Journal of Assisted Reproduction and Genetics最新文献

Background: Whether a mosaic blastocyst involving two chromosomes, each with a 45% mosaic level, can self-correct to a chromosomally normal and healthy individual post-implantation remains largely unexplored in the literature.

Methods: A 35-year-old woman with unexplained infertility underwent in vitro fertilization (IVF) treatment. After multiple failed implantation attempts, one euploid female blastocyst and one mosaic male blastocyst (monosomy 11 (45%) and segmental monosomy 18 (45%) with a terminal segmental trisomy 18) were concurrently transferred in her final cycle.

Results: Of the two transferred blastocysts, only one successfully implanted. The pregnancy progressed uneventfully. Amniocentesis revealed a male fetus, indicating that the implanted blastocyst was the mosaic one. Reports of karyotype and array CGH of amniotic fluid revealed no abnormality. The patient delivered a healthy male infant at 37 + 5 weeks via spontaneous vaginal delivery.

Conclusions: According to the COGEN position statement in 2017, mosaic blastocysts involving two or more chromosomes with mosaic levels exceeding 40% are typically ranked lowest for transfer. However, our case suggests that the implantation potential of mosaic embryos may be comparable to, if not greater than, that of their cohort euploid embryos when transferred within the same uterine environment. This observation raises the possibility that mosaic embryos possess a greater self-correction capacity than previously assumed, although further research is needed to substantiate this hypothesis.

Background: Infertility is a pervasive global health concern affecting millions of couples worldwide. Approximately 7% of the male population is infertile. Teratozoospermia, defined by > 96% abnormal sperm morphology, is a major cause of infertility often linked to genetic defects. In our previous study, we identified three AGTPBP1 mutations (p.Glu423Asp, p.Pro631Leu, and p.Arg811His) in teratozoospermia cases. AGTPBP1 is a key enzyme involved in regulating tubulin polyglutamylation and generating Δ-2 tubulin, a major structural component of the sperm tail and an essential structure for sperm head differentiation. However, functional proof of the impact of AGTPBP1 Arg811His on sperm head and tail impairment remained unestablished.

Methods: Knock-in mice carrying the equivalent mutation, Arg791His (R791H) corresponding to the human mutation (R811H), in the Agtpbp1 gene were generated and analyzed for sperm morphological abnormalities.

Results: Sperm morphological evaluation revealed a significant increase in the proportion of morphologically abnormal sperm in the Agtpbp1^R791H/R791H mice. Detailed morphological analysis revealed a significantly higher incidence of sperm head abnormalities and abnormal attachment of the head to the midpiece in the Agtpbp1^R791H/R791H mice relative to wild-type controls. Further, sperm with head defects from Agtpbp1^R791H/R791H mice exhibited abnormal accumulation of polyglutamylated tubulin within the sperm head. The mutant mice showed exactly the same morphological defects as seen in human patients and those displayed by mice lacking the complete carboxypeptidase A domain of AGTPBP1 but at a relatively lesser frequency.

Conclusions: We conclude that the R791H mutation in the Agtpbp1 gene impairs sperm head and tail differentiation, resulting in sperm morphological defects.

Pregnancy loss is the most common obstetric complication occurring in almost 15% of pregnancies. Of the examined products of conception (POC), approximately 60% of pregnancy losses result from chromosomal abnormalities and copy number variations (CNVs) in embryos, but genetic etiologies of euploid pregnancy loss remain largely unexplained. Previous studies suggest that genetic factors make a significant contribution to embryonic mortality. We aimed to review the results of current genomic studies of gene variants associated with miscarriage, including exome sequencing to look for pathogenic variants in the whole exome, as well as high-coverage whole-genome sequencing in families with miscarriages. We compared the lists of genes causative of or predisposing to miscarriage in parents and POCs. Additionally, we summarize novel genetic variants, which may be responsible for embryonic aneuploidy according to WES/WGS studies. Identification of genes that contribute to pregnancy loss is of importance in understanding the biological pathways that can cause pregnancy loss and an informative approach for discovering the key genes for human development. Knowledge of specific genes that contribute to pregnancy loss could also be valued in designing a diagnostic sequencing panel for patients with recurrent pregnancy loss.

Purpose: To evaluate whether the inflammatory proteomics of uterine fluid is feasible in defining the endometrial receptivity phase.

Methods: Inflammatory proteomics of uterine fluid was measured using the OLINK Target-96 Inflammation panel. Endometrial receptivity testing (ERT) combined with endometrial dating was used to define the phase of endometrial receptivity. A predictive model based on proteomics of uterine fluid was established to predict the endometrial receptivity phase.

Results: The inflammatory factors in uterine fluid were differentially expressed between the window of implantation (WOI) and displaced WOI groups; the displaced WOI group was characterized by increased expression of a variety of inflammatory factors. The predictive model established based on the top five differential proteins could classify the endometrial receptive phase. Transcriptomic data from endometrial tissues showed that the differential gene sets between different receptive phases were mostly enriched in immune-related processes, and the expression of immune-related genes in the WOI group was significantly lower than that in the displaced WOI group.

