In vitro growth of secondary follicles from cryopreserved-thawed ovarian cortex

STUDY QUESTION

Can secondary follicles be obtained from cultured cryopreserved-thawed human ovarian cortical tissue?

SUMMARY ANSWER

We obtained high-quality secondary follicles from cultured cryopreserved-thawed human ovarian cortical tissue from cis female donors (cOVA), but not from trans masculine donors (tOVA) in the same culture conditions.

WHAT IS KNOWN ALREADY

The in vitro growth of oocytes present in unilaminar follicles into metaphase II stage (MII) oocytes has been previously achieved starting from freshly obtained ovarian cortical tissue from adult cis female donors. This involved a multi-step culture protocol and the first step included the transition from unilaminar follicles to multilayered secondary follicles. Given that the ovarian cortex (from both cis female and trans masculine donors) used for fertility preservation is cryopreserved, it is crucial to investigate the potential of unilaminar follicles from cryopreserved-thawed ovarian cortex to grow in culture.

STUDY DESIGN, SIZE, DURATION

Cryopreserved-thawed ovarian cortical tissue from adult trans masculine donors (n = 3) and adult cis female donors (n = 3) was used for in vitro culture following the first culture step described in two published culture protocols (7-8 days and 21 days) and compared to freshly isolated ovarian cortex from trans masculine donors (n = 3) and to ovarian cortex prior to culture.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian cortical tissue was obtained from adult trans masculine donors undergoing gender-affirming surgery while using testosterone, and from adult cis female donors undergoing oophorectomy for fertility preservation purposes before chemotherapy. The ovarian cortex was fixed either prior (day 0) or after the culture period. Follicular survival, growth, and morphology were assessed through histology and immunofluorescence.

MAIN RESULTS AND THE ROLE OF CHANCE

We quantified the different stages of follicular development (primordial, primary, secondary, and atretic) after culture and observed an increase in the percentage of secondary follicles as well as an increase in COLIV deposition in the stromal compartment regardless of the culture media used. The quality of the secondary follicles obtained from cOVA was comparable to those prior to culture. However, in the same culture conditions, the secondary follicles from tOVA (fresh and cryo) showed low-quality secondary follicles, containing oocytes with small diameter, granulosa cells that expressed abnormal levels of KRT19 and steroidogenic-marker STAR and lacked ACTA2+ theca cells, when compared to tOVA secondary follicles prior to culture.

LIMITATIONS, REASONS FOR CAUTION

The number of different donors used was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Our study revealed that cryopreserved-thawed cOVA can be used to generate high-quality secondary follicles after culture and those can now be further tested to evaluate their potential to generate functional MII oocytes that could be used in the clinic. However, using the same culture protocol on tOVA (fresh and cryo) did not yield high-quality secondary follicles, suggesting that either the testosterone treatment affects follicular quality or adapted culture protocols are necessary to obtain high-quality secondary follicles from tOVA. Importantly, caution must be taken when using tOVA to optimize folliculogenesis in vitro.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the European Research Council Consolidator Grant OVOGROWTH (ERC-CoG-2016-725722 to J.S.D.V. and S.M.C.D.S.L.), the Novo Nordisk Foundation (reNEW NNF21CC0073729 to H.C., F.W., J.S.D.V., S.M.C.D.S.L.), and China Scholarship Council (CSC 202008320362 and CSC 202008450034 to H.C. and F.W.), respectively. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

A spotlight on factors influencing the in vitro folliculogenesis of isolated preantral follicles

Female fertility preservation via complete in vitro folliculogenesis is still chimerical. Due to many factors affecting the efficiency of isolation and culture of preantral follicles, the improvement of techniques geared to fertility preservation in higher mammals seems to be at an impasse. We need an objective view of the current stand to understand how to progress further. As such, a survey was conducted to analyze the relative distribution of studies performed in ten mammalian species on preantral follicle culture available on PubMed. Using the bovine as a reference model, we explore some factors influencing data variation that contribute to the difficulty in reproducing studies. While years of research have enabled the recapitulation of folliculogenesis from as modest as the early antral follicle stage ex vivo, in vitro preantral folliculogenesis remains elusive. Herein, we revisit the classical evidence that laid the foundations for understanding preantral folliculogenesis and review the length, breadth, and depth of information that the era of big data has currently levied. Moving forward, we recognize the urgency of synthesizing the multi-disciplinary approaches to mimic folliculogenesis in vitro to achieve a translational landscape of infertility at individual and large-scale conservation levels.

Early menstrual cycle impacts of oestrogen and progesterone on the timing of the fertile window

STUDY QUESTION

What is the effect of oestrogen and progesterone at the beginning of the menstrual cycle in delaying entry into the fertile window?

SUMMARY ANSWER

Both oestrogen and progesterone contribute to a delay in the onset of the fertile window.

WHAT IS KNOWN ALREADY

Oestrogen enhances cervical mucus secretion while progesterone inhibits it.

STUDY DESIGN, SIZE, DURATION

Observational study. Daily observation of 220 menstrual cycles contributed by 88 women with no known menstrual cycle disorder.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women recorded cervical mucus daily and collected first-morning urine samples for analysis of oestrone-3-glucuronide, pregnanediol-3-alpha-glucuronide (PDG), FHS, and LH. They underwent serial ovarian ultrasound examinations. The main outcome measure was the timing within the cycle of the onset of the fertile window, as identified by the appearance of mucus felt or seen at the vulva.

MAIN RESULTS AND THE ROLE OF CHANCE

Low oestrogen secretion and persistent progesterone secretion during the first week of the menstrual cycle both negatively affect mucus secretion. Doubling oestrogen approximately doubled the odds of entering the fertile window (OR: 1.82 95% CI=1.23; 2.69). Increasing PDG from below 1.5 to 4 µg/mg creatinine was associated with a 2-fold decrease in the odds of entering the fertile window (OR: 0.51 95% CI=0.31; 0.82). Prolonged progesterone secretion during the first week of the menstrual cycle was also statistically significantly associated with higher LH secretion. Finally, the later onset of the fertile window was associated with statistically significant persistently elevated LH secretion during the luteal phase of the previous menstrual cycle.

LIMITATIONS, REASONS FOR CAUTION

This post hoc study was conducted to assess the potential impact of residual progesterone secretion at the beginning of the menstrual cycle. It was conducted on an existing data set because of the scarcity of data available to answer the question. Analysis with other datasets with similar hormone results would be useful to confirm these findings.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides evidence for residual progesterone secretion in the early latency phase of some menstrual cycles, which may delay the onset of the fertile window. This progesterone secretion may be supported by subtly increased LH secretion during the few days before and after the onset of menses, which may relate to follicular waves in the luteal phase. Persistent progesterone secretion should be considered in predicting the onset of the fertile window and in assessing ovulatory dysfunction.

STUDY FUNDING/COMPETING INTEREST(S)

The authors declare no conflicts of interest. No funding was provided for this secondary data analysis.

TRIAL REGISTRATION NUMBER

N/A.

