Search Results (2,210)

Ovarian reserve and reproductive life are closely linked concepts in female reproductive biology. The ovarian reserve consists of primordial follicles and refers to the number and quality of oocytes (eggs) remaining in the ovaries at any given time. Follicular dynamics shape a woman’s reproductive lifespan, ultimately leading to menopause. Elucidating the underlying genetic and molecular pathways of follicle maturation and depletion is thus crucial for understanding menopausal onset and progression, both in normal and pathophysiological contexts, such as primary ovarian insufficiency, defined as menopause before the age of 40. A key factor in ovarian differentiation and fertility maintenance is FOXL2, a forkhead family transcription factor that plays a crucial role in follicle formation and development, ovarian maintenance, and sex determination. By employing a ChIP-Seq approach in mice, we identified a previously unreported binding of FOXL2 to a Tsc1 regulatory region. Our data, along with a thorough literature review, support the hypothesis that FOXL2-mediated activation of Tsc1 in granulosa cells can help maintain primordial follicles in a dormant state by suppressing mTORC1 signalling. Understanding the mechanisms behind ovarian reserve may lay the foundation for developing novel fertility preservation strategies, improving fertility treatment protocols and promoting in vitro activation of cryopreserved ovarian tissue to support folliculogenesis. Full article

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. Full article

Broodstock conditioning involves maintaining adult animals in optimal environmental conditions to ensure that the largest number of breeders reach maturity. We evaluated the gonadal development and the occurrence of spawns in the yellow clam (Amarilladesma mactroides) and estimated the duration of conditioning that results in the highest maturity rate. Clams were kept buried in a 10 cm sand bed within Ø = 15 cm containers. A concentrate of Isochrysis galbana and Chaetoceros muelleri was supplied daily. Four conditioning periods (14, 28, 45 and 60 days) with four replicates were used. On the day of collection and at the end of each conditioning period, clams were induced to spawn with thermal shocks (16.7 °C to 26 °C) and sperm. The first spawns were observed on day 28, but only 50% of the males and 33% of the females were mature, and their mean oocyte diameter (36.33 µm) was smaller than the minimum (45–50 µm) considered for ready-to-spawn clams. However, on day 45, all males and females were mature (mean oocyte diameter = 45.14 µm) and 1102 × 10³ eggs were released. To ensure a high maturity rate, yellow clams should be conditioned in captivity for 45 days. Monitoring gonadal development in the wild to collect clams at advanced stages of gonadal development may be a less expensive strategy worth considering. Full article

High-efficiency Ovum Pick-Up (OPU) and in vitro embryo production (IVP) are critical for the genetic improvement of high-value Wagyu cattle. However, oxidative stress and mitochondrial dysfunction during oocyte maturation remain major bottlenecks limiting blastocyst yield. This study investigated the role of inhibin in Wagyu oocyte competence through two independent proof-of-concept approaches. In the in vivo active immunization model, thirty Wagyu donors were immunized with a recombinant inhibin protein (INHA group), resulting in a significant increase in the number of recovered cumulus–oocyte complexes (COCs) (461 vs. 279, p < 0.05) and the proportion of high-quality oocytes compared to controls. Oocytes from the INHA group exhibited improved cytoplasmic maturation and mitochondrial function, characterized by higher membrane potential (ΔΨm, JC-1 ratio: 1.55 ± 0.06 vs. 0.83 ± 0.08, p < 0.05), elevated ATP content (2.35 ± 0.07 vs. 1.63 ± 0.03 pmol/oocyte, p < 0.05), and increased NADPH levels. Furthermore, the INHA group showed significantly reduced reactive oxygen species (ROS) accumulation and an increased GSH/GSSG ratio (8.48 ± 0.18 vs. 6.25 ± 0.09, p < 0.05), indicating restored redox homeostasis. Independently, in the in vitro anti-inhibin antibody (AIA) supplementation model, AIA supplementation during oocyte maturation significantly improved the nuclear maturation rate (92.96% ± 1.04%), blastocyst formation rate (56.63% ± 2.36%), and total cell number compared to controls (p < 0.05). Notably, AIA-derived blastocysts achieved a significantly higher pregnancy rate (78.65% ± 1.57%) following transfer. Collectively, these findings demonstrate that targeting inhibin mitigates oxidative injury and stabilizes mitochondrial bioenergetics, providing two distinct, physiology-based strategies for optimizing Wagyu oocyte yield and embryo production. Full article

