Developmental 6:2 FTCA exposure impairs renal development in chicken embryos via IGF signaling.

6:2 fluorotelomer carboxylic acid (6:2 FTCA) is a perfluorooctanoic acid (PFOA) substitute, which is supposedly less accumulative and toxic than PFOA. However, 6:2 FTCA is structurally similar to PFOA, and there had already been reports about its toxicities comparable to PFOA. The aim of the current study is to assess potential effects of developmental exposure to 6:2 FTCA on the development of kidney in chicken embryo and to investigate underlying mechanism. Fertile chicken eggs were exposed to 1.25 mg/kg, 2.5 mg/kg or 5 mg/kg doses of 6:2 FTCA, or 2 mg/kg PFOA, then incubated to hatch. Serum and kidney of hatchling chickens were collected. Blood urea nitrogen (BUN) and creatinine (Cre) levels were measured with commercially available kits. Morphology of kidney was assessed with histopathology. To further reveal molecular mechanism of observed endpoints, IGF signaling molecules were assessed in the kidney samples with qRT-PCR, results indicated that IGFBP3 is a potentially crucial molecule. Lentiviruses overexpressing or silencing IGFBP3 were designed and applied to enhance/suppress the expression of IGFBP3 in developing chicken embryo for further verification of its role in the observed effects. Disrupted nephron formation, in the manifestation of decreased glomeruli number/area and increased serum BUN/Cre levels, was observed in the animals developmentally exposed to 6:2 FTCA. Correspondingly, IGF signaling molecules (IGF1, IGF1R and IGFBP3) were affected by 6:2 FTCA exposure. Meanwhile, overexpression of IGFBP3 effectively alleviated such changes, while silencing of IGFBP3 mimicked observed effects. In conclusion, developmental exposure to 6:2 FTCA is associated with disrupted chicken embryo renal development, in which IGFBP3 seems to be a remarkable contributor, suggesting potential health risks for human and other species. Further risk assessments and mechanistic works are necessary.

The timing of pronuclear transfer critically affects the developmental competence and quality of embryos.

Pronuclear transfer has been successfully used in human assisted reproduction to suppress the adverse effects of a defective oocyte cytoplasm or to bypass an idiopathic developmental arrest. However, the effects of the initial parental genome remodelling in a defective cytoplasm on the subsequent development after pronucleus transfer have not been systematically studied. By performing pronuclear transfer in pre-replication and post-replication mouse embryos, we show that the timing of the procedure plays a critical role. Although apparently morphologically normal blastocysts were obtained in both pre- and post-replication pronuclear transfer groups, post-replication pronuclear transfer led to a decrease in developmental competence and profound changes in embryonic gene expression. By inhibiting the replication in the abnormal cytoplasm before pronuclear transfer into a healthy cytoplasm, the developmental potential of embryos could be largely be restored. This shows that the conditions under which the first embryonic replication occurs strongly influence developmental potential. Although pronuclear transfer is the method of choice for mitigating the impact of a faulty oocyte cytoplasm on early development, our results show that the timing of this intervention should be restricted to the pre-replication phase.

Lactate modulates zygotic genome activation through H3K18 lactylation rather than H3K27 acetylation.

In spite of its essential role in culture media, the precise influence of lactate on early mouse embryonic development remains elusive. Previous studies have implicated lactate accumulation in medium affecting histone acetylation. Recent research has underscored lactate-derived histone lactylation as a novel epigenetic modification in diverse cellular processes and diseases. Our investigation demonstrated that the absence of sodium lactate in the medium resulted in a pronounced 2-cell arrest at the late G2 phase in embryos. RNA-seq analysis revealed that the absence of sodium lactate significantly impaired the maternal-to-zygotic transition (MZT), particularly in zygotic gene activation (ZGA). Investigations were conducted employing Cut&Tag assays targeting the well-studied histone acetylation and lactylation sites, H3K18la and H3K27ac, respectively. The findings revealed a noticeable reduction in H3K18la modification under lactate deficiency, and this alteration showed a significant correlation with changes in gene expression. In contrast, H3K27ac exhibited minimal correlation. These results suggest that lactate may preferentially influence early embryonic development through H3K18la rather than H3K27ac modifications.

Different endometrial preparation protocols on first frozen-thawed embryo transfer outcomes after hysteroscopic polypectomy: A retrospective cohort study.