Inducers and Inhibitors of Pyroptotic Death of Granulosa Cells in Models of Premature Ovarian Insufficiency and Polycystic Ovary Syndrome

Granulosa cells (GCs), the largest cell population and primary source of steroid hormones in the ovary, are the important somatic ovarian components. They have critical roles in folliculogenesis by supporting oocyte, facilitating its growth, and providing a microenvironment suitable for follicular development and oocyte maturation, thus having essential functions in maintaining female fertility and in reproductive health in general. Pyroptotic death of GCs and associated inflammation have been implicated in the pathogenesis of several reproductive disorders in females including Premature Ovarian Insufficiency (POI) and Polycystic Ovary Syndrome (PCOS). Here, I reviewed factors, either intrinsic or extrinsic, that induce or inhibit pyroptosis in GCs in various models of these disorders, both in vitro and in vivo, and also covered associated molecular mechanisms. Most of these studied factors influence NLRP3 inflammasome- and GSDMD (Gasdermin D)-mediated pyroptosis in GCs, compared to other inflammasomes and gasdermins (GSDMs). I conclude that a more complete mechanistic understanding of these factors in terms of GC pyroptosis is required to be able to develop novel strategies targeting inflammatory cell death in the ovary.

The dark side of random-start ovarian stimulation: ovarian hyperstimulation syndrome due to inadvertent pregnancy

RESEARCH QUESTION

Can inadvertent pregnancies go unnoticed when initiating random-start ovarian stimulation (RSOS) despite monitoring?

DESIGN

Case series at a university-based tertiary care fertility clinic.

RESULTS

Between June 2022 and December 2023, two cases of undetected early pregnancy at the onset of RSOS were identified, both leading to severe ovarian hyperstimulation syndrome (OHSS) with hospitalization.

CONCLUSION

RSOS protocols add flexibility in fertility clinics when there is no intention of a fresh embryo transfer, but may be associated with insidious risk of OHSS. The authors advocate for comprehensive consultation and serial monitoring of human chorionic gonadotrophin during ovarian stimulation, while cautioning against over-reliance on baseline hormone concentrations when initiating RSOS. If the benefits of RSOS seem limited, healthcare providers should consider delaying ovarian stimulation to avert health, but also medicolegal and financial, complications.

COVID-19 and Female Fertility: An Observational Prospective Multicenter Cohort Study: Upholding Reproductive Rights in Emergency Circumstances

OBJECTIVES

Currently available research data points to COVID-19-related multi-organ system damage. This study aims to evaluate the impact of SARS-CoV-2 on the reproductive health, that is, plasma levels of FSH, LH, estradiol, AMH, and antral follicular count, of women undergoing level II ART techniques.

METHODS

This is a multicenter, prospective, and observational study by the reproductive medicine centers of Palermo's Ospedali Riuniti Villa Sofia-Cervello Hospital and Vanvitelli University. From September 2022 to March 2024, 203 patients aged 24-43 were enrolled, all with diagnosed infertility and a history of SARS-CoV-2 infection. Symptomatic women, patients testing positive for HIV or other liver viruses, and patients with a history of ovarian cancer or who had taken gonadotoxic drugs were excluded. Plasma measurements of FSH, LH, estradiol, AMH, and antral follicular count were performed before and after infection.

RESULTS

The analysis accounting for the concentration of anti-Müllerian hormone (AMH) before and after COVID-19 infection shows an average concentration decrease from 1.33 ng/mL before SARS-CoV-2 infection to 0.97 ng/mL after infection. Average decrease after infection was -27.4%; average reduction of 1 follicle (95% CI: from -0.74 to -1.33) was reported following SARS-CoV-2 infection. Levels of E2 before and after SARS-CoV-2 infection did not vary significantly. Average FSH and LH levels before and after SARS-CoV-2 infection pointed to an increase.

CONCLUSIONS

SARS-CoV-2 infection damages female reproductive health, causing significant reductions in AMH (-27.4%) and AFC (-1 antral follicle) values and an increase in FSH (+13.6%) and LH (+13.4%) values. No effect on E2 levels was reported. The pandemic has also affected the ability of infertile patients to access ART procedures, and that calls for a novel, updated blueprint designed to enhance our preparedness in the event that similar circumstances should occur again.

Early versus late follicular phase ovarian stimulation: a randomized controlled trial

RESEARCH QUESTION

Is late follicular phase stimulation as efficient as early follicular phase stimulation in a gonadotrophin-releasing hormone (GnRH) antagonist protocol in oocyte donors in terms of the number of oocytes.

DESIGN

In this open label, phase 3, non-inferiority, randomized controlled trial using a two-arm design with a 1:1 allocation ratio, 84 oocyte donors were allocated to the early follicular start group (control group, n = 41) or the late follicular start group (study group, n = 43). In the control group, women followed a fixed GnRH antagonist protocol with recombinant FSH (r-FSH) 225 IU. In the study group, r-FSH 225 IU was initiated in the late follicular phase. The primary outcome was the number of oocytes. The secondary outcomes were the number of mature oocytes, consumption of gonadotrophins and GnRH antagonist, and cost of medication.

RESULTS

The number of oocytes did not differ between the control group and the study group (intent-to-treat analysis 15.5 ± 11.0 versus 14.0 ± 10.7, P = 0.52; per-protocol analysis 18.2 ± 9.7 versus 18.8 ± 7.8, P = 0.62). In addition, the number of mature oocytes did not differ between the groups (14.1 ± 8.1 versus 12.7 ± 8.5, P = 0.48). The duration of stimulation was shorter in the control group (10.0 ± 1.4 versus 10.9 ± 1.5 days, P = 0.01). The total amount of r-FSH used was lower in the control group (2240.7 ± 313.9 IU versus 2453.9 ± 330.1 IU, P = 0.008). A GnRH antagonist was used for approximately 6 days in the control group, while a GnRH antagonist was only prescribed for one woman in the study group (6.0 ± 1.4 days versus 0.13±0.7 days, P < 0.001). There was a significant difference in the cost of medication per cycle between the groups (1147.9 ± 182.8€ in control group versus 979.9 ± 129.0€ in study group, P < 0.001).

CONCLUSIONS

Late follicular phase stimulation is as efficient as early follicular phase stimulation in terms of the number of oocytes.

KIT in oocytes: a key factor for oocyte survival and reproductive lifespan

BACKGROUND

The KITL-KIT interaction is known as an important initiator in oocyte activation through the downstream pathway of PI3K-AKT-FOXO3 signalling. Previous studies utilising germ cell-specific Kit mutant knockin and kinase domain knockout models with Vasa-Cre suggested the crucial role of KIT in oocyte activation at the primordial follicle stage.

METHODS

We utilised mice with complete postnatal deletion of KIT expression in oocytes via Gdf9-iCre and conducted analyses on ovarian follicle development, specific markers, hormone assays, and fertility outcomes.

FINDINGS

Our findings reveal contrasting phenotypes compared to previous mouse models with prenatal deletion of Kit. Specifically, postnatal deletion of Kit exhibit no defects in germ cell nest breakdown, follicle activation, and folliculogenesis during development. Remarkably, upon reaching full maturity, mice with postnatal deletion of Kit experience a complete loss of ovarian reserve, growing follicles, and ovarian function. Furthermore, mice display smaller ovarian size and weight, delayed folliculogenesis, and phenotypes indicative of primary ovarian insufficiency (POI), including elevated serum levels of FSH, reduced AMH, and absence of ovarian follicles, ultimately resulting in infertility. Additionally, the ovaries exhibit randomly distributed expression of granulosa and theca cell markers such as Inhibin α, ACVR2B, and LHR. Notably, there is the uncontrolled expression of p-SMAD3 and Ki67 throughout the ovarian sections, along with the widespread presence of luteinised stroma cells and cleaved Caspase-3-positive dying cells.

