy results? SUMMARY ANSWER:Meiotic errors were identified in 3.9% of blastocysts with mosaic biopsy results and were correlated with high-level mosaicism, maternal origin, and advanced maternal age. WHAT IS KNOWN ALREADY:Chromosomal mosaicism mainly arises from postzygotic mitotic errors, except for rare events from rescued meiotic errors. Preimplantation genetic testing for aneuploidy origin (PGT-AO) can distinguish meiotic errors from mitotic errors; however, the clinical value of PGT-AO remains to be explored. STUDY DESIGN SIZE DURATION:A retrospective cohort of 391 blastocysts with mosaic biopsy results from a university-based fertility centre in China between January 2020 and December 2024 was analysed by PGT-AO. Risk factors associated with meiotic errors in blastocysts with mosaic biopsy results were explored. Pregnancy outcomes following 96 mosaic embryo transfers (METs) of embryos with mitotic errors were compared with those following transfer of 288 matched euploid embryos. Additionally, 7 donated blastocysts were separated for single-cell DNA sequencing. PARTICIPANTS/MATERIALS SETTING METHODS:The parental origin and cell-division origin were analysed in 391 blastocysts classified as euploid-aneuploid mosaic from a cohort of 8932 blastocysts detected using the single-nucleotide polymorphism (SNP) array. In the prospective study, pregnancy outcomes following METs of embryos with mitotic errors were compared with those following transfer of matched euploid embryos at a 1:3 ratio using propensity score matching. The primary outcome was the live birth/ongoing pregnancy rate (LB/OPR) of METs involving mitotic errors. Multivariate logistic regression analysis was used to evaluate risk factors for pregnancy outcomes. Prenatal and placental samples were analysed by SNP array and/or FISH for genetic verification. Single-cell DNA sequencing of 314 cells separated from 7 donated blastocysts (4 with high-level mosaicism, 2 with meiotic aneuploidy, and 1 with low-level mosaicism) was conducted to assess actual mosaicism. The chromosomal constitution of the blastocysts was comprehensively evaluated at the single-cell level, and concordance with the initial PGT-A results was assessed. MAIN RESULTS AND THE ROLE OF CHANCE:A SNP-based mosaicism quantification platform was established and validated using mixtures of single cells of varying ploidy to mimic clinical mosaic samples. In the retrospective cohort, the error origin was successfully determined for 384 of the 391 blastocysts with euploid-aneuploid mosaicism. The overall meiotic error rate was only 3.9% (15/384). Meiotic error was identified in 9.6% of blastocysts with mosaicism from women of advanced maternal age, which was significantly greater than the 3.0% observed in blastocysts with mosaicism from young women (OR = 3.43, 95% CI 1.12-10.46; P = 0.039). In addition, meiotic error was identified in 7.2% (10/139) of blastocysts with high-level mosaicism but 2.0% (5/245) of blastocysts with low-level mosaicism (OR = 3.72, 95% CI 1.25-11.12; P = 0.012). Meiotic error was also significantly greater in blastocysts with maternal-origin mosaicism than in those with paternal-origin mosaicism (8.9% vs 0.4%, OR = 21.66; P < 0.001). Clinical outcomes were comparable between METs and euploid embryo transfers, with no significant difference in LB/OPR (47.9% vs 52.8%, P = 0.409). Single-cell sequencing of donated blastocysts with high-level mosaicisms of mitotic errors demonstrated highly variable mosaic levels, ranging from a reproducibility rate of 8.7-100% for initial mosaic abnormalities at the single-cell level. LARGE SCALE DATA:Due to the individual privacy of the patients, the data are not publicly available. LIMITATIONS REASONS FOR CAUTION:Intrinsic technical noise cannot be completely distinguished from genuine mosaicism in the PGT-AO platform. The sample size of the MET cohort was limited, with few cases undergoing prenatal/postnatal genetic validation. In the single-cell study, the number of verified embryos was relatively small, and the threshold of copy number variation (CNV) detection was 10 Mb, which may have led to the underestimation of CNVs under 10 Mb. WIDER IMPLICATIONS OF THE FINDINGS:PGT-AO analysis demonstrated a low prevalence of meiotic errors in human blastocysts with mosaic biopsy results. PGT-AO is recommended for embryos from patients of advanced maternal age, embryos with high-level mosaicism, and embryos with maternal-origin mosaicism in PGT cycles. FUNDING:This study was supported by grants from the National Key Research and Development Program of China (No. 2023YFC2705503), National Natural Science Foundation of China (No. 82071716), Natural Science Foundation of Guangdong Province (No. 2025A1515010982), Key Clinical Technique of Guangzhou (No. 2023P-ZD19), and Medical Scientific Research Foundation of Guangdong Province (No. A2025203). DISCLOSURES:All authors declare no conflicts of interest.