OBJECTIVE: To evaluate the optimal endometrial preparation protocol for frozen-thawed embryo transfer (FET) following hysteroscopic polypectomy. METHODS: This was a retrospective clinical cohort study involving 464 patients who underwent their first FET after polyp resection between January 2021 and July 2023. The cohorts were categorized into three groups: the natural cycle (NC) group (n = 139), the ovarian induction (OI) group (n = 117), and the hormone replacement therapy (HRT) group (n = 208). RESULTS: In the initial unadjusted analysis, both NC and OI cycles exhibited similar pregnancy rates but were associated with significantly higher implantation rate (56.5%, 57.1% vs 42.0%, P < 0.001), clinical pregnancy rate (73.4%, 74.4% vs 57.2%, P = 0.001), and ongoing pregnancy rate (OPR; 67.6%, 63.2% vs 51.0%, P = 0.005) compared to the HRT group. Additionally, the three groups demonstrated comparable abortion rate (7.8%, 14.9% vs 10.9%, P = 0.299). After adjusting for potential confounders in the multiple logistic regression model, the HRT protocol resulted in a 54% significantly lower OPR compared to the NC protocol (adjusted odds ratio [aOR] = 0.46, 95% confidence interval [CI]: 0.28-0.77; P = 0.003). Meanwhile, the OPR difference between the OI protocol and the NC protocol remained insignificant (OI vs NC: aOR = 0.62, 95% CI: 0.35-1.12; P = 0.112). CONCLUSION: The ovulatory-FET scheme (NC and OI) following hysteroscopic polyp resection displayed promising clinical outcomes compared with HRT-FET scheme. The regimen without exogenous estrogen administration should be prioritized for endometrial preparation protocol after polypectomy.

Research trends of Moringa oleifera Lam as Remedy toward Cattle's embryo according to the frequently used words in content of papers and citations.

Moringa oleifera is an herb that has the potential to reduce the mortality rate of an embryo. Research about Moringa oleifera treatment toward an embryo of livestock was quite a number. However, there were still very few previous studies that explain the trend of research related to that topic in this decade, 2010-2023. This study tried to observe the research trend related to Moringa oleifera treatment to embryos of livestock in terms of frequently used words inside papers along with their citations. This study gathered 132 data samples from Scopus and 41 data from PubMed and processed them using the bibliometric method. The bibliometric software used was Vosviewer to produce the image of the author's keyword connection and trend and biblioshiny for depicting frequently words used as a title and inside content and mean of total citation/year. This study also used R Studio to complement Vosviewer in conducting the bibliometric method. The result showed that there was no author's keyword that depicted ruminant-type animals instead of cow, and no name of the animal as livestock that was being used as a title of the sample papers. There were also no papers that observed Moringa oleifera to treat sick embryos of livestock and the previous studies used as samples also had a low mean of total citation/year.

Vitamin D levels in couples undergoing In vitro Fertilization: Lack of Association with Embryo Quality or Pregnancy Rates.

OBJECTIVE: To investigate the potential impact of vitamin D serum levels of couples going through in vitro fertilization in terms of embryo quality and pregnancy rates. DESIGN: Retrospective cohort study SETTING: Fertipraxis, private human reproduction center on Rio de Janeiro, Brazil. SUBJECTS: 267 couples who underwent intracytoplasmic sperm injection between January 2017 and March 2019. EXPOSURE: The couples were categorized into four groups based on 25OH vitamin D levels measured at the beginning of the stimulation protocol: Group 1 with levels ≥ 30 ng/mL for both women and men; Group 2 with levels < 30 ng/mL for both; Group 3 with women < 30 ng/mL and men ≥ 30 ng/mL; and Group 4 with women ≥ 30 ng/mL and men < 30 ng/mL. MAIN OUTCOME MEASURES: We consider quantity and quality of embryos during the cleavage and blastocyst stages as primary outcomes. Correspondingly, clinical pregnancy rate was regarded as a secondary outcome. RESULTS: Our findings revealed no significant correlations between the studied VD groups and the evaluated outcomes. This includes quantity and quality of embryos during the cleavage and blastocyst stages, as well as clinical pregnancy rate. Primary analysis revealed a small but statistically significant difference in the duration of controlled ovarian stimulation between group 1 and group 2 (p=0.035; CI=0.07 - 3.04) and between group 1 and group 3 (p=0.040; CI=0.05 - 3.23). CONCLUSION: The present study found no correlation between the studied VD levels and quantity and quality of cleavage or blastocyst stage embryos, nor did it show any impact on clinical pregnancy rates. Further well designed, prospective studies are warranted to determine whether and how vitamin D affects reproductive outcomes.