INTERPRETATION

These genetic studies underscore the indispensable role of KIT in oocytes for maintaining the survival of ovarian follicles and ensuring the reproductive lifespan.

FUNDING

This work was supported by National Institutes of Health grant R01HD096042 and startup funds from UNMC (S.Y.K.).

Follicular Atresia in Buffalo: Cocaine- and Amphetamine-Regulated Transcript (CART) and the Underlying Mechanisms

Atresia is a process in ovarian follicles that is regulated by hormone-induced apoptosis. During atresia, granulosa cell (GC) apoptosis is a key mechanism orchestrated through diverse signaling pathways. Cocaine- and amphetamine-regulated transcript (CART) signaling within ovarian GCs has been demonstrated to play a key role in the regulation of follicular atresia in cattle, pigs, and sheep. The present work aimed to investigate the potential local regulatory role of CART in GC apoptosis-induced follicular atresia in buffalo, focusing on the modulation of the AKT/GSK3β/β-catenin signaling pathways, which are the intracellular signaling pathways involved in cell viability. Our findings revealed increased expression of CARTPT and BAX and decreased levels of AKT, β-catenin, and CYP19A1 genes in atretic follicles compared to healthy follicles. Subsequently, CART treatment in the presence of FSH inhibited the FSH-induced increase in GC viability by reducing estradiol production and increasing apoptosis. This change was accompanied by an increase in the gene expression levels of both CARTPT and BAX. At the protein level, treatment with CART in the presence of FSH negatively affected the activity of AKT, β-catenin, and LEF1, while the activity of GSK3β was enhanced. In conclusion, our study shows how CART negatively influences buffalo GC viability, underlying the modulation of the AKT/GSK3β/β-catenin pathway and promoting apoptosis-a key factor in follicular atresia.

Three-Dimensionally Printed Agarose Micromold Supports Scaffold-Free Mouse Ex Vivo Follicle Growth, Ovulation, and Luteinization

Ex vivo follicle growth is an essential tool, enabling interrogation of folliculogenesis, ovulation, and luteinization. Though significant advancements have been made, existing follicle culture strategies can be technically challenging and laborious. In this study, we advanced the field through development of a custom agarose micromold, which enables scaffold-free follicle culture. We established an accessible and economical manufacturing method using 3D printing and silicone molding that generates biocompatible hydrogel molds without the risk of cytotoxicity from leachates. Each mold supports simultaneous culture of multiple multilayer secondary follicles in a single focal plane, allowing for constant timelapse monitoring and automated analysis. Mouse follicles cultured using this novel system exhibit significantly improved growth and ovulation outcomes with comparable survival, oocyte maturation, and hormone production profiles as established three-dimensional encapsulated in vitro follicle growth (eIVFG) systems. Additionally, follicles recapitulated aspects of in vivo ovulation physiology with respect to their architecture and spatial polarization, which has not been observed in eIVFG systems. This system offers simplicity, scalability, integration with morphokinetic analyses of follicle growth and ovulation, and compatibility with existing microphysiological platforms. This culture strategy has implications for fundamental follicle biology, fertility preservation strategies, reproductive toxicology, and contraceptive drug discovery.

Serum INSL3 measured by LC-MS/MS in pubertal girls and in girls with precocious puberty during GnRH agonist treatment

Introduction

The peptide hormone Insulin-like Factor 3 (INSL3) is a biomarker of testicular Leydig cells in the male but is also expressed by the theca cells of the ovaries. With the advent of sensitive assays INSL3 can be quantified in female circulation, and we suggest that circulating INSL3 is a novel biomarker for pubertal development in girls. The aim of the study is to quantify INSL3 by LC-MS/MS in sera from normal girls during pubertal transition, and during gonadal suppression by GnRH agonist therapy in girls with central precocious puberty (CPP).

Method

The sensitivity of an established LC-MS/MS-based method for serum INSL3 was improved by switching to a state-of-the-art triple quadruple mass spectrometer (Altis Plus, Thermo).

Results

The limit of detection of the improved LC-MS/MS method for serum INSL3 was 0.01 ug/L (1.5 pM) and the inter-assay CV was < 12%. Serum INSL3 increased during the pubertal transition in healthy girls and changes correlated with the concomitant rise in other measured hormones. In some girls, but not all, INSL3, FSH, inhibin B and estradiol serum concentrations increased prior to first clinical signs of puberty. Serum INSL3 concentrations were increased at baseline in girls with CPP compared to prepubertal controls and decreased during treatment with GnRH agonist followed by a steep rise and normalization after cessation of treatment.

Conclusion

The improved method allowed for quantification of INSL3 in longitudinally collected serum samples during pubertal transition in healthy girls as well as in girls with CPP before, during and after treatment with GnRH agonist. Future studies are needed to clarify if INSL3 in combination with other biomarkers enhances the predictive value of differentiating between premature thelarche and CPP.

Weightlessness leads to an increase granulosa cells in the growing follicle

The participation of women in space programs of increasing flight duration requires research of their reproductive system from the perspective of subsequent childbearing and healthy aging. For the first time, we present hormonal and structural data on the dynamics of recovery after a 157-day space flight in a woman of reproductive age. There were no clinically significant changes in the reproductive system, but detailed analysis shows that weightlessness leads to an increase in the proportion of early antral follicles and granulosa cells in large antral follicles. Returning to Earth's gravity reduces the number and diameter of early antral follicles.

Nonlinear compartmental modeling to monitor ovarian follicle population dynamics on the whole lifespan

In this work, we introduce a compartmental model of ovarian follicle development all along lifespan, based on ordinary differential equations. The model predicts the changes in the follicle numbers in different maturation stages with aging. Ovarian follicles may either move forward to the next compartment (unidirectional migration) or degenerate and disappear (death). The migration from the first follicle compartment corresponds to the activation of quiescent follicles, which is responsible for the progressive exhaustion of the follicle reserve (ovarian aging) until cessation of reproductive activity. The model consists of a data-driven layer embedded into a more comprehensive, knowledge-driven layer encompassing the earliest events in follicle development. The data-driven layer is designed according to the most densely sampled experimental dataset available on follicle numbers in the mouse. Its salient feature is the nonlinear formulation of the activation rate, whose formulation includes a feedback term from growing follicles. The knowledge-based, coating layer accounts for cutting-edge studies on the initiation of follicle development around birth. Its salient feature is the co-existence of two follicle subpopulations of different embryonic origins. We then setup a complete estimation strategy, including the study of structural identifiability, the elaboration of a relevant optimization criterion combining different sources of data (the initial dataset on follicle numbers, together with data in conditions of perturbed activation, and data discriminating the subpopulations) with appropriate error models, and a model selection step. We finally illustrate the model potential for experimental design (suggestion of targeted new data acquisition) and in silico experiments.