Background and Objectives:Facioscapulohumeral muscular dystrophy type 1 (FSHD1) is caused by contraction of the D4Z4 repeat array at 4q35. Genetic diagnosis is particularly difficult in somatic mosaic cases, where conventional short-read sequencing cannot directly resolve pathogenic haplotypes. We aimed to establish a strategy using Nanopore ultra-long-read sequencing for accurate haplotype resolution and to demonstrate its clinical application in preimplantation genetic testing for monogenic disease (PGT-M). Methods:A male patient with somatic mosaic FSHD1 underwent Nanopore ultra-long-read sequencing to directly span the D4Z4 repeat array, identify contraction events, and distinguish normal and pathogenic haplotypes. Embryos derived from the patient were subsequently screened using this approach combined with short-read sequencing and Sanger sequencing to determine carrier status. Finally, Bionano optical genome mapping (OGM) was performed for prenatal validation. Results:Nanopore sequencing revealed 3 haplotypes with 4, 16, and 33 D4Z4 repeat units on 4qA, consistent with somatic mosaicism. Ultra-long reads enabled direct identification of a pathogenic 4-unit haplotype and precise haplotype phasing despite limited downstream SNPs. Methylation profiling confirmed hypomethylation of the pathogenic allele. Of 8 biopsied embryos, 5 were definitively classified as unaffected, 2 showed upstream recombination within a 224-kb region, and 1 carried the pathogenic haplotype. Integration of Nanopore, short-read sequencing, and Sanger sequencing resolved uncertain cases and reduced misclassification risk. An unaffected embryo was transferred, leading to the birth of a healthy infant. Prenatal OGM confirmed 17 and 33 D4Z4 repeat units without contraction, concordant with preimplantation results. Discussion:Nanopore ultra-long-read sequencing provides accurate detection of D4Z4 repeat contractions and haplotype resolution in somatic mosaic FSHD1, overcoming the limitations of conventional short-read sequencing. Applied to PGT-M, this approach ensured reliable embryo diagnosis and successful prevention of disease transmission. These findings support the broader potential of ultra-long-read sequencing for genetic testing and diagnosis of neurologic disorders involving complex repeat-mediated loci.

PURPOSE:Recurrent pregnancy loss (RPL) is frequently associated with embryonic aneuploidy, yet paternal genetic contributors remain poorly understood. In this study, we investigated the genetic cause of a couple with oligoasthenoteratozoospermia (OAT) and a history of RPL involving recurrent sex chromosome aneuploidies. METHODS:Evaluation included preimplantation genetic testing for aneuploidy (PGT-A) with parental origin analysis, semen analysis, and sperm fluorescence in situ hybridization (FISH). Whole-exome sequencing (WES) was performed to identify pathogenic variants, which were subsequently validated by Sanger sequencing. RESULTS:WES revealed a homozygous C12orf40 frameshift variant (c.232_233insTT) in the proband and his affected brother. Both brothers exhibited markedly elevated sperm sex chromosome error rates (proband nullisomy:18.8%; brother disomy:10.3%). Across three PGT-A cycles, only 41.7% (5/12) of the blastocysts were euploid, and 85.7% (6/7) of the aneuploid embryos involved sex chromosome abnormalities. Parental origin analysis indicated 72.7% of abnormalities were paternal in origin. CONCLUSION:This study identified a previously unreported phenotype of the C12orf40 c.232_233insTT variant, expanding its spectrum from complete meiotic arrest to incomplete arrest with severe meiotic errors and residual spermatogenesis. It provides the first evidence linking this variant to severe OAT and RPL, highlighting a crucial paternal genetic contributor to reproductive failure.