Conclusions: Detecting inflammatory proteins from the uterine fluid using the OLINK inflammation panel is feasible and holds promise as a novel non-invasive method to define endometrial receptivity phases.

Purpose: Oocyte quality declines with age and metabolic stress, largely due to mitochondrial dysfunction and NAD⁺ depletion. Nicotinamide mononucleotide (NMN), a precursor of NAD⁺, has emerged as a potential intervention to restore cellular energy metabolism. This study systematically reviews preclinical evidence on NMN supplementation and integrates transcriptomic analysis of human oocytes to assess its relevance in human fertility.

Methods: A systematic review was conducted following PRISMA guidelines across Medline, Embase, and Scopus (January 2015-October 2024). Seven high-quality original studies were included after screening and bias assessment. Data were synthesised through thematic analysis and pathway annotation. Additionally, single-oocyte RNA sequencing was performed on 46 human oocytes at germinal vesicle, metaphase I, and metaphase II stages to profile NAD⁺-related gene expression.

Results: Across animal models, NMN supplementation has been shown to improve mitochondrial regulation, reduce oxidative stress, and modulate apoptotic and inflammatory pathways in response to metabolic, environmental, and ageing stress. Transcriptomic analysis identified 900 differentially expressed genes between germinal vesicle and metaphase II oocytes, with significant changes in mitochondrial and oxidative stress-related genes (i.e. SIRT3, DNM1L, SOD1), aligned with NMN's known mechanisms of action.

Conclusions: NMN supplementation shows improvements for oocyte function across diverse preclinical models. Human transcriptomic data further highlight mitochondrial and oxidative pathways as key regulatory points during oocyte maturation. Standardised protocols and clinical trials are needed to evaluate NMN's translational potential in the context of human reproduction.

Purpose: To determine the prevalence of embryonic chromosomal abnormalities in patients with recurrent miscarriage (RM) and to assess whether there is a difference between primary and secondary RM.

Methods: Retrospective analysis of products of conception (POC) from patients with RM undergoing dilation and curettage. The prevalence of chromosomal aberrations was assessed in 351 POC specimens obtained from 327 patients with a history of three or more pregnancy losses, using quantitative fluorescence polymerase chain reaction (QF-PCR) and chromosomal microarray analysis (CMA). Patients were classified based on their obstetric history: those whose pregnancies all resulted in miscarriage (up to 22 weeks' gestation) without a prior live birth were categorized as having primary RM, whereas all others were classified as secondary RM.

Results: The overall incidence of embryonic chromosomal abnormalities was 47.6%, occurring in 56.7% of primary RM and 44.1% of secondary RM. A significant positive correlation was found between primary RM and embryonic chromosomal abnormalities (p = 0.008), despite the lower mean maternal age. In the secondary RM subgroup, each additional previous pregnancy which developed beyond 22 weeks significantly reduced the likelihood of embryonic chromosomal abnormalities (p < 0.001).

Conclusion: Primary RM patients showed a higher prevalence of embryonic chromosomal abnormalities, despite having a lower maternal age. A history of pregnancies progressing beyond 22 weeks was associated with a reduced likelihood of embryonic chromosomal abnormalities.

Purpose: To investigate how mitochondria and telomeres evolve during early follicle growth in human preantral follicles, and how these changes relate to reproductive age.

Methods: This prospective study included ovarian cortex and peripheral blood samples from 21 women, categorized into young (20-26, n = 7), mid (27-36, n = 6) and advanced (37-46, n = 8) reproductive age groups. Ovarian biopsies were processed for (i) follicle isolation for mitochondrial marker assessment (MitoTracker Deep Red and MitoSOX live staining) and telomerase subunit expression (hTERT, hTERC) by droplet digital PCR; and (ii) histological evaluation of the ovarian follicle pool, mitochondrial mass (TOMM20) and telomere length in different ovarian compartments (oocytes, granulosa cells and stroma) by fluorescence in situ hybridization (FISH). Leukocyte telomere length was measured by flow-FISH.

Results: Mitochondrial mass (TOMM20) in the follicle pool was stable across age groups, but increased significantly during early follicle growth in younger patients (p < 0.01). Active mitochondria did not decline with age, but reactive oxygen species (ROS) generation showed complex age-related patterns, with younger subjects exhibiting lower ROS levels during follicle growth (p < 0.01) than other age groups. Telomere length was stable in granulosa cells and oocytes within primordial follicles, but increased during growth in younger age groups. Telomerase subunit expression was detected in preantral follicles without any significant age or size differences.

Conclusions: These results point to greater mitochondrial mass, mitochondrial ability to limit ROS generation, and telomere dynamics changing with increasing age in early growing follicles, potentially guiding the development of strategies to enhance fertility outcomes during the early stages of folliculogenesis.

Purpose: Sperm mature as they transit through the epididymis, during which they gain progressive motility and the capability to fertilize oocytes. Autophagy plays a significant role in the regulation of testicular spermiogenesis. Autophagy-related gene 5 (Atg5) is recognized as a crucial regulator of autophagy progression. However, the role of Atg5 in regulating epididymal sperm maturation has yet to be elucidated.