Reproductive toxicity of PFOA, PFOS and their substitutes: A review based on epidemiological and toxicological evidence

Per- and polyfluoroalkyl substances (PFAS) have already drawn a lot of attention for their accumulation and reproductive toxicity in organisms. Perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS), two representative PFAS, are toxic to humans and animals. Due to their widespread use in environmental media with multiple toxicities, PFOA and PFOS have been banned in numerous countries, and many substitutes have been produced to meet market requirements. Unfortunately, most alternatives to PFOA and PFOS have proven to be cumulative and highly toxic. Of the reported multiple organ toxicities, reproductive toxicity deserves special attention. It has been confirmed through epidemiological studies that PFOS and PFOA are not only associated with reduced testosterone levels in humans, but also with an association with damage to the integrity of the blood testicular barrier. In addition, for women, PFOA and PFOS are correlated with abnormal sex hormone levels, and increase the risk of infertility and abnormal menstrual cycle. Nevertheless, there is controversial evidence on the epidemiological relationship that exists between PFOA and PFOS as well as sperm quality and reproductive hormones, while the evidence from animal studies is relatively consistent. Based on the published papers, the potential toxicity mechanisms for PFOA, PFOS and their substitutes were reviewed. For males, PFOA and PFOS may produce reproductive toxicity in the following five ways: (1) Apoptosis and autophagy in spermatogenic cells; (2) Apoptosis and differentiation disorders of Leydig cells; (3) Oxidative stress in sperm and disturbance of Ca2+ channels in sperm membrane; (4) Degradation of delicate intercellular junctions between Sertoli cells; (5) Activation of brain nuclei and shift of hypothalamic metabolome. For females, PFOA and PFOS may produce reproductive toxicity in the following five ways: (1) Damage to oocytes through oxidative stress; (2) Inhibition of corpus luteum function; (3) Inhibition of steroid hormone synthesis; (4) Damage to follicles by affecting gap junction intercellular communication (GJIC); (5) Inhibition of placental function. Besides, PFAS substitutes show similar reproductive toxicity with PFOA and PFOS, and are even more toxic to the placenta. Finally, based on the existing knowledge, future developments and direction of efforts in this field are suggested.

A Molecular Perspective and Role of NAD+ in Ovarian Aging

The decline in female fecundity is linked to advancing chronological age. The ovarian reserve diminishes in quantity and quality as women age, impacting reproductive efficiency and the aging process in the rest of the body. NAD+ is an essential coenzyme in cellular energy production, metabolism, cell signaling, and survival. It is involved in aging and is linked to various age-related conditions. Hallmarks associated with aging, diseases, and metabolic dysfunctions can significantly affect fertility by disturbing the delicate relationship between energy metabolism and female reproduction. Enzymes such as sirtuins, PARPs, and CD38 play essential roles in NAD+ biology, which actively consume NAD+ in their enzymatic activities. In recent years, NAD+ has gained much attention for its role in aging and age-related diseases like cancer, Alzheimer's, cardiovascular diseases, and neurodegenerative disorders, highlighting its involvement in various pathophysiological processes. However, its impact on female reproduction is not well understood. This review aims to bridge this knowledge gap by comprehensively exploring the complex interplay between NAD+ biology and female reproductive aging and providing valuable information that could help develop plans to improve women's reproductive health and prevent fertility issues.

GDF9His209GlnfsTer6/S428T and GDF9Q321X/S428T bi-allelic variants caused female subfertility with defective follicle enlargement

BACKGROUND

Antral follicles consist of an oocyte cumulus complex surrounding by somatic cells, including mural granulosa cells as the inner layer and theca cells as the outsider layer. The communications between oocytes and granulosa cells have been extensively explored in in vitro studies, however, the role of oocyte-derived factor GDF9 on in vivo antral follicle development remains elusive due to lack of an appropriate animal model. Clinically, the phenotype of GDF9 variants needs to be determined.

METHODS

Whole-exome sequencing (WES) was performed on two unrelated infertile women characterized by an early rise of estradiol level and defect in follicle enlargement. Besides, WES data on 1,039 women undergoing ART treatment were collected. A Gdf9Q308X/S415T mouse model was generated based on the variant found in one of the patients.

RESULTS

Two probands with bi-allelic GDF9 variants (GDF9His209GlnfsTer6/S428T, GDF9Q321X/S428T) and eight GDF9S428T heterozygotes with normal ovarian response were identified. In vitro experiments confirmed that these variants caused reduction of GDF9 secretion, and/or alleviation in BMP15 binding. Gdf9Q308X/S415T mouse model was constructed, which recapitulated the phenotypes in probands with abnormal estrogen secretion and defected follicle enlargement. Further experiments in mouse model showed an earlier expression of STAR in small antral follicles and decreased proliferative capacity in large antral follicles. In addition, RNA sequencing of granulosa cells revealed the transcriptomic profiles related to defective follicle enlargement in the Gdf9Q308X/S415T group. One of the downregulated genes, P4HA2 (a collagen related gene), was found to be stimulated by GDF9 protein, which partly explained the phenotype of defective follicle enlargement.

CONCLUSIONS

GDF9 bi-allelic variants contributed to the defect in antral follicle development. Oocyte itself participated in the regulation of follicle development through GDF9 paracrine effect, highlighting the essential role of oocyte-derived factors on ovarian response.

Spatiotemporal transcriptomic changes of human ovarian aging and the regulatory role of FOXP1

Limited understanding exists regarding how aging impacts the cellular and molecular aspects of the human ovary. This study combines single-cell RNA sequencing and spatial transcriptomics to systematically characterize human ovarian aging. Spatiotemporal molecular signatures of the eight types of ovarian cells during aging are observed. An analysis of age-associated changes in gene expression reveals that DNA damage response may be a key biological pathway in oocyte aging. Three granulosa cells subtypes and five theca and stromal cells subtypes, as well as their spatiotemporal transcriptomics changes during aging, are identified. FOXP1 emerges as a regulator of ovarian aging, declining with age and inhibiting CDKN1A transcription. Silencing FOXP1 results in premature ovarian insufficiency in mice. These findings offer a comprehensive understanding of spatiotemporal variability in human ovarian aging, aiding the prioritization of potential diagnostic biomarkers and therapeutic strategies.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Exploring the potential use of platelet rich plasma (PRP) from adult and umbilical cord blood in murine follicle culture

Ovarian follicle culture is a powerful tool to study follicular physiology and has potential applications in clinical and commercial settings. Despite remarkable progress, recreating folliculogenesis in vitro remains challenging for many mammalian species. This study investigates the impact of platelet-rich plasma (PRP) derived from adult blood (human platelet lysate, hPL) and umbilical cord blood (Umbilical cord plasma, UCP) on murine pre-antral follicle culture and oocyte maturation. Pre-antral follicles were cultured individually for 10 days with fetal bovine serum (FBS) serving as the control and two PRP sources (hPL and UCP) and their activated forms (Ac-hPL and Ac-UCP). The results suggest that neither hPL nor UCP, regardless of activation status, improved follicle culture outcomes compared to FBS. Interestingly, activation did not significantly impact the main functional outcomes such as maturation rates, survival, and growth. Oestradiol secretion and oocyte diameter, often considered hallmarks of follicle quality, did not show significant differences between matured and non-matured oocytes across the treatment groups. However, gene expression analysis revealed a significant upregulation of Gdf-9 and Bmp-15 mRNA levels in oocytes from the Ac-UCP group, regardless of maturation stage, suggesting that the accumulation of the mRNA could be due to potential challenges in translation in the Ac-UCP group. In conclusion, this study challenges the hypothesis that PRP, as a serum source, could improve follicle culture outcomes compared to FBS, the gold standard in murine follicle culture. Further research is needed to understand the species-specific effects of PRP and explore other potential factors affecting follicle culture and oocyte quality.