In vitro embryo production (IVP) has emerged as a crucial tool in assisted reproduction and animal biotechnology. A key factor in this process is in vitro oocyte maturation (IVM), a critical process preceding fertilization that directly influences embryo quality. FLI supplementation, composed of fibroblast growth factor (FGF2), leukemia inhibitory factor (LIF), and insulin-like growth factor 1 (IGF1), has been shown to facilitate the IVM process to mimic essential aspects of in vivo oocyte development, and therefore, promote higher rates of oocyte maturation, embryonic viability, blastocyst formation, and improve the number of live animals born after embryo transfer. Individually or together, these components participate in signaling pathways that are crucial for improving oocyte competence and early embryo development. This review highlights the individual and combined roles of FGF2, LIF, and IGF1 in maturation and embryo culture medium, their influence on subsequent embryonic development, and their signaling pathways. Additionally, the incorporation of antioxidants and amino acids as supplementary components in combination with FLI is explored as a strategy to mitigate oxidative stress and enhance metabolic support during IVM and embryo culture. Together, these elements can significantly improve IVP outcomes, providing a potential pathway for optimizing the efficiency of embryo production in various species. Full article

Objectives: To systematically evaluate the efficacy and safety of intraovarian platelet-rich plasma (PRP) administration in women with diminished ovarian reserve (DOR) and related conditions, given the growing clinical interest and the conflicting evidence from uncontrolled and controlled studies. Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Comprehensive searches were performed in PubMed, Web of Science, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Scopus up to January 2026. Eligible studies included randomized controlled trials (RCTs), prospective cohort studies, and before–after studies investigating PRP-based interventions in women diagnosed with DOR, premature ovarian insufficiency (POI), or poor ovarian response (POR). Given the limited availability of controlled data, these populations were analyzed together with cautious interpretation. Study quality was assessed using the Joanna Briggs Institute (JBI) checklists and the Critical Appraisal Skills Programme (CASP) tool for RCTs. Pooled estimates were calculated using random- or fixed-effects models depending on heterogeneity (I²). Results: Nineteen studies involving 1794 women were included, of which two were randomized controlled trials. In single-arm and before–after analyses, PRP administration was associated with increases in serum anti-Müllerian hormone (AMH) levels and antral follicle count (AFC), as well as a reduction in serum follicle-stimulating hormone (FSH). In addition, the number of metaphase II (MII) oocytes retrieved and transferable embryos increased following PRP treatment. However, pooled analyses of controlled studies, including RCTs, did not demonstrate consistent improvements in mature oocyte yield compared with control groups. In single-arm analyses, the pooled clinical pregnancy rate and live birth rate following PRP treatment were 15.5% (95% CI: 11.1–21.2%) and 10.7% (95% CI: 6.7–16.6%), respectively. No major procedure-related adverse events were reported across included studies. Conclusions: In conclusion, intraovarian PRP is associated with improvements in ovarian reserve markers such as AMH and AFC in uncontrolled studies. However, evidence from randomized controlled trials does not demonstrate a consistent benefit in pregnancy and live birth. Well-designed RCTs with standardized protocols are needed before clinical recommendation. Full article

Background and Clinical Significance: Mixed-phenotype acute leukemia (MPAL) is a rare hematologic malignancy characterized by the co-expression of myeloid and lymphoid markers and is associated with poor prognosis. Myeloid sarcoma (MS), particularly in the mediastinum, is an uncommon extramedullary manifestation and is rarely reported in association with MPAL. Case Presentation: We report a rare case of mediastinal MS with biphenotypic features and pericardial extension occurring concurrently with MPAL, highlighting diagnostic challenges, therapeutic strategies, and long-term outcomes. We describe the clinical course, diagnostic workup, treatment, and follow-up of a 21-year-old woman who presented with cardiac tamponade secondary to a mediastinal mass. Histopathology and immunophenotyping established the diagnosis of mediastinal MS associated with MPAL (B/myeloid, NOS). Management included surgical cytoreduction, intensive induction chemotherapy, and consolidation with allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an unrelated donor. Fertility preservation with oocyte retrieval, in vitro fertilization (IVF), and embryo cryopreservation was performed prior to conditioning. A focused literature review of MPAL cases with extramedullary involvement was conducted. The patient achieved complete remission following induction therapy and underwent allo-HSCT. Despite the historically poor prognosis of mediastinal MS and MPAL, she remains in sustained complete remission 13 years after diagnosis. A literature review identified only eight reported cases of MPAL with extramedullary disease, with mediastinal involvement described in a single case and allo-HSCT performed in only two patients. Conclusions: This case illustrates a rare presentation of MPAL with mediastinal myeloid sarcoma and cardiac tamponade, demonstrating that aggressive multimodal therapy including allo-HSCT may achieve durable remission even in high-risk presentations. Early multidisciplinary management and consideration of fertility preservation are essential in young patients. Full article