Controlled ovarian stimulation leads to cardiovascular changes in patients undergoing in vitro fertilization.

OBJECTIVE: To study hemodynamic changes along controlled ovarian stimulation in women undergoing in vitro fertilization. STUDY DESIGN: Prospective observational cohort study conducted at Mother and Child Department of University Hospital Federico II, in Naples, Italy, between April 2021 and July 2022. Sixty-eight infertile patients undergoing controlled ovarian stimulation with gonadotropin, antagonist protocol and a fresh embryo transfer were included. Haemodynamic assessment was carried out using UltraSonic Cardiac Output Monitor at baseline (T1), estradiol peak (T2), fresh embryo-transfer day (T3). To evaluate relationships between quantitative variables and groups a Student T test for independent data was assessed. One-way analysis of variance (ANOVA) was used to determine the differences between the means of three time points (T1, T2 and T3) for quantitative variables. A mixed-model analysis of variance (ANOVA) was used to determine the differences between groups, among time points (T1, T2 and T3). RESULTS: Sixty-eight patients were included. Significant differences over the three time points have been observed for CO (f = 3.78 l/min; p = 0.025), SVI (f = 3.56 ml/m2;p = 0.013), and RSVI (f = 4.84 dscm-5 m2; p = 0.009). No significant differences in trends have been found between beta hCG positive and beta hCG negative groups. There were no significant differences in maternal hemodynamic parameters at time-point T3 between patients treated with hCG 10,000 UI and with Triptorelin. Patients considered at increased risk of hyperstimulation reported a significant increase in SVI at baseline (26.9 ± 9.0 mL/m2 vs 21.9 ± 7.0 mL/m2; p = 0.010). CONCLUSION: According to the results of our study, during controlled ovarian stimulation with antagonist protocol, patients undergo significant changes in maternal cardiovascular parameters over a very short period.

Involvement of METTL3-mediated m6A methylation in the early development of porcine cloned embryos.

METTL3-mediated N6-methyladenosine (m6A) modification is critical for gametogenesis and early embryonic development. However, the function of METTL3-mediated m6A modification in the early development of somatic nuclear transfer embryos (SCNT) remains unclear. Here, we found that METTL3 mRNA and protein levels exhibit dynamic changes during the early development of porcine SCNT embryos. The levels of METTL3 mRNA and protein in SCNT embryos at specific developmental stages differ from those in parthenogenetic activation (PA) counterparts. SiRNA injection effectively reduced the levels of METTL3 mRNA and protein in 4-cell embryos and blastocysts. METTL3 knockdown significantly reduced the cleavage and blastocyst rates of SCNT embryos. METTL3 knockdown significantly reduced the number of total cells and trophectoderm (TE) cells in the resulting blastocysts and perturbed cell lineage allocation. In addition, METTL3 knockdown reduced the levels of m6A modification in 4-cell embryos and blastocysts. Importantly, METTL3 knockdown decreased the expression levels of CDX2, GATA3, NANOG and YAP, and increased the expression levels of SOX2 and OCT4. Taken together, these results demonstrate that METTL3-mediated m6A modification regulates early development and lineage differentiation of porcine SCNT embryos.

Mediterranean diet improves blastocyst formation in women previously infected COVID-19: a prospective cohort study.

Objectives: Our study tries to investigate the effect of the Mediterranean diet (MeDiet) on assisted reproductive treatment outcomes in women after COVID-19 infection. Design: A prospective observational cohort study in the Reproductive and Genetic Hospital of CITIC-Xiangya from February 2023 to August 2023.Subjects: A total of 605 participants previously infected with COVID-19 were enrolled. Exposure: None. Main outcome measurement: The primary outcomes are oocyte and embryo quality. The secondary outcomes are pregnancy outcomes. Results: A majority of participants (n = 517) followed low to moderate MeDiet, and only a small group of them (n = 88) followed high MeDiet. The blastocyst formation rate is significantly higher in MeDiet scored 8-14 points women (46.08%), compared to the other two groups (which is 41.75% in the low adherence population and 40.07% in the moderate adherence population respectively) (p = 0.044). However, the follicle number on hCG day, yield oocytes, normal fertilized zygotes, fertilization rate, day three embryos (cleavage embryos), and embryo quality are comparable among the three groups. For those who received embryo transfer, we noticed an obvious trend that with the higher MeDiet score, the higher clinical pregnancy rate (62.37% vs. 76.09% vs. 81.25%, p = 0.197), implantation rate (55.84% vs. 66.44% vs. 69.23%, p = 0.240) and ongoing pregnancy rate (61.22% vs. 75.00% vs. 81.25%, p = 0.152) even though the p values are not significant. An enlarging sample size study, especially in a high adherence population should be designed to further verify the effects of MeDiet's role in improving IVF performance. Conclusion: High adherence to MeDiet is associated with improved blastocyst formation in women after COVID-19 infection. There is also a trend that high adherence to MeDiet might be beneficial to clinical pregnancy, embryo implantation as well as ongoing pregnancy in these women.