Ovarian follicle size or growth rate can both be determinants of ovulatory follicle selection in mice†

The endocrinology regulating ovulation of the desired number of oocytes in the ovarian cycle is well described, particularly in mono-ovulatory species. Less is known about the characteristics that make one follicle suitable for ovulation while most other follicles die by atresia. Bromodeoxyuridine (BrdU) injection was used to characterize granulosa cell proliferation rates in developing ovarian follicles in the estrous cycle of mice. This methodology allowed identification of follicle diameters of secondary (80-130 μm), follicle-stimulating hormone (FSH)-sensitive (130-170 μm), FSH-dependent (170-350 μm), and preovulatory (>350 μm) follicles. Few preovulatory-sized follicles were present in the ovaries of mice at estrus, the beginning of the cycle. Progressive increases were seen at metestrus and diestrus, when full accumulation of the preovulatory cohort (~10 follicles) occurred. BrdU pulse-chase studies determined granulosa cell proliferation rates in the 24-48 h before the follicle reached the preovulatory stage. This showed that slow-growing follicles were not able to survive to the preovulatory stage. Mathematical modeling of follicle growth rates determined that the largest follicles at the beginning of the cycle had the greatest chance of becoming preovulatory. However, smaller follicles could enter the preovulatory follicle pool if low numbers of large antral follicles were present at the beginning of the cycle. In this instance, rapidly growing follicles had a clear selection advantage. The developing follicle pool displays heterogeneity in granulosa cell proliferation rates, even among follicles at the same stage of development. This parameter appears to influence whether a follicle can ovulate or become atretic.

Random-start ovarian stimulation in an oocyte donation programme: a large, single-centre, experience

RESEARCH QUESTION

Do live birth rates differ between recipients matched with donors using conventional ovarian stimulation compared with those using random-start protocols?

DESIGN

Retrospective analysis of 891 ovarian stimulations in egg donors (January-December 2018) and clinical outcomes in matched recipients (n = 935). Donors commenced ovarian stimulation on day 1-3 of the menstrual cycle (n = 223) or in the mid/late-follicular (n = 388) or luteal phase (n = 280) under a conventional antagonist protocol. Live birth rate of matched recipients was the main outcome.

RESULTS

Duration of stimulation and total gonadotrophin dose were comparable between conventional versus random-start groups. The number of collected eggs were similar (17.6 ± 8.8 versus 17.2 ± 8.5, P = 0.6, respectively). Sub-group analysis showed that stimulation length (10.2 ± 1.8 versus 9.8 ± 1.7 versus 10.4 ± 1.7, P < 0.001) and gonadotrophin consumption (2041.5 ± 645.3 versus 2003.2 ± 647.3 versus 2158.2 ± 685.7 IU, P = 0.01) differed significantly between the conventional, mid/late follicular and luteal phase groups, respectively. In matched recipients receiving fresh oocytes and undergoing fresh embryo transfer, the biochemical pregnancy (63.8% and 63.3%; P = 0.9), clinical pregnancy (54.6% and 56.1%; P = 0.8) and live birth rates (47.7% and 46.6%; P = 0.7) per embryo-transfer were similar between conventional versus random groups. Similar results were obtained in recipients receiving vitrified eggs. Euploidy rate was also comparable.

CONCLUSIONS

No notable variations were found in clinical outcomes using oocytes obtained from random-start protocols and those proceeding from conventional ovarian stimulation in oocyte donation treatments. Luteal-phase stimulation seems to require longer stimulation and higher FSH consumption. Random-start stimulation strategy does not impair the potential of the oocyte yield or clinical outcomes in oocyte donation cycles.

Identification of long noncoding RNAs downregulated specifically in ovarian high-grade serous carcinoma

Purpose

To investigate whether long noncoding RNAs (lncRNAs) are involved in the development or malignant behavior of ovarian high-grade serous carcinoma (HGSC), we attempted to identify lncRNAs specific to HGSC.

Methods

Total RNAs were isolated from HGSC, normal ovarian, and fallopian tube tissue samples and were subjected to a PCR array that can analyze 84 cancer-associated lncRNAs. The lncRNAs that were upregulated and downregulated in HGSC in comparison to multiple samples of normal ovary and fallopian tube were validated by real-time RT-PCR. To infer the function, ovarian cancer cell lines that overexpress the identified lncRNAs were established, and the activation of cell proliferation, migration, and invasion was analyzed.

Results

Eleven lncRNAs (ACTA2-AS1, ADAMTS9-AS2, CBR3-AS1, HAND2-AS1, IPW, LINC00312, LINC00887, MEG3, NBR2, TSIX, and XIST) were downregulated in HGSC samples. We established the cell lines that overexpress ADAMTS9-AS2, CBR3-AS1, or NBR2. In cell lines overexpressing ADAMTS9-AS2, cell proliferation was suppressed, but migration and invasion were promoted. In cell lines overexpressing CBR3-AS1 or NBR2, cell migration tended to be promoted, although cell proliferation and invasion were unchanged.

Conclusion

We identified eleven lncRNAs that were specifically downregulated in HGSC. Of these, CBR3-AS1, NBR2, and ADAMTS9-AS2 had unique functions in the malignant behaviors of HGSC.

Serum anti-Müllerian hormone concentrations are related to embryo development: lessons from time-lapse imaging

Our objective was to study whether serum anti-Müllerian hormone (AMH) concentrations were associated with embryo morphokinetic events. This retrospective cohort study was performed in a private university-affiliated in vitro fertilization centre between March 2019 and December 2020 and included 902 oocytes cultured in a time-lapse imaging incubator, obtained from 114 intracytoplasmic sperm injection cycles performed. The relationship between AMH concentrations and morphokinetic events was investigated by considering the clustering of data (multiple embryos/patient). Evaluated kinetic markers were time to pronuclei appearance (tPNa) and fading (tPNf), time to two (t2), three (t3), four (t4), five (t5), six (t6), seven (t7), and eight cells (t8), (tSB) and time to the start of blastulation (tSB) and to blastulation (tB). Significant inverse relationships were observed between serum AMH concentrations and tPNf, t3, t4, t5, t6, t7, t8, and tB. The AMH was positively correlated with the KIDScore and implantation rate. Increased serum AMH concentrations correlated with faster embryo development. The clinical implications of this effect on embryo development warrant further investigation.

Random start ovarian stimulation before gonadotoxic therapies in women with cancer: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to quantify the effect of random start ovarian stimulation (RSOS) compared with conventional start ovarian stimulation (CSOS) in cancer patients before gonadotoxic treatment. The final analytical cohort encompassed 688 RSOS and 1076 CSOS cycles of cancer patients before gonadotoxic treatment. Eleven studies were identified by database searches of MEDLINE, Cochrane Library and cited references. The primary outcomes of interest were the number of oocytes and mature oocytes collected, the number of embryos cryopreserved and the metaphase II (MII)-antral follicle count (AFC) ratio. The studies were rated from medium to high quality (from 6 to 9) according to the Newcastle-Ottawa Quality Assessment Scale. The two protocols resulted in similar numbers of oocytes collected, MII oocytes, embryos available for cryopreservation and comparable MII-AFC and fertilization rates. The duration of ovarian stimulation was longer (standardized mean difference [SMD] 0.35, 95% CI 0.09 to 0.61; P = 0.009) and gonadotrophin consumption was higher (SMD 0.23, 95% CI 0.06 to 0.40; P = 0.009) in RSOS compared with CSOS. This systematic review and meta-analysis show that the duration of stimulation is longer, and the total gonadotrophin consumption is higher in cancer patients undergoing RSOS compared with those undergoing CSOS, with no significant effect on mature oocyte yield.