To improve the vitrification efficiency of bovine germinal vesicle (GV) oocytes, the use of hydroxyapatite (HA) nanoparticles as a novel cryopreservation additive represents a promising approach. This study aimed to investigate the effects of HA nanoparticles and permeable cryoprotective agents (CPAs) on the ultrastructure, developmental competence, and gene expression of bovine GV oocytes following vitrification. Oocytes were vitrified in vitrification solutions containing HA nanoparticles of different sizes (20, 40, or 60 nm) and concentrations (0.01%, 0.05%, or 0.1%) to determine the optimal conditions based on survival rate, mitochondrial membrane potential (MMP) level, and developmental competence. Subsequently, the synergistic effects of HA nanoparticles and permeable CPAs (VS: 20% EG + 20% DMSO; VS1: 17.5% EG + 17.5% DMSO) were further evaluated. The optimal treatment (40 nm 0.05% HA nanoparticles) significantly increased MMP level, and improved developmental competence compared with the vitrified control group (p < 0.05). Among the vitrified groups, vitrified oocytes in the VS1-HA group (combining HA nanoparticles with reduced concentrations of permeable CPAs) exhibited the highest MMP level (1.89), maturation rate (50.39%), cleavage rate (27.07%), and blastocyst rate (10.53%) (p < 0.05). Ultrastructural analysis further revealed that the VS1-HA group maintained more intact zona pellucida structures and showed reduced mitochondrial swelling compared with the vitrified control group. Moreover, the expression levels of genes associated with zona pellucida formation (ZP3), mitochondrial fusion (MFN1), and chromatin remodeling (NPM2) were significantly upregulated in the VS1-HA group relative to the vitrified control group. Overall, these findings indicate that the combination of HA nanoparticles with lower concentrations of permeable CPAs enhances MMP level, alleviates vitrification-induced ultrastructural damage, and upregulates the expression of key developmental genes, thereby improving the developmental competence of vitrified bovine GV oocytes. Full article

Background: Oocyte cryopreservation has emerged as a viable fertility preservation method, gaining popularity among women delaying motherhood for non-medical reasons. This study examines the awareness, perceptions, and social factors influencing young women’s decisions regarding elective oocyte cryopreservation (EOC), intending to identify key demographic and psychosocial determinants. Methods: A cross-sectional study was conducted using an online survey distributed via digital platforms between November 2024 and February 2025. A structured questionnaire comprising 31 multiple-choice questions assessed participants’ sociodemographic characteristics, reproductive health history, lifestyle factors, and perceptions of fertility and EOC. Statistical analyses included Chi-square tests, t-tests, and binary logistic regression to identify factors associated with willingness to undergo EOC. Results: A total of 390 women (mean age 22.57 ± 1.41 years) participated. Awareness of oocyte cryopreservation was remarkably high (93.1%). Significant predictors for the intention to undergo EOC included higher educational attainment (Master’s level) (OR = 4.27, 95% CI: 1.10–16.48) and living in a student dormitory (OR = 15.39, 95% CI: 4.86–48.71). Conversely, living with a partner showed a non-significant downward trend in interest (OR = 0.07, 95% CI: 0.01–1.43). Psychological factors, specifically anxiety about future fertility (OR = 0.23, 95% CI: 0.08–0.62 for moderate vs. high anxiety) and a strong desire for future parenthood (OR = 21.75, 95% CI: 1.45–32.99), also emerged as primary drivers of women’s reproductive decisions. Conclusions: Despite high awareness, the willingness to undergo elective oocyte cryopreservation remains limited. Targeted fertility education and supportive policies are needed to address misconceptions, financial barriers, and psychological concerns influencing reproductive decision-making. Further research should explore longitudinal trends in women’s attitudes toward EOC. Full article