Genetic and environmental factors work together to cause islet beta cell failure, leading to type 2 diabetes. How these factors are integrated to regulate beta cells remains largely unclear. Based on our previous findings that the family of myelin transcription factors (MYT TFs; including MYT1, MYT1L and ST18) prevents mouse beta cell failure by repressing the overactivation of stress response, their regulation by obesity-related nutrition signals in human beta cells and their association with type 2 diabetes, we postulate that these factors prevent human beta cell failure under normal physiological conditions and obesity-related stress. MYT1 or ST18 were knocked down in primary human beta cells using shRNA. Beta cell survival, secretory function and gene expression were examined after islet cells were cultured in vitro or xenotransplanted into mice under normal conditions or obesity-related stress. In culture, MYT1-knockdown (KD) caused beta cell death, while ST18-KD compromised glucose-stimulated insulin secretion. Under obesity-induced stress as xenotransplants, ST18-KD also caused beta cell death. Accordingly, MYT1-KD deregulated several genes and gene sets related to cell death and cellular stress response, while ST18-KD deregulated those regulating stress response, mitochondria and ion channels. Corresponding to these gene expression changes, ST18-KD reduced glucose-stimulated Ca2+ influx in beta cells. In addition, the MYT1- and ST18-regulated genes were enriched for type-2-diabetes-associated loci, with an enrichment of 2.05-fold relative to the random distribution of beta cell-expressed genes. The MYT TFs complement each other to integrate genetic and environmental factors to prevent beta cell failure and type 2 diabetes, with their major effects exerted on beta cell viability and/or Ca2+ influx.