Classification of Atretic Small Antral Follicles in the Human Ovary

The reproductive lifespan in humans is regulated by a delicate cyclical balance between follicular recruitment and atresia in the ovary. The majority of the small antral follicles present in the ovary are progressively lost through atresia without reaching dominance, but this process remains largely underexplored. In our study, we investigated the characteristics of atretic small antral follicles and proposed a classification system based on molecular changes observed in granulosa cells, theca cells, and extracellular matrix deposition. Our findings revealed that atresia spreads in the follicle with wave-like dynamics, initiating away from the cumulus granulosa cells. We also observed an enrichment of CD68+ macrophages in the antrum during the progression of follicular atresia. This work not only provides criteria for classifying three stages of follicular atresia in small antral follicles in the human ovary but also serves as a foundation for understanding follicular degeneration and ultimately preventing or treating premature ovarian failure. Understanding follicular remodeling in the ovary could provide a means to increase the number of usable follicles and delay the depletion of the follicular reserve, increasing the reproductive lifespan.

Using Quantitative Hormone Monitoring to Identify the Postpartum Return of Fertility

Background and Objectives: The Marquette Method (MM) has been used for many years to track the postpartum return of fertility using the ClearBlue Fertility Monitor (CBFM). A new quantitative urine hormone monitor (the Mira Analyzer) was compared to the CBFM in one previous study, and using this pilot data, several women have started to use the Mira Analyzer in the postpartum transition to fertility. Materials and Methods: This study was a retrospective, observational case series that analyzed hormone data on the Mira Analyzer during the postpartum period. Participants were invited to share their postpartum cycle and hormone observations. Quantitative hormones in the urine included estrone-3-glucuronide (E3G), luteinizing hormone (LH), and pregnanediol glucuronide (PDG). Data were collected using an electronic survey and an online portal for hormone data. Data collected included participant demographics, menstrual cycle characteristics, and reproductive health history. Hormone range values were calculated, and thresholds were identified that would best predict the first ovulation that led to the first postpartum menstrual period, as well as in transition cycles. Hormone patterns were identified in the context of previous studies. Results: Twenty participants contributed data for the analysis. Triggering ovulation before the first period postpartum (Cycle 0) usually required higher LH thresholds than for regularly cycling women. Three different patterns were observed in the return of fertility postpartum: minimal ovarian activity, follicular activity without ovulation, and the early return of fertility. Abstinence rates for avoiding pregnancy with experimental thresholds were calculated. Conclusions: Higher LH thresholds in Cycle 0 suggest a decreased responsiveness of the ovaries to LH stimulation from the pituitary. This study replicates postpartum hormone patterns from a previous study. Larger studies are planned to evaluate the effectiveness for avoiding pregnancy using the Mira Analyzer in the postpartum return of fertility.

Outcomes and cost-effectiveness comparisons of progestin-primed ovarian stimulation, GnRH antagonist protocol, and luteal phase stimulation for fertility preservation

OBJECTIVE

To compare the clinical outcomes and cost-effectiveness of progestin-primed ovarian stimulation (PPOS) and the gonadotropin-releasing hormone-antagonist (GnRH-A) protocol in fertility preservation (FP) in cancer patients. The stimulation option when patients were in the luteal phase was also explored.

METHODS

This retrospective study analyzed clinical data from 163 patients who underwent FP. The number of retrieved oocytes and vitrified oocytes/embryos, total dose of gonadotropin, duration of stimulation, number of injections, and cost were compared among the PPOS, GnRH-A, and luteal phase stimulation (LPS) groups.

RESULTS

No significant differences were noted in the numbers of retrieved oocytes and vitrified oocytes/embryos among the three groups. In the multiple regression model, age (P = 0.02) and antral follicle count (AFC) (P < 0.001), but not the controlled ovarian stimulation (COS) protocols (P = 0.586), were associated with the number of retrieved oocytes. The number of injections and the cost were all significantly lower in the PPOS and LPS groups than in the GnRH-A group(P < 0.001).

CONCLUSION

PPOS had similar clinical results but was superior medically and economically to GnRH-A. For patients in the luteal phase, LPS was an optional protocol with similar outcomes and costs to PPOS.

β-Nicotinamide Mononucleotide Alleviates Hydrogen Peroxide-Induced Cell Cycle Arrest and Death in Ovarian Granulosa Cells

Maintaining normal functions of ovarian granulosa cells (GCs) is essential for oocyte development and maturation. The dysfunction of GCs impairs nutrition supply and estrogen secretion by follicles, thus negatively affecting the breeding capacity of farm animals. Impaired GCs is generally associated with declines in Nicotinamide adenine dinucleotide (NAD+) levels, which triggers un-controlled oxidative stress, and the oxidative stress, thus, attack the subcellular structures and cause cell damage. β-nicotinamide mononucleotide (NMN), a NAD+ precursor, has demonstrated well-known antioxidant properties in several studies. In this study, using two types of ovarian GCs (mouse GCs (mGCs) and human granulosa cell line (KGN)) as cell models, we aimed to investigate the potential effects of NMN on gene expression patterns and antioxidant capacity of both mGCs and KGN that were exposed to hydrogen peroxide (H2O2). As shown in results of the study, mGCs that were exposed to H2O2 significantly altered the gene expression patterns, with 428 differentially expressed genes (DEGs) when compared with those of the control group. Furthermore, adding NMN to H2O2-cultured mGCs displayed 621 DEGs. The functional enrichment analysis revealed that DEGs were mainly enriched in key pathways like cell cycle, senescence, and cell death. Using RT-qPCR, CCK8, and β-galactosidase staining, we found that H2O2 exposure on mGCs obviously reduced cell activity/mRNA expressions of antioxidant genes, inhibited cell proliferation, and induced cellular senescence. Notably, NMN supplementation partially prevented these H2O2-induced abnormalities. Moreover, these similar beneficial effects of NMN on antioxidant capacity were confirmed in the KGN cell models that were exposed to H2O2. Taken together, the present results demonstrate that NMN supplementation protects against H2O2-induced impairments in gene expression pattern, cell cycle arrest, and cell death in ovarian GCs through boosting NAD+ levels and provide potential strategies to ameliorate uncontrolled oxidative stress in ovarian GCs.

Potential factors result in diminished ovarian reserve: a comprehensive review

The ovarian reserve is defined as the quantity of oocytes stored in the ovary or the number of oocytes that can be recruited. Ovarian reserve can be affected by many factors, including hormones, metabolites, initial ovarian reserve, environmental problems, diseases, and medications, among others. With the trend of postponing of pregnancy in modern society, diminished ovarian reserve (DOR) has become one of the most common challenges in current clinical reproductive medicine. Attributed to its unclear mechanism and complex clinical features, it is difficult for physicians to administer targeted treatment. This review focuses on the factors associated with ovarian reserve and discusses the potential influences and pathogenic factors that may explain the possible mechanisms of DOR, which can be improved or built upon by subsequent researchers to verify, replicate, and establish further study findings, as well as for scientists to find new treatments.

