CReATe Fertility Centre

Background Preimplantation genetic testing for aneuploidy (PGT-A) is used principally to identify embryos with whole chromosome aneuploidy, which are generally considered non-viable. Reports of healthy live births following transfer of embryos classified as fully aneuploid are therefore extraordinary and require rigorous verification. Methods This commentary evaluates how claims of live births from embryos diagnosed as fully aneuploid by PGT-A are generated, interpreted and reported. We examine prevailing evidentiary standards and highlight key sources of potential error, including lack of genetic identity confirmation, natural conception, laboratory or clerical error and misclassification of mosaic or segmental aneuploid embryos. Results To date, no published report has included DNA-based confirmation demonstrating that a healthy child originated from an embryo diagnosed as fully aneuploid. Failure to clearly distinguish whole chromosome aneuploidy from mosaic or segmental aneuploidy, which retain the potential to result in live birth, further complicates interpretation and risks overstating the implications of such reports. Conclusion In the absence of genetic identity confirmation, claims of live births from embryos classified as fully aneuploid cannot be considered evidentiary. As interest in this topic grows, rigorous genetic validation and standardised reporting should be required to ensure scientific credibility, support accurate patient counseling and guide responsible interpretation of these reports.

BackgroundWomen are born with a limited number of eggs, which decline over time. Premature ovarian insufficiency (POI) occurs when this decline happens before age 40, causing infertility. Bone marrow (BM) stem cells may help restore ovarian function, as some women conceive after BM transplants. Studies suggest that mobilizing stem cells with Granulocyte Colony-Stimulating Factor (G-CSF) can improve ovarian response in women with diminished ovarian reserve, possibly without needing ovarian infusion. Our study aimed to evaluate if G-CSF injections alone could improve ovarian function in women with POI.MethodsThis was a pilot, non-randomized, open-label clinical trial including 11 women aged 25–40 years with clinical POI and menopausal symptoms, defined by elevated follicle-stimulating hormone (FSH) on two occasions, low anti-Müllerian hormone (AMH), and reduced antral follicle count (AFC). Participants received up to three rounds of subcutaneous G-CSF administered daily for four days per month over 60 days. Ovarian reserve markers (FSH, AMH, AFC), menstruation resumption, and menopausal symptoms were assessed at baseline and multiple follow-up points over 12 months.ResultsThe mean age of participants was 34.1 ± 5.2 years (BMI 23.96 ± 4.0 kg/m²). GCS-F injections resulted in significant increases in white blood cells and mild elevation of liver enzymes which returned to baseline within one month. By four months, significant improvements in menopausal symptoms were reported. Exploratory analyses did not identify consistent correlations between clinical response and baseline characteristics. Mean FSH decreased from 54.3 ± 24.6 IU/L at baseline to 29.0 ± 8.1 IU/L at six months (p = 0.008). AMH and AFC rose modestly (0.21 ± 0.15 to 0.49 ± 1.13 pmol/L; 1.09 ± 1.0 to 2.18 ± 2.60) but did not reach statistical significance. Menstruation resumed in 7 of 11 women (63.6%, p = 0.031). One participant showed marked response including retrieval of three mature oocytes.ConclusionsG-CSF injections were associated with menstrual resumption and symptom relief in most women with POI, suggesting biological activity. Although improvements in ovarian reserve markers were modest and disappointing in terms of the potential for assisted reproduction, these findings may support further evaluation of G-CSF in larger, controlled trials to clarify its clinical benefit and therapeutic potential.Trial registrationNCT06117982. https://clinicaltrials.gov/study/NCT06117982?cond=The%20Impact%20of%20Granulocyte%20Colony%20Stimulating%20Factor%20on%20Premature%20Ovarian%20Insufficiency&rank=1.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12958-025-01510-z.

This guideline provides evidence-based recommendations, drawn exclusively from recent randomized control trials, for the clinical management of frozen embryo transfers (FET). In Canada, the incidence of freeze-all cycles has increased from 24.0% to 78.4% over the last decade. While a freeze-all strategy can be a pivotal tool for preventing ovarian hyperstimulation syndrome, the available data do not support its routine use for improving live birth rates, reducing pregnancy loss or enhancing obstetric outcomes in the general IVF population. Similarly, ovulatory FET cycles do not offer advantages over artificial FET cycles for live birth or pregnancy loss, and current evidence remains conflicting for obstetric and perinatal outcomes. The route of progesterone administration in artificial FET cycles does not significantly affect live birth or pregnancy loss rates. FET approaches should be individualized based on patient characteristics and clinical context, and further research is necessary to optimize outcomes and inform best practices.