STUDY QUESTION Is E-cadherin (CDH1) expressed on the free apical surface of endometrial epithelial cells (EECs) involved in embryo attachment?SUMMARY ANSWER Embryonic signals induced apical expression of endometrial CDH1, which facilitated attachment via hetero-cellular CDH1 homophilic binding.WHAT IS KNOWN ALREADY Understanding human blastocyst-endometrium interaction helps fertility treatment by facilitating the evaluation of endometrial receptivity and blastocyst quality. CDH1 is an adhesion molecule commonly known for the maintenance of epithelial integrity through adherens junction formation on the lateral membranes of adjacent epithelial cells. The apical region of some epithelia also expressed CDH1 of unknown function.STUDY DESIGN, SIZE, DURATION Laboratory experimental study.PARTICIPANTS/MATERIALS, SETTING, METHODS The potential apical cell plasma membrane proteins participating in adhesion between blastocysts and EEC were identified by comparing the surface proteomes of polar trophectoderm-like trophoblastic spheroids (BAP-EB) and receptive EEC. The apical surface expression of CDH1 in human blastocysts and primary EEC was confirmed by live-cell immunofluorescent staining. Antibody blocking and gene knockdown approaches were used to study the functional roles of hetero-cellular homophilic binding of CDH1. The adhesiveness of EEC and polar trophectoderm-like cells was confirmed by atomic force microscopy upon gene knockdown. The embryonic signals induced endometrial apical surface relocations of CDH1 and its stabilizer delta-1 catenin (CTNND1) were studied by treatments with conditioned media of BAP-EB and human blastocysts, as well as with HCG. The correlations of endometrial CDH1 and CTNND1 with pregnancy outcomes were confirmed by western blotting analysis of their protein expressions in EEC and immunofluorescent staining of endometrium collected from women who gave live birth, those who failed to become pregnant after IVF, and those with repeated implantation failure.MAIN RESULTS AND THE ROLE OF CHANCE We identified 27 pairs of potential interactive cell plasma membrane transmembrane proteins between BAP-EB and EEC, and CDH1 homophilic binding was one of them. CDH1 was localized to the apical surface of receptive EEC and the polar trophectoderm of human blastocysts. The CDH1 expression in EEC was higher during the window of implantation than those at the pre-receptive phase. With the use of atomic force microscopy, we revealed that the adhesiveness of the apical surface of polar trophectoderm-like cells and EEC decreased when CDH1 was silenced. The attachment rates of BAP-EB onto EEC were decreased when the surface CDH1 of BAP-EB and/or the EEC was blocked by an anti-CDH1 antibody, indicating that homophilic binding of trophectodermal CDH1 with endometrial CDH1 mediated the attachment of BAP-EB onto EEC. Besides cell surface adhesiveness, knockdown of CDH1 or CTNND1 in EEC also reduced expression of adhesion-related molecules and BAP-EB attachment. The conditioned media of BAP-EB and human blastocysts and HCG enhanced apical expression of CDH1 in EEC, suggesting embryonic signals, in particular, modulated the expression of CDH1 and stimulated the adhesion of EEC. The protein expression of CDH1 was significantly higher in EEC isolated from patients who gave live birth as compared to those with repeated implantation failure. Importantly, the expression of CDH1 in the apical region of the luminal epithelium of the endometrium from fertile women was also significantly higher than that from women with repeated implantation failure.LARGE SCALE DATA none.LIMITATIONS, REASONS FOR CAUTION This study only includes in vitro experiments. Due to the limited availability of human blastocysts and difficulty in long-term expandable culture of primary EEC, embryo surrogates BAP-EB and endometrial adenocarcinoma cell lines were used for most of the experimental work. The sample size of the primary EEC for protein analysis in this study was small, and the 2D culture of primary EEC in vitro might have impaired its native epithelial polarity.WIDER IMPLICATIONS OF THE FINDINGS Endometrial factors can lead to infertility, but the exact molecules involved in endometrial receptivity remain unclear. Human endometrial receptivity is best assessed by determining whether a human blastocyst can attach and implant onto the endometrium of interest. With the use of a human embryo surrogate named BAP-EB, we demonstrated the important roles of CDH1 and CTNND1 in human embryo attachment. In particular, we showed that homophilic binding between trophectodermal CDH1 and epithelial CDH1 was one of the major mediators of the first contact in embryo-maternal interaction. Embryo-derived factors induced apical redistribution of CTNND1 and CDH1 in the EEC. Most importantly, the expression of CDH1 on the apical region of EEC represented endometrial receptivity. The results strengthen our understanding of embryo-maternal interaction in humans, and CDH1 could potentially be used for predicting IVF outcomes, which helps clinicians to better counsel the couples who fail with ART.STUDY FUNDING/COMPETING INTEREST(S) This study was supported by Grant for Fertility Innovation 2016 from Merck; Health and Medical Research Fund (grant numbers: HMRF 04151546; 10212996; 11222296) from the Food and Health Bureau, Government of the Hong Kong Special Administrative Region; InnoHK initiative of the Innovation and Technology Commission of the Hong Kong Special Administrative Region Government (Health@InnoHK); Shenzhen Science and Technology Program (Grant No. KQTD20190929172749226); General Research Fund (grant number: 17212922); Collaborative Research Fund C7100-22GF from the Research Grants Council of Hong Kong; and Shenzhen Sanming Project of Medicine (SZSM202211014). The authors have no conflicts of interest to declare.TRIAL REGISTRATION NUMBER N/A.

Infertility is a global issue affecting 17.5

Non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) can detect embryo chromosomal aneuploidy by analyzing the cell-free DNA in embryo culture media. However, evidence for its clinical efficacy is insufficient. In this investigator-initiated, multicenter, double-blind, randomised controlled trial, women aged 35-42 who agreed to single frozen-thawed blastocyst transfer with at least two blastocysts were enrolled from 13 fertility centers in China. Eligible participants were randomly assigned (1:1) to the niPGT-A(n = 594) or morphology group(n = 595) using a computer-generated block randomization list, stratified by participating center. In the niPGT-A group, embryos were selected for the first transfer cycle based on niPGT-A results, whereas in the morphology group, embryos were selected according to standard morphological criteria. The primary outcome was the ongoing pregnancy rate (OPR) (pregnancy beyond 12 weeks). Secondary outcomes included clinical pregnancy, miscarriage (pregnancy loss before the 28th week, with those before the 12th week as early miscarriages), and live birth rates. The trial has been completed. The modified intention-to-treat population(mITT) contained 581 couples in the morphology group and 571 in the niPGT-A group. Among 1152 randomised patients, OPR was 38.7% (221/571) in the niPGT-A group and 36.8% (214/581) in the morphology group (adjusted p = 0.49). There were no statistically significant between group differences in the rates of clinical pregnancy (47.6% vs 49.9%, adjusted p = 0.49), miscarriage (21.0% vs 27.6%, adjusted p = 0.06) and live birth (37.0% vs 35.5%, adjusted p = 0.59). Early miscarriage was significantly lower in the niPGT-A group compared with that of the morphology group (18.0% vs 25.2%, adjusted p = 0.03). Maternal and neonatal outcomes did not differ significantly between groups. No serious adverse events were reported in either group. The results indicated that there was insufficient evidence to establish a statistically significant difference in OPR between the two treatment arms. The results of this trial do not provide a basis for recommending routine use of niPGT-A in this good-prognosis population (NCT04339166). Non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) can detect embryo chromosomal aneuploidy by analyzing the cell-free DNA in embryo culture media, but evidence for clinical efficacy is insufficient. Here the authors report a randomised controlled trial involving 1,152 women aged 35–42 years that shows no difference in the primary outcome of ongoing pregnancy rate between the intervention group with niPGT-A and the control group with morphological selection.