Methods: To investigate the function of Atg5 in regulating epididymal sperm maturation, Atg5 conditional knockout mice were generated using Cre/LoxP technology, and sperm quality and fertility were assessed. Comprehensive quantitative analyses and bioinformatics evaluations of the proteome in segments 4-5 of the caput epididymis and sperm from the cauda epididymis were conducted.

Results: Atg5 deletion reduced autophagy in the caput epididymis but did not significantly affect sperm motility. Quantitative proteomics via data-independent acquisition (DIA) and subsequent bioinformatics analysis revealed significant alterations in the expression of several sperm proteins. Among these, the upregulated proteins were strongly associated with Atg5-independent surrogate autophagy, while the downregulated proteins were linked to sperm maturation. Additionally, qRT-PCR assays demonstrated that seven genes closely related to autophagy and sperm quality were differentially expressed in the 4-5 segments of the caput epididymis.

Conclusions: Atg5 affects protein expression and abundance in both the caput epididymis (segments 4-5) and cauda epididymal sperm, without statistically significant effects on sperm motility or male fertility. However, the potential impact of autophagy inhibition on sperm maturation may arise under challenging survival conditions by influencing the expression of sperm proteins.

Purpose: The aim of this study was to determine the predictive value of the morphokinetic parameter S2 (the duration between cleavage from the 3-cell to 4-cell stage in the absence of direct cleavage) for early embryo developmental potential, establish its optimal cutoff value, and explore associated metabolic pathways.

Methods: This prospective study analyzed 662 embryos from 65 patients (September 2023-October 2024) which were cultured in time-lapse incubators. S2's predictive value for blastocyst formation/quality was assessed, with a cutoff value calculated through receiver operating characteristic (ROC) analysis. Subsequently, metabolomic profiling of spent culture media (SCM) from 20 patients was stratified by S2 cutoff using liquid chromatography-tandem mass spectrometry (LC-MS).

Results: Among 662 embryos cultured in time-lapse incubators, 474 were analyzed to evaluate the association between S2 and developmental potential. Significant differences in S2 values were observed between the blastocyst formation vs. non-formation groups and high- vs. low-quality blastocyst groups (both median 0.5 vs. 0.8, P < 0.05). Logistic regression analysis showed that S2 predicted available blastocyst formation with an area under the curve (AUC) of 0.622 (95%CI = 0.559-0.685, P < 0.001) and blastocyst quality with an AUC of 0.645 (95% CI = 0.569-0.722), with an optimal cutoff of 0.7 h. Based on this cutoff, the day 3 (D3) SCM from 20 patients was divided into two groups (S2 < 0.7 and S2 ≥ 0.7) for metabolomic analysis. The results revealed 98 differentially expressed metabolites (59 upregulated and 39 downregulated), enriched in protein digestion/ absorption, aminoacyl-tRNA biosynthesis, fatty acid metabolism, central carbon metabolism in cancer, and glutamatergic synapse.

Conclusions: The S2 parameter (optimal cutoff = 0.70 h) shows moderate predictive capacity for embryo developmental potential (AUC = 0.64), with its regulation by specific metabolic pathways, supporting its inclusion in future multifactorial embryo evaluation models.

Purpose: To identify treatment-related factors influencing low oocyte maturation rates in standard ovarian stimulation (OS) cycles and patients' candidates for clinical studies on rescue-IVM.

Methods: Retrospective study including retrievals with ≥ 1 cumulus-oocyte-complex (COC; years: 2008-2022). The weighted-mean immaturityrate (19%) was defined in the whole dataset (N = 16,155). Variables associated with immaturity rates and warning limit (defined as weighted average + 2SD) were appraised among first retrievals with ≥ 5 COCs (N = 7962). Of the patients undergoing a first oocyte pick-up, 667 completed three retrieval cycles, enabling evaluation of the true prevalence of patients exceeding the immaturity rate warning threshold over multiple cycles.

Results: Factors influencing immaturity rate included OS duration, trigger type (GnRH-agonist versus urinary-hCG), ovulation trigger to oocytes' denudation interval and ratio COC to follicle > 14 mm at ovulation trigger. In first retrievals with ≥ 5 COCs, the immaturity rate warning limit was 51%, occurring in 3.6% of initial retrievals, 3.8% of second retrievals, and 2.1% of third retrievals. In three consecutive retrievals, the conservative prevalence of patients exceeding this threshold once, twice, and three times was 4.4%, 0.3%, and 0.03%, respectively. Assuming all patients would have conducted three retrievals, these rates were estimated as 7.8%, 1.5%, and 0.3%. In the 667 patients who conducted three retrievals, observed rates were 7.6%, 0.9%, and 0.4%, confirming the reliability of the estimates.

Conclusions: Ovarian stimulation and laboratory factors impact oocyte maturation rate. An oocyte immaturity rate exceeding 51%, in patients retrieving ≥ 5 oocytes, may represent a strong inclusion criterion for future clinical studies on rescue-IVM.