In briefGeneralized anxiety disorder, major depressive disorder and their treatment selective serotonin reuptake inhibitors (SSRIs) impact 4–17% of pregnancies worldwide and alter the epigenome of numerous tissues, but their effects on the ovarian follicle are unknown. This study profiles the methylome of granulosa cells, revealing novel epigenetic pathways and molecular mechanisms altered by mental health conditions and their treatments.Generalized anxiety and major depressive disorders (GAD/MDD) impact 4–17% of pregnancies worldwide. GAD/MDD and SSRIs alter the epigenome of numerous tissues; however, their effect on the ovarian follicular niche is unknown. In this study, we determined SSRI concentrations in the follicular fluid and matched patients by clinical and stimulation characteristics, and then grouped them into three groups: i) treated GAD/MDD (n = 10), ii) untreated GAD/MDD (n = 4), and iii) control (n = 10). DNA methylation sequencing was performed on granulosa cells using the Illumina TruSeq Methyl Capture EPIC kit. For patients with untreated GAD/MDD, we identified 3,829 differentially methylated sites (DMSs). Pathway analysis revealed an enrichment in genes involved in catabolism and immune response for the hypomethylated DMSs and hypermethylated DMSs were associated with protein localization and cellular transport. When assessing the effect of SSRI treatment, we identified 3,690 DMSs. Hypomethylated DMSs were associated with genes involved in cytoskeleton organization and cellular transport, whereas hypermethylated DMSs were associated with apoptosis and cell cycle. This is the first study profiling the methylome of human granulosa cells from patients with treated or untreated GAD/MDD. This study provides a valuable dataset describing the effects of SSRI on cells in the ovarian follicular niche.

Abstract Study question What molecular mechanisms trigger aneuploid cell depletion in post-implantation mosaic embryos, enabling self-correction and pregnancy success? Summary answer Aneuploid cell depletion in day 9-11 mosaic embryos is driven by disrupted stress responses, pluripotency dysregulation and impaired energy expenditure, mediated by aneuploid-euploid cell competition. What is known already Embryo aneuploidy is a major cause of adverse pregnancy outcomes. However, mosaic embryos - especially those with low-level aneuploidy (<50%), have significantly higher developmental potential, resulting in ongoing pregnancy and live birth of normal babies. Although their implantation rates are lower than euploid embryos, multicenter data from over 3,500 mosaic embryo transfers show that only 1.2% of mosaicism persists during pregnancy and postnatally, suggesting a self-correction capacity in many mosaic embryos. Despite these promising outcomes, the use of mosaic embryos in IVF remains limited due to an incomplete understanding of the biological mechanisms underlying their developmental success. Study design, size, duration Donated preimplantation euploid, aneuploid and mosaic embryos from the CReATe Fertility Centre and Zouves Fertility Center (Veritas IRB protocol #16580) were cultured from day 5-6 to day 9-11. 3870 cells from 31 post-implantation embryos (aneuploid, n = 7; mosaic, n = 8; euploid, n = 16) were included for single-cell RNA sequencing (scRNA-seq) analysis. An iPSC-based mosaic model was established by co-culturing euploid and reversine-treated (aneuploid) naive iPSCs in a transwell system for 96 hours. Participants/materials, setting, methods Cultured embryos were dissociated into single cells and pooled for scRNA-seq (10x Chromium). Sequencing results were analyzed using Freemuxlet to identify embryo-of-origin, Seurat for clustering, and InferCNV to determine post-implantation cell ploidy. Lineage developmental trajectory was inferred from pseudotime analysis. Enriched genetic markers and pathways were identified through differential expression analyses. RT-qPCR and immunofluorescence assays were used to quantify gene and protein expression in iPSC models. Main results and the role of chance scRNA-seq data from 3870 embryonic cells revealed diverse post-implantation lineages, including epiblast, hypoblast, and multiple trophoblast subtypes. Transcriptomic and regulon analysis showed aneuploid cell survival was dependent on embryonic environments. In homogenous aneuploid embryos, we observed adaptive stress responses that support temporary survival and aneuploidy tolerance. This includes delayed differentiation across all lineages, upregulation of genes related to pluripotency (e.g. KLF4) and unfolded protein response (e.g. ATF4). In contrast, mosaic embryos exhibited complex cell competition dynamics, where aneuploid cells in mosaic embryos were driven toward pluripotency exit, evidenced by advanced progression along developmental trajectory and downregulated pluripotency genes. This shift was accompanied by disrupted homeostatic pathways, including glycolysis (e.g. MYC) and proteostasis (e.g. DDIT4), leading to elevated apoptotic activity (e.g. CASP8). Our iPSC-based mosaic model recapitulated differential fitness levels in mosaic embryos. In a mosaic environment, aneuploid iPSCs exhibited impaired viability and growth, along with significant downregulation of DDIT4 (log2FC=-3.16, p < 0.05), and KLF4 (log2FC=-0.54, p < 0.05). Enhanced autophagy was observed in euploid iPSCs, indicated by accumulation of LC3 complex, while aneuploid iPSCs displayed increased apoptotic signaling, marked by elevated Caspase-8 levels. Together, Our results pointed to a diminished survival advantage in the aneuploid cells of mosaic embryos, driving their selective depletion. Limitations, reasons for caution We compared the transcriptomic signatures of aneuploid cells in aneuploid and mosaic embryos. Expanding the sample size will improve generalizability of the findings. Furthermore, while the iPSC-based mosaic model mirrors key aspects of the mosaic environment, it may not fully recapitulate the complexity of in vivo embryonic development. Wider implications of the findings Our study unravels molecular mechanisms contributing to self-correction and pregnancy success of mosaic embryos. These results provide the foundation for interrogating developmental competence of mosaic embryos, potentially expanding the range of viable embryos suitable for IVF treatment and improving options for fertility preservation. Trial registration number No