In response to obesity-related metabolic stress, islet β cells adapt (or compensate) by increasing their secretory function and mass. Yet, for unknown reasons, this compensation is reversed in some individuals at some point to induce β-cell failure and overt type 2 diabetes. We have previously shown that transcription factor Myt3 (St18) and its paralogs, Myt1 and Myt2 (Myt1l), prevent β-cell failure. Myt3 was induced at post-transcriptional levels by obesity-related stress in both mouse and human β cells. Its downregulation, at both protein and transcript levels, accompanied human β-cell dysfunction during type 2 diabetes development. Single-nucleotide polymorphisms in MYT3 were associated with an increased risk of human diabetes. We now show that disrupting an upstream ORF that overlaps with the main Myt3 ORF can enhance Myt3 translation without metabolic stress but decreases it under high-fat diet challenges in islet β cells. Consequently, this deregulation results in β-cell dysfunction and glucose intolerance in mice, accompanied by compromised expression of several β-cell function genes under high-fat diet challenge. These findings suggest that stress-induced Myt3 translation is a part of the compensation mechanism that prevents β-cell failure in mice.

OBJECTIVES:This retrospective study compares pregnancy outcomes in polycystic ovary syndrome (PCOS) patients across different controlled ovarian stimulation (COS) protocols-specifically GnRH antagonist and GnRH agonist cycles-combined with various frozen embryo transfer(FET) preparation methods, such as hormone replacement therapy (HRT) and ovulatory cycles. Despite the known variations in COS and FET protocols, the optimal combination for improving pregnancy outcomes in this population remains unclear. METHODS:We analyzed the first FET cycles of 2510 patients with PCOS at our center between January 2017 and September 2024. Baseline characteristics and pregnancy outcomes were compared using the Kruskal‒Wallis test, the chi-square (χ²) statistic, the Bonferroni correction for multiple comparisons, and inverse probability of treatment weighting (IPTW) adjustment. RESULTS:After IPTW adjustment, no significant differences were observed in live birth rates or other key reproductive outcomes among the four protocol combinations (all P > 0.05). Exploratory analyses revealed nonsignificant trends, suggesting two patterns: 1) GnRH agonist (vs. antagonist) COS protocols were associated with lower point estimates for the risks of preterm PROM and HDP; 2) ovulation (vs. HRT) cycles for FET preparation were similarly associated with lower point estimates for these risks. CONCLUSIONS:For PCOS patients, live birth success is equivalent regardless of COS/FET protocol combination, supporting flexible treatment personalization. Clinical decision-making involves a critical trade-off: GnRH agonist protocols and ovulation FET cycles may be associated with a trend toward lower obstetric morbidity, potentially linked to the promotion of a more physiological ovulatory milieu. This balance between immediate iatrogenic risk and long-term pregnancy health warrants further study.

