TUBB8 mutations as a cause of oocyte maturation abnormalities: presentation of oocyte and embryo profiles and novel mutations.

Research Question: What are the embryonic profiles and oocyte maturation dynamics in patients with tubulin beta eight class VIII (TUBB8) mutations leading to oocyte maturation abnormalities (OMAS), and are pregnancies possible in this population?

Design: A prospective cohort study was undertaken in a private fertility clinic between January 2019 and December 2022. Whole-exome genomic studies (WES) were performed to detect mutation types. In-vitro maturation (IVM) was compared in 18 subjects: nine with TUBB8 mutations, and nine without TUBB8 mutations to act as the control group.

Human ovarian aging is characterized by oxidative damage and mitochondrial dysfunction.

Study Question: Are human ovarian aging and the age-related female fertility decline caused by oxidative stress and mitochondrial dysfunction in oocytes?

Summary Answer: We found oxidative damage in oocytes of advanced maternal age, even at the primordial follicle stage, and confirmed mitochondrial dysfunction in such oocytes, which likely resulted in the use of alternative energy sources.

What Is Known Already: Signs of reactive oxygen species-induced damage and mitochondrial dysfunction have been observed in maturing follicles, and even in early stages of embryogenesis. However, although recent evidence indicates that also primordial follicles have metabolically active mitochondria, it is still often assumed that these follicles avoid oxidative phosphorylation to prevent oxidative damage in dictyate arrested oocytes.

Epidemiology of spontaneous pregnancy loss in Kazakhstan: A national population-based cohort analysis during 2014-2019 using the national electronic healthcare system.

Introduction: Spontaneous pregnancy loss (SPL) is a common health problem that affects 1:10 of childbearing women, and is linked with physical and psychological complications. As the number of nationwide studies on the incidence of SPL is few, especially from middle-income countries, in this study we investigated the epidemiology, complications and outcomes of SPL before 22 weeks of gestation by analyzing large-scale healthcare data from the Unified Nationwide Electronic Healthcare System (UNEHS) in Kazakhstan.

Material And Methods: A population-based study among women who experienced SPL in any healthcare setting of the Republic of Kazakhstan during the period of 2014-2019.

The association between the number of oocytes retrieved and cumulative live birth rate in different female age strata.

To evaluate the association between the number of oocytes retrieved and cumulative live birth rate (CLBR) in different female age strata. 17,931 women undergoing their first IVF/ICSI-ET cycle in the Sir Run Run Shaw Hospital of Zhejiang University were grouped by age (A: ≤ 35 years; B: ≥ 36 years) as well as the number of oocytes retrieved (a: ≤ 5; b:6-9; c:10-14; d: ≥ 15). Multivariate regression analysis was performed to assess the OR of CLBR for the variable 'age' and 'number of oocytes retrieved'.

Effects of dysregulated glucose metabolism on the occurrence and ART outcome of endometriosis.

Background: Endometriosis is associated with systemic metabolic indicators, including body mass index (BMI), glucose metabolism and lipid metabolism, while the association between metabolic indexes and the occurrence and assisted reproductive technology (ART) outcome of endometriosis is unclear. We aimed to evaluate the characteristics of systemic metabolic indexes of endometriosis patients with infertility and their effects on pregnancy outcome after ART treatment.

Methods: A retrospective cohort study involve 412 endometriosis patients and 1551 controls was conducted.

Maternal age and gonadotrophin elevation cooperatively decrease viable ovulated oocytes and increase ootoxicity, chromosome-, and spindle-misalignments: '2-Hit' and 'FSH-OoToxicity' mechanisms as new reproductive aging hypotheses.

While there is consensus that advanced maternal age (AMA) reduces oocyte yield and quality, the notion that high FSH reduces oocyte quality and causes aneuploidy remains controversial, perhaps due to difficulties controlling the confounding variables of age and FSH levels. Here, contributions of age and gonadotrophin elevation were separately controlled using a mouse model of human female reproductive aging. Ovulated oocytes were collected from young and midlife mice after 0-, 2.

Mutations in CCNB3 affect its location thus causing a multiplicity of phenotypes in human oocytes maturation by aberrant CDK1 activity and APC/C activity at different stages.

Background: Oocyte maturation arrest results in female infertility and the genetic etiology of this phenotype remains largely unknown. Previous studies have proven that cyclins play a significant role in the cell cycle both in meiosis and mitosis. Cyclin B3 (CCNB3) is one of the members of the cyclin family and its function in human oocyte maturation is poorly understood.

MicroRNA-338-3p helps regulate ovarian function by affecting granulosa cell function and early follicular development.

Background: Follicular development in mammalian ovaries is a complex and dynamic process, and the interactions and regulatory-feedback loop between the follicular microenvironment, granulosa cells (GCs), and oocytes can affect follicular development and normal ovary functions. Abnormalities in any part of the process may cause abnormal follicular development, resulting in infertility. Hence, exploring the pathogenesis of abnormal follicular development is extremely important for diagnosing and treating infertile women.

Free your patients and yourself from day 2-3: start ovarian stimulation any time in freeze-all cycles.

Ovarian stimulation for assisted reproductive technology is traditionally started in the early follicular phase. The essential rationale is to allow timely follicle growth and oocyte retrieval to ensure synchronization of the in-vitro cultured embryos with the receptive period of the endometrium in a fresh transfer cycle. In addition, conventional thought suggested that follicle recruitment happened only once, around menstruation.

Integrating imaging-based classification and transcriptomics for quality assessment of human oocytes according to their reproductive efficiency.