Aneuploidy accounts for many pregnancy failures and congenital anomalies. Preimplantation genetic testing for aneuploidy (PGT-A) is a screening test applied to embryos created from in vitro fertilization to diminish the chance of an aneuploid conception. The rate of misdiagnosis for both false aneuploidy (false positive) and false euploidy (false negative) test results is unknown. The objective of this study was to determine the rate of misclassification of both aneuploidy and euploidy after PGT-A. We conducted a systematic review and meta-analysis. We searched Medline, Embase, Cochrane Central, CINAHL and WHO Clinical Trials Registry from inception until April 10, 2024. The protocol was registered in International Prospective Register of Systematic Reviews (PROSPERO CRD 42020219074). We included studies that conducted either a pre-clinical validation of the genetic platform for PGT-A using a cell line, studies that compared the embryo biopsy results to those from the whole dissected embryo or its inner cell mass (WE/ICM), and studies that compared the biopsy results to prenatal or postnatal genetic testing. Two independent reviewers extracted true and false positives and negatives comparing biopsy results to the reference standard (known karyotype, WE/ICM, pregnancy outcome). For preclinical studies, the main outcome was the positive and negative predictive values. Misdiagnosis rate was the outcome for pregnancy outcome studies. The electronic search yielded 6674 citations, of which 109 were included. For WE/ICM studies (n=40), PPV was 89.2% (95% CI 83.1-94.0) and NPV was 94.2% (95% CI 91.1-96.7, I2=42%) for aneuploid and euploid embryos, respectively. The PPV for mosaic embryos of either a confirmatory mosaic or aneuploid result was 52.8% (95% CI 37.9-67.5). For pregnancy outcome studies (n=43), the misdiagnosis rate after euploid embryo transfer was 0.2% (95% CI 0.0-0.7%, I2=65%). However, the rate for mosaic transfer, with a confirmatory euploid pregnancy outcome, was 21.7% (95% CI: 9.6-36.9, I2=95%). The accuracy of an aneuploid result from PGT-A is excellent and can be relied upon as a screening tool for embryos to avoid aneuploid pregnancies. Similarly, the misdiagnosis rate after euploid embryo transfer is less than 1%. However, there is a significant limitation in the accuracy of mosaic embryos.