A retrospective analysis of conception per embryo transfer in dairy cattle in South Korea.

The bovine embryo production industry has seen significant growth over the past two decades, particularly in the production of in vitro produced embryos. This growth, driven by advancements in cryopreservation, in vitro culture mediums, ovum pick-up (OPU) procedures, ultrasonography devices, and embryo transfer (ET) has been notable. Particularly, ET is crucial for disseminating high genetic merit and amplifying foreign breeds by importing frozen embryos. This retrospective study aimed to assess factors affecting conception per embryo transfer (CPET) in Holstein-Friesian cattle in South Korea from October 2008 to July 2022. We evaluated type of embryo breed, type of embryo production (fresh and frozen; in vitro and in vivo production), recipient conditions including estrus type, corpus luteum quality, parity (nulliparous heifers, primiparous, and multiparous cows), and the daily mean temperature-humidity index (THI) as an index for heat stress. Type of embryo breed and estrus had no significant impact on CPET. However, we observed higher CPET in recipients with good quality corpus luteum, nulliparous heifers, and surrogates receiving fresh in vitro and frozen in vivo embryos. Importantly, CPET was not adversely affected by mild heat stress conditions (up to daily mean THI 76), indicating that using frozen in vivo embryos produced by multiple ovulation embryo transfer and fresh in vitro embryos by OPU-ET can help alleviate the subfertility issues in dairy cattle caused by global warming in Korea.

Formation of the first plane of division relative to the pronuclear axis predicts embryonic ploidy.

RESEARCH QUESTION: Is there a relationship between the pronuclear axis and the first cleavage plane formation in human pronuclear-stage embryos, and what are the effects on ploidy and clinical pregnancy rates? DESIGN: Transferred embryos were followed up until their prognoses. A total of 762 embryos formed two cells and reached the blastocyst stage after normal fertilization in a time-lapse incubator. Embryos were classified into three groups: group A: embryos in which the first plane of division was formed parallel to the axis of the pronucleus; group B: embryos in which cases of oblique formation were observed; and group C: embryos in which cases of perpendicular formation were observed. RESULTS: The euploidy rate was significantly higher in groups A and B than those in group C (P < 0.01), whereas the aneuploidy rate was significantly higher in group C (P < 0.01) than in groups A and B. No differences were found between the three groups in frequency of positive HCG-based pregnancy tests, frequency of clinical pregnancies, miscarriage rates or delivery rates. CONCLUSIONS: The formation pattern of the first plane of division relative to the pronuclear axis was a predictor of embryonic ploidy, with a reduced rate of euploidy and a high probability of aneuploidy observed when the first plane of division was perpendicular to the pronuclear axis.

Characterization of conception rate after embryo transfer in comparison with that after artificial insemination in dairy cattle.

Artificial insemination (AI) and embryo transfer (ET) are important in the reproduction of dairy cows. The conception rate after AI or ET is an essential indicator when selecting appropriate breeding methods. However, information on the environmental factors affecting ET conception rate when compared with AI is limited. We aimed to investigate environmental factors affecting ET conception rate and characterize the differences in environmental factors between AI and ET. Records of the first AI (n = 1,870,143) and ET (n = 29,922) from Holstein nulliparous, primiparous, and multiparous cows in Hokkaido, Japan, were analyzed using separate multivariable logistic regression models. For each breeding method, we grouped primiparous and multiparous cows according to milk yield at peak lactation (PY; < 25, 25-30, 30-35, ≥ 35 kg in primiparous, < 40, 40-45, 45-50, ≥ 50 kg in multiparous) and the interval from calving to first AI or ET (CFI/CFT; < 60, 60-79, 80-99, ≥ 100 d) to evaluate the effects of PY and CFI/CFT on conception rate. AI conception rate decreased with increasing PY in primiparous and multiparous cows, whereas ET conception rate did not decrease significantly. Additionally, the ET conception rate did not decrease even in primiparous and multiparous cows slightly earlier than 60 d in CFI/CFT when compared with those in CFI/CFT after 60 d, which differed from the AI conception rate. Collectively, breeding by ET leads to the avoidance of negative effects of high milk yield and calving on the conception rate, indicating that cows are fertile by ET within 60 d after calving.