Purpose: Utilising non-invasive imaging parameters to assess human oocyte fertilisation, development and implantation; and their influence on transcriptomic profiles.

Methods: A ranking tool was designed using imaging data from 957 metaphase II stage oocytes retrieved from 102 patients undergoing ART. Hoffman modulation contrast microscopy was conducted with an Olympus IX53 microscope.

A Proteomic Analysis of Human Follicular Fluid: Proteomic Profile Associated with Embryo Quality.

Embryo selection is a key point of in vitro fertilization (IVF). The most commonly used method for embryo selection is morphological assessment. However, it is sometimes inaccurate.

Ambient black carbon particles in human ovarian tissue and follicular fluid.

Evidence indicates a link between exposure to ambient air pollution and decreased female fertility. The ability of air pollution particles to reach human ovarian tissue and follicles containing the oocytes in various maturation stages has not been studied before. Particulate translocation might be an essential step in explaining reproductive toxicity and assessing associated risks.

The Aging Ovary and the Tales Learned Since Fetal Development.

Background: While the term "aging" implies a process typically associated with later life, the consequences of ovarian aging are evident by the time a woman reaches her forties, and sometimes earlier. This is due to a gradual decline in the quantity and quality of oocytes which occurs over a woman's reproductive lifespan. Indeed, the reproductive potential of the ovary is established even before birth, as the proper formation and assembly of the ovarian germ cell population during fetal life determines the lifetime endowment of oocytes and follicles.

Evaluation of TUBB8 gene alterations in infertile women with oocyte maturation and cleavage arrest referred to Royan Institute.

Research Question: Are TUBB8 gene variations present in Iranian infertile women with oocyte maturation arrest or embryo cleavage arrest?

Design: TUBB8 gene variations were investigated by polymerase chain reaction sequencing on blood samples from 16 women with oocyte maturation arrest and 12 women with cleavage arrest, collectively referred to as the experimental cohort, as well as 56 fertile women as the control group. The Exome Sequencing Project and dbSNP databases and the Genome Aggregation Database were used to search the frequency of corresponding variants. PolyPhen and SIFT were used to conduct in-silico analysis of gene variations and Align-GVGD was used to predict the effect of missense variants on proteins.

Control of mitochondrial integrity influences oocyte quality during reproductive aging.

Reduced quality in oocytes from women of advanced maternal age (AMA) is associated with dysfunctional mitochondria. The objective of this study was to investigate the mechanisms controlling mitochondrial quality during maternal aging in mouse and human oocytes. We first evaluated the expression of proteins involved in the mitochondrial unfolded protein response (UPRmt) and mitophagy in in vivo matured metaphase II (MII) oocytes collected from young and aged mice.

Measurement of ovarian reserve in infertile versus fertile women: A case control study in Edo State, Nigeria.

The reproductive potential in a woman is age related. Nevertheless, the female reproductive system undergoes ovarian follicular development, resulting in ovulation of matured ovum for fertilization. Consequently, female reproductive aging parallels the depletion of the store of follicles until menopause is attained.

The dynamic expression of SOX17 in germ cells from human female foetus and adult ovaries after specification.

Background: SOX17 has been identified as a critical factor in specification of human primordial germ cells, but whether SOX17 regulates development of germ cells after sex differentiation is poorly understood.

Methods: We collected specimens of gonadal ridge from an embryo (n=1), and ovaries of foetuses (n=23) and adults (n=3). Germ cells were labelled with SOX17, VASA (classic germ cells marker), phosphohistone H3 (PHH3, mitosis marker) and synaptonemal complex protein 3 (SCP3, meiosis marker).

Fertility preservation after gonadotoxic treatments for cancer and autoimmune diseases.

Background: The indications for fertility preservation (FP) have expanded. A few patients who underwent gonadotoxic treatment did not have the opportunity to receive FP, leading to concerns that these patients may develop premature ovarian insufficiency. However, the usefulness of FP in women with reduced ovarian reserve has also been questioned.

Systematic review of mRNA expression in human oocytes: understanding the molecular mechanisms underlying oocyte competence.

The biggest cell in the human body, the oocyte, encloses almost the complete machinery to start life. Despite all the research performed to date, defining oocyte quality is still a major goal of reproductive science. It is the consensus that mature oocytes are transcriptionally silent although, during their growth, the cell goes through stages of active transcription and translation, which will endow the oocyte with the competence to undergo nuclear maturation, and the oocyte and embryo to initiate timely translation before the embryonic genome is fully activated (cytoplasmic maturation).

Unreprogrammed H3K9me3 prevents minor zygotic genome activation and lineage commitment in SCNT embryos.

Somatic cell nuclear transfer (SCNT) can be used to reprogram differentiated somatic cells to a totipotent state but has poor efficiency in supporting full-term development. H3K9me3 is considered to be an epigenetic barrier to zygotic genomic activation in 2-cell SCNT embryos. However, the mechanism underlying the failure of H3K9me3 reprogramming during SCNT embryo development remains elusive.

Effectiveness of oestrogen pretreatment in patients with expected poor ovarian response (POSEIDON groups 3 and 4) undergoing GnRH antagonist protocol: study protocol for a randomised controlled trial.

Introduction: Women characterised by diminished ovarian reserve are considered to have poor ovarian response (POR) according to Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number (POSEIDON) criteria. Patients in this population often have a poor prognosis for treatment with assisted reproductive technology. In previous studies, oestrogen pretreatment before ovarian stimulation has been shown to have a beneficial effect.