Nanotechnology, based on nanoparticles, has become an emerging interdisciplinary tool in reproductive biotechnology, offering innovative opportunities to improve fertilization efficiency and reproductive performance in farm animals. The purpose of this review is to provide an updated synthesis of current research on nanoparticle-based approaches that enhance in vitro fertilization outcomes and other assisted reproductive technologies. The focus is on the biological mechanisms, potential benefits, and limitations of nanoparticle use in animal reproduction. Nanoparticles—including gold, silver, zinc oxide, selenium, and magnetic iron oxide—exhibit distinctive physicochemical properties that enable targeted interactions with gametes and reproductive cells. When used in semen extenders or culture media, nanoparticles improve sperm motility, acrosome and membrane integrity, and reduce oxidative stress and apoptosis. These effects contribute to enhanced fertilization rates and higher embryo developmental competence. In addition, nanoparticles can function as carriers for hormones, antioxidants, and growth factors, stabilizing reagents essential for oocyte maturation, sperm capacitation, and early embryo culture. The review also discusses nanopurification (selectively isolating and removing particles) and nanosorting (separating or organizing nanoscale objects) techniques that allow for non-invasive selection of viable gametes, and fluorescence- and magnet-assisted sorting systems that increase precision in sperm sexing. The mechanical aspects of nanoparticle–cell interactions are analyzed, emphasizing the influence of particle size, dose, and surface modification on both biological efficacy and cytotoxicity. Safety, toxicological concerns, and regulatory frameworks—including International Organization for Standardization (ISO) standards and European Commission recommendations—are critically reviewed to highlight the need for harmonized biocompatibility criteria. Although nanoparticle use in animal reproduction remains largely experimental, accumulated evidence demonstrates its potential to improve reproductive efficiency and reduce economic losses. Integrating nanoparticle-based systems with existing reproduction platforms may represent a transformative step toward sustainable and precision-driven livestock breeding. Full article

The gonadal development of Japanese eels (Anguilla japonica) plays a crucial role in the success of artificial breeding. Soy isoflavones, a class of phytoestrogens commonly found in aquafeeds, have shown potential in enhancing gonad development in fish. The present study evaluated the effects of dietary soy isoflavones on gonadal development, growth performance, histology, sex hormone levels, vitellogenin content, and expression of related genes in female Japanese eel broodstock. A 4-week feeding trial was conducted with 120 two-year-old female eels randomly assigned to four groups and fed diets containing 0 (C), 0.1 (L), 0.5 (M), and 0.9 (H) mg/g of soy isoflavones. The results indicated that gonadal development was enhanced in the M and H groups, as evidenced by a significantly higher gonadosomatic index (GSI) and increased oocyte cross-sectional area (CSA) in M group, and greater nutrient accumulation in both the M and H groups. The expression of er and cyp19a genes in the ovary was downregulated in the treatment groups, leading to decreased serum estradiol (E2) and increased testosterone levels. Furthermore, hepatic vtg gene expression was upregulated in the M and H groups, though VTG protein content remained unchanged, suggesting an initiation of vitellogenesis at the transcriptional level. In conclusion, dietary soy isoflavones at 0.5–0.9 mg/g provide an effective pretreatment strategy to enhance early ovarian development in Japanese eel broodstock, potentially improving their responsiveness to subsequent hormonal induction in artificial breeding programs. Full article

Background and Objectives: Evidence on the impact of adherence to the Mediterranean diet alone—without supplementation—on serum and follicular fluid fatty acid profiles and assisted reproduction outcomes remains limited. This study evaluated the effects of a pre-treatment Mediterranean diet intervention on these parameters. Materials and Methods: In this prospective, non-randomized controlled trial, 32 women undergoing infertility treatment were allocated to a Mediterranean diet intervention group (n = 16) or a control group (n = 16). The intervention lasted 12 weeks, and adherence was assessed using validated dietary indices. Serum and follicular fluid fatty acid profiles were analyzed, and implantation and pregnancy outcomes were recorded. Results: The diet group showed increased ω-6 and ω-3 intake with decreased LA/ALA and ω-6/ω-3 ratios. In the control group, serum EPA + DHA levels declined, whereas in the diet group serum LA/ALA decreased. Follicular fluid in the intervention group had lower EPA + DHA and ω-6 ratios. Diet adherence correlated positively with MII oocytes (r = 0.797) and pronuclei (r = 0.741). No significant associations were found between follicular fluid fatty acids and IVF outcomes. A total of four implantation events were observed (intervention: n = 3; control: n = 1). Two of the implantations in the intervention group resulted in live births, while the remaining implantation events did not result in live birth. Conclusions: A Mediterranean diet-aligned dietary intervention may induce favorable changes in blood and follicular fluid parameters; however, the underlying metabolic mechanisms warrant further investigation. Three implantations were observed in the intervention group and one in the control group; given the low number of events, comparisons of live birth outcomes should be interpreted with caution. Overall, the findings regarding ART outcomes and clinical translation remain exploratory due to the limited sample size. Well-designed randomized controlled trials in which ART and clinical endpoints are defined as primary outcomes are needed. Full article