Making a good egg: human oocyte health, aging, and in vitro development

Mammalian eggs (oocytes) are formed during fetal life and establish associations with somatic cells to form primordial follicles that create a store of germ cells (the primordial pool). The size of this pool is influenced by key events during the formation of germ cells and by factors that influence the subsequent activation of follicle growth. These regulatory pathways must ensure that the reserve of oocytes within primordial follicles in humans lasts for up to 50 years, yet only approximately 0.1% will ever be ovulated with the rest undergoing degeneration. This review outlines the mechanisms and regulatory pathways that govern the processes of oocyte and follicle formation and later growth, within the ovarian stroma, through to ovulation with particular reference to human oocytes/follicles. In addition, the effects of aging on female reproductive capacity through changes in oocyte number and quality are emphasized, with both the cellular mechanisms and clinical implications discussed. Finally, the details of current developments in culture systems that support all stages of follicle growth to generate mature oocytes in vitro and emerging prospects for making new oocytes from stem cells are outlined.

Ovarian reserve in patients with multiple sclerosis: A systematic review and meta-analysis

OBJECTIVE

To summarize recent evidence about ovarian reserve markers in women affected by multiple sclerosis (MS) compared with healthy controls, as women with MS seem to be characterized by lower anti-Müllerian hormone (AMH) levels.

METHODS

The research was conducted using PubMed (MEDLINE), Scopus, ClinicalTrial.gov, OVID and Cochrane Library from inception of each database to June 30, 2022. Studies comparing ovarian reserve markers between women with MS and healthy controls were considered eligible for inclusion. The primary outcome was serum AMH (ng/mL) levels. Results were reported as pooled odds ratio (OR) for categorical outcomes and as mean difference (MD) for continuous variables, with their 95% confidence intervals (CIs). The random effect model of DerSimonian and Laird was adopted for all analyses. A P-value less than 0.05 was considered significant.

RESULTS

Serum AMH circulating levels were not significantly different (MD -0.25, 95% CI -0.83 to 0.32; P = 0.390), as well as blood levels of follicle-stimulating hormone or ovarian volume. However, antral follicle count (AFC) and estradiol blood levels were significantly lower, and luteinizing hormone (LH) levels were significantly higher in women with MS than in controls.

CONCLUSION

A significant difference in AFC, estradiol and LH levels was observed, but not for AMH levels.

Improving Cryopreservation Efficiency and Pregnancy Rate through Superovulation with Follicle-Stimulating Hormone in Korean Hanwoo Cows via Ovum Pick Up

The aim of this study was to devise an efficient technique for generating embryos from high-quality bovine females. Oocytes were collected from 20 control and 15 Hanwoo (Bos taurus coreanae) females treated with the FSH. A combination of decreasing FSH doses (36, 36, 24, and 24 mg, 12 h apart), progesterone, estrogen, and prostaglandins were administered to synchronize and mildly stimulate the animals. The FSH-treated group (1125 oocytes) and control group (1022 oocytes) exhibited a higher proportion of grade A and B oocytes (88.2%) than the other grades (p < 0.05), with most at the germinal vesicle 2 stage (64.0%). Moreover, the FSH-treated group achieved a notably higher blastocyst rate (44.7%) compared to the control group (31.1%) (p < 0.05). After undergoing vitrification and in vitro culture (IVC) warming, embryos in the FSH group exhibited higher re-expansion rates (grade 1: 86.9%; grades 2 and 3: 57.9%) compared to those in the control (p < 0.05). This highlights the positive impact of FSH treatment on in vitro embryo production (IVEP) and the OPU rate.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

Predicting the total number of retrieved oocytes following double ovarian stimulation (DuoStim)

STUDY QUESTION

Can anti-Müllerian hormone (AMH) help predict how many oocytes will be retrieved following double stimulation (DuoStim)?

SUMMARY ANSWER

A simple clinical tool can use serum AMH values to predict ovarian response following DuoStim in IVF cycles.

WHAT IS ALREADY KNOWN

The knowledge that multiple follicular waves arise during a single ovarian cycle has led to the introduction of unconventional ovarian stimulation protocols. The DuoStim protocol involves two successive ovarian stimulations performed during a single ovarian cycle and has been proposed as an approach for patients with poor ovarian response and for medical fertility preservation. As AMH has been used as a marker of ovarian reserve and stimulation response, the current study aimed to investigate the diagnostic performance of AMH in predicting the number of retrieved oocytes following DuoStim.

STUDY DESIGN, SIZE, DURATION

This is a retrospective observational study involving 116 patients who received IVF treatment from January 2021 to September 2022.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted at a private IVF centre. Only patients who had their AMH measured prior to treatment and had complete patient records regarding their clinical and IVF/ICSI cycle characteristics were included. The primary outcome was the correlation between AMH values and the number of oocytes retrieved following DuoStim. Parametric and non-parametric tests were used to compare baseline characteristics and outcomes. Spearman's R was used to analyse correlations between variables, while the C statistic was used to calculate the diagnostic performance of AMH.

MAIN RESULTS AND THE ROLE OF CHANCE

AMH levels were significantly correlated with the total number of oocytes retrieved after the DuoStim (R 0.61; CI 0.44-0.70; P < 0.0001). The difference in the total number of oocytes retrieved between the first (median 4 oocytes, interquartile range (IQR) 2-6) and second (median 6 oocytes, IQR 3.2-8) stimulation was statistically significant (P < 0.0001). However, there was no significant difference in the number of mature oocytes that were retrieved (median of 3 and 4 in the first and second stimulations, respectively). After the first stimulation, 68% of patients had at least one blastocyst available, while after the second stimulation, 74% did (NS). Based on linear regression, each 0.25 ng/ml increase in basal AMH corresponds to one additional oocyte recovered at the end of both stimulations (R2: 0.32, P < 0.0001).

LIMITATIONS, REASONS FOR CAUTION

The results are limited owing to the observational nature of the study and the number of participants.

WIDER IMPLICATIONS OF THE FINDINGS

Counselling infertile couples regarding the intermediate outcome of IVF (i.e. number of retrieved oocytes) is one of the most demanding tasks that clinicians face. To our knowledge, this is the first study that provides an easy-to-use clinical tool that enables the quantitative prediction of ovarian response following DuoStim, based on serum AMH values.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was obtained for this study. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Rescue of bmp15 deficiency in zebrafish by mutation of inha reveals mechanisms of BMP15 regulation of folliculogenesis

As an oocyte-specific growth factor, bone morphogenetic protein 15 (BMP15) plays a critical role in controlling folliculogenesis. However, the mechanism of BMP15 action remains elusive. Using zebrafish as the model, we created a bmp15 mutant using CRISPR/Cas9 and demonstrated that bmp15 deficiency caused a significant delay in follicle activation and puberty onset followed by a complete arrest of follicle development at previtellogenic (PV) stage without yolk accumulation. The mutant females eventually underwent female-to-male sex reversal to become functional males, which was accompanied by a series of changes in secondary sexual characteristics. Interestingly, the blockade of folliculogenesis and sex reversal in bmp15 mutant could be partially rescued by the loss of inhibin (inha-/-). The follicles of double mutant (bmp15-/-;inha-/-) could progress to mid-vitellogenic (MV) stage with yolk accumulation and the fish maintained their femaleness without sex reversal. Transcriptome analysis revealed up-regulation of pathways related to TGF-β signaling and endocytosis in the double mutant follicles. Interestingly, the expression of inhibin/activin βAa subunit (inhbaa) increased significantly in the double mutant ovary. Further knockout of inhbaa in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-) resulted in the loss of yolk granules again. The serum levels of estradiol (E2) and vitellogenin (Vtg) both decreased significantly in bmp15 single mutant females (bmp15-/-), returned to normal in the double mutant (bmp15-/-;inha-/-), but reduced again significantly in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-). E2 treatment could rescue the arrested follicles in bmp15-/-, and fadrozole (a nonsteroidal aromatase inhibitor) treatment blocked yolk accumulation in bmp15-/-;inha-/- fish. The loss of inhbaa also caused a reduction of Vtg receptor-like molecules (e.g., lrp1ab and lrp2a). In summary, the present study provided comprehensive genetic evidence that Bmp15 acts together with the activin-inhibin system in the follicle to control E2 production from the follicle, Vtg biosynthesis in the liver and its uptake by the developing oocytes.