[Analysis of Reproductive Tract Microecological Changes During the Frozen-Thawed Embryo Transfer Cycle and Clinical Pregnancy Outcomes]. / æ¿€ç´ æ›¿ä»£å†»èƒšç§»æ¤å‘¨æœŸç”Ÿæ®–é“å¾®ç”Ÿæ€å˜åŒ–ä¸Žå¦Šå¨ ç»“å±€åˆ†æž.

Objective: This study aims to analyze the relationship between reproductive tract microecological changes, metabolic differences, and pregnancy outcomes at different time points in the frozen-thawed embryo transfer cycle while patients are undergoing hormone replacement therapy, which will be a breakthrough point for improving outcomes. Methods: A total of 20 women undergoing frozen-thawed single blastocyst transfer for the first time at the Reproductive Medicine Center of Fujian Maternal and Child Health Hospital between July 2022 and January 2023 were recruited for this study. Their vaginal and cervical secretions were collected for 16S rRNA sequencing and non-targeted metabolomics analysis on days 2-5 of menstruation, day 7 after estrogen replacement therapy started, the day when progesterone was added, and the day of transplantation. The subjects were divided into different groups according to their clinical pregnancy status and the sequencing results were analyzed using bioinformatics methods. Results: 1) The alpha-diversity index of the vaginal and cervical microbiota was higher on days 2-5 of menstruation (P<0.01), but did not differ significantly on day 7 after oral estrogen replacement therapy started, the day of progesterone administration, and the day of transplantation (P≥0.1). 2) Both the pregnant group and the non-pregnant group showed a variety of microorganisms and metabolites with significant differences in the lower reproductive tract at different time points. 3) Microbial analysis at different time points showed that there were significant differences in vaginal flora, including Peptoniphilus, Enterocloster, Finegoldia, Klebsiella, Anaerobutyricum, Agathobaculum, Sporanaerobacter, Bilophila, Prevotella, and Anaerococcus in the pregnant group (P<0.05). 4) Metabolite analysis at different time points showed that there were significant differences in 3-hydroxybenzoic acid, linatine, (R)-amphetamine, hydroxychloroquine, and L-altarate in the vaginal secretions of the pregnant group (P<0.05), and that there were significant differences in isocitric acid, quassin, citrinin, and 12(R)-HETE in the cervical secretions (P<0.05). 5) Metabolite analysis at different time points showed that, in the non-pregnant group, there were significant differences in linatine, decanoyl-L-carnitine, aspartame, sphingosine, and hydroxychloroquine in the vaginal secretions (P<0.05), and the isocitric acid, quassin, ctrinin, and 12(R)-HETE in the cervical secretions (P<0.05). 6) Combined microbiome and metabolomics analysis showed that certain metabolites were significantly associated with microbial communities, especially Klebsiella. Conclusions: Significant differences in the microbiota genera and metabolites at different time points were found during the frozen-embryo transfer cycle of hormone replacement therapy, which may be used as potential biomarkers to predict pregnancy outcomes of embryo transfer.

Impaired embryo development potential associated with thyroid autoimmunity in euthyroid infertile women with diminished ovarian reserve.