Background: Does maternal body mass index (BMI) influence embryo morphokinetics in fresh embryo transfer cycles, and how does this relate to clinical outcomes and obstetric complications? Methods: A retrospective cohort study was conducted on 2238 fresh embryo transfer (ET) cycles, categorized into four BMI groups: underweight, normal weight, overweight, and obese. Baseline characteristics, stimulation parameters, hormonal profiles, morphokinetic data, and pregnancy and delivery outcomes were analyzed. Results: Higher BMI was associated with more anovulatory infertility and greater endometrial thickness. Peak estradiol and estradiol-to-oocyte ratios declined progressively with increasing BMI, despite preserved oocyte yield and embryo quality scores. Interestingly, the underweight group exhibited a significantly distinct biphasic morphokinetics developmental pattern compared with the overweight and obese groups. Pregnancy rates, including clinical and live birth, did not differ significantly across BMI groups. However, obese women had markedly higher cesarean section rates (51.9% vs. ~25–28% in other groups) and a non-significant trend toward more gestational diabetes. Other perinatal outcomes, such as preeclampsia and preterm birth, were not significantly different. Conclusions: In fresh IVF cycles, a higher BMI does not impair pregnancy achievement but is linked to altered hormonal response and increased obstetric risk, particularly cesarean delivery. These findings highlight the importance of preconception counseling and targeted obstetric management for women with elevated BMI undergoing fresh ET. Full article

Female reproductive aging is associated with a progressive decline in oocyte competence and reduced success in assisted reproductive technologies. While chromosomal abnormalities, mitochondrial dysfunction, and DNA damage have been extensively studied, these mechanisms do not fully explain developmental arrest in chromosomally euploid embryos or the variability in embryo competence. Human oocytes enter a transcriptionally quiescent state during meiotic maturation and rely almost entirely on the regulated translation of stored maternal messenger RNAs to support fertilization and early embryonic development until zygotic genome activation. In this context, translational fidelity becomes a critical determinant of proteome integrity and cellular function. Age-related alterations affecting ribosomal RNA integrity, transfer RNA modification, aminoacylation accuracy, and translational regulatory networks may impair the precision, timing, and coordination of protein synthesis. These defects can disrupt essential processes such as spindle assembly, cytoskeletal organization, and early cleavage dynamics, ultimately compromising embryo viability despite chromosomal normality. In addition, the follicular microenvironment, including redox balance, metabolic support, and signaling pathways, plays a crucial upstream role in maintaining translational integrity. This review integrates mechanistic evidence from molecular, cellular, and developmental studies to propose that progressive decline in translational fidelity represents a fundamental and previously underrecognized driver of reproductive aging. Understanding translational control as a central regulator of oocyte competence may provide new insights into unexplained IVF failure and support the development of novel biomarkers and therapeutic strategies aimed at preserving reproductive potential. Full article

Reproductive efficiency in cattle is critically dependent on embryo quantity and quality, particularly in assisted reproductive technology (ART) programs such as superovulation, embryo transfer, and embryo production. Nutrition is a key determinant of embryo yield through its regulatory effects on metabolic signaling, ovarian function, oocyte competence, and early embryogenesis. This review synthesizes the current evidence describing mechanistic links between nutritional status and embryo production in dairy and beef cattle across both in vivo and in vitro systems. Energy balance, protein supply, micronutrients, and fatty acids influence metabolic hormones including insulin, insulin-like growth factor-1, and leptin, which regulate hypothalamic–pituitary–gonadal axis activity, follicular recruitment, and steroidogenesis. Negative energy balance disrupts endocrine signaling, elevates circulating non-esterified fatty acids, increases oxidative stress, and impairs oocyte mitochondrial function, resulting in reduced embryo yield, compromised blastocyst quality, and diminished cryotolerance. Targeted micronutrients such as selenium, zinc, vitamins A and E, B-complex vitamins, and omega-3 fatty acids enhance antioxidant capacity, membrane integrity, and epigenetic regulation, thereby supporting embryo viability and post-transfer survival. Furthermore, early-life nutrition programs long-term reproductive capacity by influencing ovarian reserve establishment and oocyte epigenetic competence. Strategic nutritional management is therefore essential to optimize ART outcomes and promote sustainable genetic progress in cattle production systems. Full article