Background: Polycystic ovary syndrome (PCOS) is characterized by substantial inter-individual variability in ovarian sensitivity to recombinant follicle-stimulating hormone (rFSH) during controlled ovarian stimulation (COS). Clinically applicable tools for personalized dosing in this population remain limited. Methods: This retrospective single-center study (2013-2024) analyzed 369 PCOS patients undergoing GnRH antagonist protocols who achieved optimal ovarian responses (10-20 oocytes with at least 40% of follicles ≥ 16 mm in diameter on trigger day). The final retrospective dataset was randomly split into modeling (n = 258) and validation (n = 111) groups. A multivariate linear regression model incorporating age, BMI, basal FSH, basal LH, AMH, and AFC was developed to estimate the average daily rFSH dose. Model performance was evaluated using correlation analysis, prediction error metrics, and calibration assessment. Results: Age, BMI, and basal FSH were positively associated with average daily rFSH dose, whereas basal LH, AMH, and AFC were negatively associated. The model explained 40.4% of the variability in average daily rFSH dose. In the modeling cohort, 77.9% of estimated doses fell within ±20% of the observed values, with a moderate correlation between predicted and observed doses (ρ = 0.646). In the validation cohort, 67.6% of estimates met the predefined accuracy threshold (ρ = 0.676). Calibration analyses demonstrated robust agreement between predicted and observed doses. Conclusions: By integrating endocrine markers, ovarian reserve indicators, and clinical characteristics, this study provides a practical example of personalized medicine in COS in women with PCOS. The internally validated approach may support individualized rFSH dosing during COS and serve as a basis for future development of decision support tools in this specific population.

OBJECTIVE:To compare the efficacy of different COH protocols on pregnancy outcomes in adenomyosis patients. STUDY DESIGN:A real-world retrospective cohort study analyzed 1486 IVF-ET cycles in adenomyosis patients who received COH regimens between 2018 and 2021. Pregnancy outcomes were compared among patients under different COH protocols. RESULTS:The short-acting long protocol achieved the highest live birth (47.92%) and cumulative clinical pregnancy (68.84%) rates. The antagonist protocol showed lower fresh-cycle pregnancy (36.63% vs. 52.10%, p = 0.036), live birth (21.78% vs. 36.55%, p = 0.009), and cumulative clinical pregnancy rates (39.31% vs. 53.29%, p < 0.001) compared to the long/ultra-long protocol. Multivariable logistic regression confirmed that the COH protocol was an independent predictor of both clinical pregnancy (Wald χ² = 8.127, p = 0.043) and cumulative clinical pregnancy (Wald χ² = 40.344, p < 0.001). In patients <35 years with a normal ovarian reserve (anti-Müllerian hormone ≥ 1.2 ng/mL), live birth rates and cumulative clinical pregnancy rates were similar between the antagonist protocol and long/ultra-long protocols (27.59% vs. 44.94%, p = 0.098; 63.83% vs. 63.87%, p = 0.995), with significantly less gonadotropin used in the antagonist protocol. CONCLUSIONS:In adenomyosis patients, the long/ultra-long provided better fresh-cycle outcomes. While the antagonist protocol had lower overall pregnancy rates, it preserved cumulative pregnancy rates in young patients with normal ovarian reserves and reduced gonadotropin exposure.

The mammalian intestine regenerates rapidly after damage, yet the clonal dynamics and species-specific regulation of different populations remain poorly understood. Here we used synthetic or naturally occurring DNA alterations to reconstruct clonal histories of the mouse and human intestinal epithelium at single-cell resolution. In mice, we uncovered the clonal architecture of different cell types and their roles in regeneration, supporting a hierarchical regenerative response model. We identified a rare embryonic precursor population that persisted in the adult and was crucial for regeneration after irradiation. This population was marked by Tob2, which is required for nuclear transport of Ascl2. A parallel clonal analysis of 65 human colonic biopsies revealed secretory lineage bias and an age-associated decline in clonal diversity in the distal colon. Unlike highly proliferative murine Lgr5+ stem cells, human LGR5+ cells were found largely quiescent, revealing species-specific difference in clonal potency, and suggesting a distinct regulation of intestinal stemness.