Purpose: The aim of this study was to evaluate the associations of thyroid autoimmunity (TAI) with the number of oocytes retrieved (NOR), fertilization rate (FR), and embryo quality (EQ) in euthyroid women with infertility and diminished ovarian reserve (DOR). Methods: This retrospective cohort study involved 1,172 euthyroid women aged 20-40 years with infertility and DOR who underwent an oocyte retrieval cycle. TAI was diagnosed in the presence of serum thyroperoxidase antibody (TPOAb) concentrations higher than 34 IU/ml and/or serum thyroglobulin antibody (TgAb) concentrations exceeding 115.0 IU/ml. Among these women, 147 patients with TAI were classified as the TAI-positive group, while 1,025 patients without TAI were classified as the TAI-negative group. Using generalized linear models (GLMs) adjusted for confounding factors, we evaluated the associations of TAI and the serum TPOAb and TgAb concentrations and NOR, FR, and EQ in this study's subjects. The TPOAb and TGAb values were subjected to log10 transformation to reduce skewness. Logistic regression models were used to estimate the effects of TPOAb and TgAb concentrations on the probabilities of achieving a high NOR (≥7) and high FR (>60%). Results: For the whole study population, women with TAI had a significantly lower NOR and poorer EQ than women without TAI (P < 0.001 for both). Interestingly, in the TSH ≤2.5 subgroup, the TAI-positive group also had a significantly lower NOR and poorer EQ than the TAI-negative group (P < 0.001 for both). Furthermore, negative associations were observed between log10(TPOAb) concentrations and NOR and the number of high-quality embryos and available embryos (P < 0.05 for all). The log10(TgAb) concentrations were inversely associated with NOR and the number of high-quality embryos (P < 0.05 for all). In the regression analysis, the log10(TPOAb) concentrations had lower probabilities of achieving a high NOR [adjusted odds ratio (aOR): 0.56; 95% confidence interval (95% CI) 0.37, 0.85; P = 0.007]. Conclusions: TAI and higher TPOAb and TgAb concentrations were shown to be associated with reductions in the NOR and EQ in the study population. Our findings provide further evidence to support systematic screening and treatment for TAI in euthyroid women with infertility and DOR.

Mapping of long interspersed element-1 (L1) insertions by TIPseq provides information about sub chromosomal genetic variation in human embryos.

PURPOSE: Retrotransposons play important roles during early development when they are transiently de-repressed during epigenetic reprogramming. Long interspersed element-1 (L1), the only autonomous retrotransposon in humans, comprises 17% of the human genome. We applied the Single Cell Transposon Insertion Profiling by Sequencing (scTIPseq) to characterize and map L1 insertions in human embryos. METHODS: Sixteen cryopreserved, genetically tested, human blastocysts, were accessed from consenting couples undergoing IVF at NYU Langone Fertility Center. Additionally, four trios (father, mother, and embryos) were also evaluated. scTIPseq was applied to map L1 insertions in all samples, using L1 locations reported in the 1000 Genomes as controls. RESULTS: Twenty-nine unknown and unique insertions were observed in the sixteen embryos. Most were intergenic; no insertions were located in exons or immediately upstream of genes. The location or number of unknown insertions did not differ between euploid and aneuploid embryos, suggesting they are not merely markers of aneuploidy. Rather, scTIPseq provides novel information about sub-chromosomal structural variation in human embryos. Trio analyses showed a parental origin of all L1 insertions in embryos. CONCLUSION: Several studies have measured L1 expression at different stages of development in mice, but this study for the first time reports unknown insertions in human embryos that were inherited from one parent, confirming no de novo L1 insertions occurred in parental germline or during embryogenesis. Since one-third of euploid embryo transfers fail, future studies would be useful for understanding whether these sub-chromosomal genetic variants or de novo L1 insertions affect embryo developmental potential.

Immobilized NRG1 Accelerates Neural Crest like Cell Differentiation Toward Functional Schwann Cells Through Sustained Erk1/2 Activation and YAP/TAZ Nuclear Translocation.

Neural Crest cells (NC) are a multipotent cell population that give rise to a multitude of cell types including Schwann cells (SC) in the peripheral nervous system (PNS). Immature SC interact with neuronal axons via the neuregulin 1 (NRG1) ligand present on the neuronal surface and ultimately form the myelin sheath. Multiple attempts to derive functional SC from pluripotent stem cells have met challenges with respect to expression of mature markers and axonal sorting. Here, they hypothesized that sustained signaling from immobilized NRG1 (iNRG1) might enhance the differentiation of NC derived from glabrous neonatal epidermis towards a SC phenotype. Using this strategy, NC derived SC expressed mature markers to similar levels as compared to explanted rat sciatic SC. Signaling studies revealed that sustained NRG1 signaling led to yes-associated protein 1 (YAP) activation and nuclear translocation. Furthermore, NC derived SC on iNRG1 exhibited mature SC function as they aligned with rat dorsal root ganglia (DRG) neurons in an in vitro coculture model; and most notably, aligned on neuronal axons upon implantation in a chick embryo model in vivo. Taken together their work demonstrated the importance of signaling dynamics in SC differentiation, aiming towards development of drug testing platforms for de-myelinating disorders.

Vitrification preservation of good-quality blastocysts for more than 5 years reduces implantation and live birth rates.