OBJECTIVES:To evaluate the association of GGN repeat polymorphism of androgen receptor (AR) with ovarian reserve and ovarian response in controlled ovarian stimulation (COS). METHODS:This genetic association study was conducted among a total of 361 women aged ≤40 years with basal FSH≤12 U/L undergoing the GnRH-agonist long protocol for COS in a university-affiliated IVF center. GGN repeat in the AR gene was analyzed with Sanger sequencing. The primary endpoint was the number of antral follicle counts (AFCs), and the secondary endpoints were stimulation days, total dose of gonadotropin (Gn) used, total number of retrieved oocytes, ovarian sensitivity index, and follicular output rate. RESULTS:The GGN repeat in exon 1 of the AR gene ranged from 13 to 24, and the median repeat length was 22. Based on the genotypes (S for GGN repeats <22, L for GGN repeats ≥22), the patients were divided into 3 groups: SS, SL, and LL. Generalized regression analysis indicated that the number of AFCs in group SS was significantly lower than those in group SL (adjusted β=1.8, 95% CI: 0.2-3.4, P=0.024) and group LL (adjusted β=1.5, 95% CI: 0.2-2.7, P=0.021). No significant difference was observed in the number of AFCs between group SL and group LL (P>0.05). Generalized regression analysis indicated no significant differences in ovarian stimulation parameters among the 3 groups, either before or after adjusting for confounding factors (P>0.05). CONCLUSIONS:GGN repeat length on the AR gene is associated with AFC but not with ovarian response in Chinese women, indicating that AR gene polymorphisms may affect ovarian reserve.

Human patient-derived organoids from the small intestine and colon have become commonplace in research focusing on cellular function, metabolism, and cancer progression. Many studies using organoids will build upon literature that uses organoids cultured in different base mediums, either commercial-generated or lab-generated. Little to no research has been undertaken to evaluate whether organoids cultured from different medium can be interchangeably analyzed and if varying mediums yield genetically, morphologically, transcriptionally comparable organoids. This study aims to evaluate small intestine and colonic organoids under differing medium sources, both to determine the best culture condition for maintaining origin tissue identity whilst determining if culturing medium affects the ability to cross-analyze mediums. We have directly compared organoids derived from the small intestine and colon in multiple mediums including the Organoid Growth Medium (OGM) and Organoid Differentiation Medium (ODM) from StemCell Technologies, as well as multiple lab-generated mediums including those using conditioned medium from either individual Wnt3a, R-Spondin1, and Noggin (WRN) or from the combination cell line, L-WRN. Organoids grown in OGM and ODM maintained more cystic structures regardless of origin or culture duration whereas organoids in lab-generated mediums were slightly more budded and darker – classically interpreted as more differentiated. Utilizing immunofluorescence on whole-mount and paraffin-embedded organoids, we found that organoids grown in OGM and ODM have a higher number of MKI67-positive cells compared to organoids grown in lab-generated mediums. This is consistent with both flow cytometry and single cell RNA-sequencing (scRNA-seq) analysis, where commercial medium consistently produces more proliferative organoids than lab-generated mediums. Further scRNA-seq analysis highlights that organoids grown in OGM and ODM are highly skewed toward stem and progenitor cell types, while lab-generated mediums produce more differentiated cell types, while maintaining a small population of progenitors. Lastly, gene set enrichment analysis of organoids grown in commercial and lab-generated mediums highlights that organoids grown in commercial mediums, such as OGM, have a high correlation with mitotic fetal cells, rather than either the small intestinal or colonic origin. Yet, organoids grown in lab-generated mediums can both unbiasedly-identify their tissue of origin and region-specific cell types. Overall, these results convey that commercial mediums derive more stem-like organoids both morphologically and transcriptionally, concordant with multiple techniques suggesting these organoids are highly proliferative and revert to a more fetal-like state. In contrast, lab-generated mediums derive organoids with more differentiated cell types that maintain more of their tissue identity both morphologically and transcriptionally. Together these suggest that commercial and lab-generated mediums must not be used interchangeably and highlight the key need to standardize organoid culturing conditions when utilizing comparative analyses. This research is supported by grant 2444112 from the NSF GRFP, grant AI125181 from the National Institutes of Health, and grant U54CA274367 from the National Cancer Institute. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Programmed cell death protein 1 (PD-1) expression on T cells has been implicated in the pathogenesis of autoimmune diseases; however, the functional role of programmed death-ligand 1 (PD-L1) expression on B cells remains insufficiently characterized, particularly in the context of CD4+ T cell-mediated regulation in systemic lupus erythematosus (SLE). Flow cytometric analysis revealed that PD-L1+ B cells exhibited upregulated surface expression of the co-stimulatory molecules CD80 and CD86, alongside a concomitant downregulation in the expression of the antigen-presenting molecule human leukocyte antigen DR (HLA-DR). Furthermore, an elevated frequency of class-switched PD-L1+ B cells was observed in the peripheral blood of patients with SLE. Using co-culture systems and transwell assays, we demonstrated that CD4+ T cells modulate PD-L1 expression on B cells via direct cell-cell interactions. Mechanistically, this regulation was shown to be dependent on bidirectional CD40/CD40L signaling. These findings advance our understanding of PD-L1-mediated immunoregulation in SLE pathogenesis and identify PD-L1+ B cells as potential targets for therapeutic intervention.

OBJECTIVE:To study whether antibiotic treatment improves the pregnancy outcomes of frozen-thawed embryo transfer (FET) in infertile patients diagnosed with mild chronic endometritis (CE). DESIGN:Propensity score-matched cohort study. SUBJECTS:Women undergoing hysteroscopy with endometrial biopsy for previous failures of embryo transfer, history of recurrent pregnancy loss (RPL), abnormal uterine bleeding or suspicious of endometrial lesions (i.e., polyps, uterine adhesion) seen on transvaginal ultrasound. Mild CE was defined as 1-4 CD138+ endometrial stromal plasmacytes (ESPCs) per high-power field (HPF). EXPOSURE:Patients with mild CE received 14 days of empirical antibiotic therapy (doxycycline, 100 mg, twice daily or levofloxacin lactate, 500 mg, once daily plus metronidazole, 200 mg, 3 times daily) or no treatment before single blastocyst FET. MAIN OUTCOME MEASURES:The primary outcome was live birth. Secondary outcomes included other fertility outcomes such as clinical pregnancy and early pregnancy loss, as well as perinatal outcomes. RESULTS:A total of 681 patients were diagnosed with mild CE, of whom 303 received antibiotics and 378 did not receive antibiotics. After propensity score matching, 303 pairs of patients were generated for comparative analysis. Live birth rate (LBR) between the antibiotics and untreated group was not significantly different (47.5% vs. 51.8%, relative risk [RR] 0.92, 95% confidence interval [CI] 0.78-1.08). All other reproductive, pregnancy and perinatal outcomes were also comparable. No significant differences were observed in fertility outcomes between the antibiotics and untreated cohorts across a range of cut-off values for the CD138 categories (from 1 ESPCs/HPF to ≤4 ESPCs/HPF), although severity of infection had no impact on the prognosis. CONCLUSION:In this cohort study, we did not find an indication that antibiotic treatment improves pregnancy outcomes in patients with mild CE. Additionally, a higher CD138 category did not affect the prognosis.

Previous studies have shown that due to the presence of endometrium progesterone resistance in patients with endometriosis, it is considered that higher levels of progesterone may be required to achieve live birth during programmed frozen-thawed embryo transfer (FET) cycles. Currently, the optimal progesterone support in FET cycles remains a contentious issue, and it mainly focused on the general infertile population, without specific attention to infertile patients with endometriosis. This study aimed to compare the pregnancy outcomes between vaginal or intramuscular progesterone administration in patients with endometriosis, and to determine whether the stage of endometriosis moderates the differences. This retrospective cohort study included patients with endometriosis who underwent their first single frozen-thawed blastocyst transfer in a programmed cycle from January 2018 to April 2024 at a university-affiliated reproductive medical center. According to the routes of luteal support, patients were divided into vaginal progesterone and intramuscular progesterone groups. Analyses were conducted using multivariate regression models and subgroup analysis. Interaction tests were employed to determine whether the revised American Society for Reproductive Medicine (r-ASRM) stages of endometriosis moderated the differences between the routes of progesterone administration and pregnancy outcomes. A total of 825 programmed frozen-thawed blastocyst transfer cycles were included in the analysis, with 362 cases using vaginal progesterone and 463 cases using intramuscular progesterone. In the overall cohort, clinical pregnancy rate of the vaginal progesterone group was 49.17