STUDY QUESTION: Does vitrification cryopreservation of embryos for more than 5 years affect the pregnancy outcomes after frozen embryo transfer (FET)? SUMMARY ANSWER: Vitrification cryopreservation of good-quality blastocysts for more than 5 years is associated with a decrease in the implantation rate (IR) and live birth rate (LBR). WHAT IS KNOWN ALREADY: Previous studies have predominantly focused on embryos cryopreserved for relatively short durations (less than 5 years), yet the impact of extended cryopreservation duration on pregnancy outcomes remains a controversial issue. There is a relative scarcity of data regarding the efficacy and safety of storing embryos for 5 years or longer. STUDY DESIGN, SIZE, DURATION: This retrospective study involved 36 665 eligible vitrified-thawed embryo transfer cycles from 1 January 2016 to 31 December 2022, at a single fertility center in China. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients were divided into three groups according to embryo storage time: Group 1 consisted of 31 565 cycles, with storage time of 0-2 years; Group 2 consisted of 4458 cycles, with a storage time of 2-5 years; and Group 3 included 642 cycles, with storage time exceeding 5 years. The main outcome measures were IR and LBR. Secondary outcome variables included rates of biochemical pregnancy, multiple pregnancy, ectopic pregnancy, and miscarriage, as well as neonatal outcomes. Reproductive outcomes were analyzed as binary variables. Multivariate logistic regression analysis was used to explore the effect of preservation time on pregnancy outcomes after correcting for confounding factors. In addition, we also assessed neonatal outcomes, such as large for gestational age (LGA) and small for gestational age (SGA). MAIN RESULTS AND THE ROLE OF CHANCE: IRs in the three groups (0-2, 2-5, and >5 years) were 37.37%, 39.03%, and 35.78%, respectively (P = 0.017), and LBRs in the three groups were 37.29%, 39.09%, and 34.91%, respectively (P = 0.028). After adjustment for potential confounding factors, compared with the 0-2 years storage group, prolonged embryo vitrification preservation time (2-5 years or >5 years) did not affect secondary outcomes such as rates of biochemical pregnancy, multiple pregnancy, ectopic pregnancy, and miscarriage (P > 0.05). But cryopreservation of embryos for more than 5 years reduced the IR (adjusted odds ratio (aOR) 0.82, 95% CI 0.69-0.97, P = 0.020) and LBR (aOR 0.76, 95% CI 0.64-0.91, P = 0.002). Multivariate stratified analysis also showed that prolonging the cryopreservation time of blastocysts (>5 years) reduced the IR (aOR 0.78, 95% CI 0.62-0.98, P = 0.033) and LBR (aOR 0.68, 95% CI 0.53-0.87, P = 0.002). However, no effect on cleavage embryos was observed (P > 0.05). We further conducted stratified analyses based on the number and quality of frozen blastocysts transferred, and the results showed that the FET results after transfers of good-quality blastocysts in the >5 years storage group were negatively affected. However, the storage time of non-good-quality blastocysts was not significantly associated with pregnancy outcomes. Regarding the neonatal outcomes (of singletons), embryo vitrification preservation time had no effect on preterm birth rates, fetal birth weight, or neonatal sex ratios. However, as the storage time increased, rates of SGA (5.60%, 4.10%, and 1.18%) decreased, while rates of LGA (5.22%, 6.75%, and 9.47%) increased (P < 0.05). After adjusting for confounding factors, the increase in LGA and the decrease in SGA were significantly correlated with the duration of storage time. LIMITATIONS, REASONS FOR CAUTION: This was a retrospective study using data from a single fertility center, even though the data had been adjusted, our findings still need to be validated in further studies. WIDER IMPLICATIONS OF THE FINDINGS: With the full implementation of the two-child policy in China, there may be more patients whose embryos have been frozen for a longer time in the future. Patients should be aware that the IR and LBR of blastocysts are negatively affected when the cryopreservation time is longer than 5 years. Couples may therefore consider shortening the time until FET treatment. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Nature Science Foundation of China (No. 82101672), Science and Technology Projects in Guangzhou (No. 2024A03J0180), General Guidance Program for Western Medicine of Guangzhou Municipal Health Commission (No. 20231A011096), and the Medical Key Discipline of Guangzhou (2021-2023). None of the authors have any conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Beyond black-box models: explainable AI for embryo ploidy prediction and patient-centric consultation.

PURPOSE: To determine if an explainable artificial intelligence (XAI) model enhances the accuracy and transparency of predicting embryo ploidy status based on embryonic characteristics and clinical data. METHODS: This retrospective study utilized a dataset of 1908 blastocyst embryos. The dataset includes ploidy status, morphokinetic features, morphology grades, and 11 clinical variables. Six machine learning (ML) models including Random Forest (RF), Linear Discriminant Analysis (LDA), Logistic Regression (LR), Support Vector Machine (SVM), AdaBoost (ADA), and Light Gradient-Boosting Machine (LGBM) were trained to predict ploidy status probabilities across three distinct datasets: high-grade embryos (HGE, n = 1107), low-grade embryos (LGE, n = 364), and all-grade embryos (AGE, n = 1471). The model's performance was interpreted using XAI, including SHapley Additive exPlanations (SHAP) and Local Interpretable Model-agnostic Explanations (LIME) techniques. RESULTS: The mean maternal age was 38.5 ± 3.85 years. The Random Forest (RF) model exhibited superior performance compared to the other five ML models, achieving an accuracy of 0.749 and an AUC of 0.808 for AGE. In the external test set, the RF model achieved an accuracy of 0.714 and an AUC of 0.750 (95% CI, 0.702-0.796). SHAP's feature impact analysis highlighted that maternal age, paternal age, time to blastocyst (tB), and day 5 morphology grade significantly impacted the predictive model. In addition, LIME offered specific case-ploidy prediction probabilities, revealing the model's assigned values for each variable within a finite range. CONCLUSION: The model highlights the potential of using XAI algorithms to enhance ploidy prediction, optimize embryo selection as patient-centric consultation, and provides reliability and transparent insights into the decision-making process.

Non-invasive preimplantation genetic testing for aneuploidy: is the promise real?

Recent advances in preimplantation genetic testing for aneuploidy (PGT-A) have significantly enhanced its application in ART, providing critical insights into embryo viability, and potentially reducing both the time spent in fertility treatments and the risk of pregnancy loss. With the integration of next-generation sequencing, PGT-A now offers greater diagnostic precision, although challenges related to segmental aneuploidies and mosaicism remain. The emergence of non-invasive PGT-A (niPGT-A), which analyzes DNA in spent embryo culture media, promises a simpler aneuploidy screening method. This mini review assesses the methodological criteria for test validation, the current landscape of PGT-A, and the potential of niPGT-A, while evaluating its advantages and potential pitfalls. It underscores the importance of a robust three-phase validation process to ensure the clinical reliability of PGT-A. Despite initial encouraging data, niPGT-A not only confronts issues of DNA amplification failure and diagnostic inaccuracies but also has yet to meet the three-prong criteria required for appropriate test validation, necessitating further research for its clinical adoption. The review underscores that niPGT-A, like traditional PGT-A, must attain the high standards of precision and reliability expected of any genetic testing platform used in clinical settings before it can be adopted into routine ART protocols.

Effects of high-normal fasting blood glucose on ART outcomes of frozen-thawed single blastocyst transfer in women with normal BMI.

PURPOSE: This retrospective cohort study aims to investigate whether high-normal fasting blood glucose (FBG) affects assisted reproductive technology (ART) outcomes undergoing single blastocyst frozen-thawed embryo transfer (FET) cycles in women with normal body mass index (BMI). METHODS: 944 women with normal BMI and FBG levels undergoing single blastocyst FET cycles were enrolled. Based on the median of FBG (4.97 mmol/L, 1 mmol/L = 18 mg/dL), the subjects were categorized into the low-normal group (3.90 ≤ FBG ≤ 4.97 mmol/L, n = 472) and the high-normal group (4.97 < FBG < 6.10 mmol/L, n = 472). Multivariable logistic regression and receiver operating characteristic (ROC) were used to analyze the relationship between high-normal FBG and ART outcomes. PRIMARY OUTCOME: live birth rate (LBR). RESULTS: LBR was significantly lower in the high-normal group than in the low-normal group (36.8% vs. 45.1%, p = 0.010), and the miscarriage rate was considerably higher than that in the low-normal group (23.9% vs. 16.5%, p = 0.041). High-normal FBG of female was an independent predictor of live birth (adjusted OR:0.747, 95% CI: 0.541-0.963, p = 0.027) and miscarriage (adjusted OR:1.610, 95% CI: 1.018-2.547, p = 0.042). ROC analyses showed that the cut-off values of FBG (endpoints: live birth and miscarriage) were 5.07 mmol/L, and 5.01 mmol/L, respectively. CONCLUSIONS: In women with normal BMI, high-normal FBG is an independent risk factor for lower LBR and higher miscarriage rate in single blastocyst FET cycles. Attention to preconception FBG monitoring in this particular population may allow early intervention to improve ART outcomes.