Ovarian stimulation and oocyte cryopreservation in females with cancer

PURPOSE OF REVIEW

We reviewed the most recent developments including the safety and effectiveness data and success rates in individualized ovarian stimulation protocols for adult and postpubertal females with cancer.

RECENT FINDINGS

In women with breast cancer, aromatase inhibitor- and tamoxifen-supplemented stimulation protocols increase the margin of safety by limiting estrogen exposure. The outcomes of ovarian stimulation appear similar between cancer and noncancer populations, even with the recently developed random-start protocols, which allow initiation of ovarian stimulation anytime during the menstrual cycle. Based on lower anti-Mullerian hormone levels and primordial follicle density, carriers of BRCA pathogenic variants ( BRCApv ) have decreased ovarian reserve in comparison to women without those variants and may lose larger portion of their ovarian reserve post chemotherapy. Oocyte cryopreservation is also emerging as a suitable fertility preservation approach for selected postpubertal girls as young as 12 years of age.

SUMMARY

Individualized ovarian stimulation approaches combined with improvements in cryopreservation techniques increased the success and safety margin to preserve fertility with oocyte freezing. Women with BRCApv , on the other hand, may be at disadvantage as they have lower ovarian reserve and may lose larger portion of their ovarian reserve post chemotherapy compared to women who do not carry these variants.

Establishing a Gold Standard for Quantitative Menstrual Cycle Monitoring

Background and Objectives: The Quantum Menstrual Health Monitoring Study will measure four key reproductive hormones in the urine (follicle-stimulating hormone, FSH; estrone-3-glucuronide, E13G; luteinizing hormone, LH; and pregnanediol glucuronide, PDG) to characterize patterns that predict and confirm ovulation, referenced to serum hormones and the gold standard of the ultrasound day of ovulation in participants with regular cycles. These normal cycles will provide a reference for comparison to irregular cycles in subjects with polycystic ovarian syndrome (PCOS) and athletes. Materials and Methods: Participants will track their menstrual cycles for 3 months and be provided with an at-home urine hormone monitor (Mira monitor) to predict ovulation. The day of ovulation will be confirmed with serial ultrasounds completed in a community clinic. Urine results will be compared to serum hormone values. Other markers of menstrual health, such as bleeding patterns and temperature changes, will be determined using a customized app. Three groups will be recruited. Group 1 will include those with consistent regular cycle lengths (between 24-38 days), and will be compared to two groups with irregular cycle lengths (with increased cycle length variability and longer cycles). Group 2 will include those with polycystic ovarian syndrome (PCOS) with irregular cycles and Group 3 will include individuals participating in high levels of exercise with irregular cycles. Hypothesis: The Mira monitor quantitative urine hormone pattern will accurately correlate with serum hormonal levels and will predict (with LH) and confirm (with PDG) the ultrasound day of ovulation in those with regular cycles as well as those with irregular cycles. Rationale: Once the ultrasound validation is complete, tools like the Mira monitor with a customized app may become a new standard for at-home and remote clinical monitoring of the menstrual cycle without having to use labor-intensive follicular-tracking ultrasound or follow serum hormone changes. Conclusions: Precision monitoring of the menstrual cycle is expected to impact individuals who want to increase their menstrual health literacy and guide decisions about fertility.

Ovarian aging in humans: potential strategies for extending reproductive lifespan

Ovarian reserve is a term used to estimate the total number of immature follicles present in the ovaries. Between birth and menopause, there is a progressive decrease in the number of ovarian follicles. Ovarian aging is a continuous physiological phenomenon, with menopause being the clinical mark of the end of ovarian function. Genetics, measured as family history for age at the onset of menopause, is the main determinant. However, physical activity, diet, and lifestyle are important factors that can influence the age of menopause. The low estrogen levels after natural or premature menopause increased the risk for several diseases, resulting in increased mortality risk. Besides that, the decreasing ovarian reserve is associated to reduced fertility. In women with infertility undergoing in vitro fertilization, reduced markers of ovarian reserve, including antral follicular count and anti-Mullerian hormone, are the main indicators of reduced chances of becoming pregnant. Therefore, it becomes clear that the ovarian reserve has a central role in women's life, affecting fertility early in life and overall health later in life. Based on this, the ideal strategy for delaying ovarian aging should have the following characteristics: (1) be initiated in the presence of good ovarian reserve; (2) maintained for a long period; (3) have an action on the dynamics of primordial follicles, controlling the rate of activation and atresia; and (4) safe use in pre-conception, pregnancy, and lactation. In this review, we therefore discuss some of these strategies and its feasibility for preventing a decline in the ovarian reserve.

Influence of the starting day of luteal phase stimulation on double stimulation cycles

Background

Double ovarian stimulation is one of the most used strategies in poor-prognosis patients. There is a high heterogeneity between the studies regarding the execution of this stimulation protocol. The aim of this study was to investigate whether the day on which luteal phase stimulation begins after the first oocyte retrieval affects ovarian response in DuoStim cycles.

Methods

This observational and retrospective study included 541 DuoStim cycles between January 2018 and December 2021 in a private fertility clinic. Patients were assigned to 4 groups according to the timing of the onset of luteal phase stimulation after oocyte retrieval (0-2^nd day, 3^rd day, 4^th day and 5^th-6^th day). The primary outcome was the number of oocytes retrieved in the luteal phase in each group.

Results

No differences were found between groups in the number of oocytes collected (5.12 ± 3.56 vs. 5.39 ± 3.74 vs. 5.61 ± 3.94 vs. 5.89 ± 3.92; p=0,6), MII or number of follicles. An increase in the duration of stimulation was found when stimulation started on the 4^th day (10.42 ± 2.31 vs. 10.68 ± 2.37 vs. 11.27 ± 2.40 vs. 10.65 ± 2.37 days, p=0,033). A lower number of fertilized oocytes was observed when stimulation began before the fourth day (3.36 ± 2.80 vs. 3.95 ± 2.53 vs. 4.03 ± 2.73 vs. 4.48 ± 3.11; p=0,036). The number of blastocysts was higher when the stimulation started 5-6 days after retrieval (1.82 ± 1.74 vs. 2.13 ± 1.61 vs. 2.33 ± 2.06 vs. 2.91 ± 2.39; p= 0,030).

Discussion

The number of oocytes retrieved does not differ depending on the day that stimulation begins. However, oocytes competence in terms of fertilized oocytes and blastulation, appears to be lower when the second stimulation starts before the fourth day after oocyte retrieval.

Luteal Phase Stimulation in the Same Cycle Is an Effective Strategy to Rescue POSEIDON Poor Responders with No Embryos after the First Follicular Stimulation

Background

Poor responders may benefit from recruiting a 'second wave' of antral follicles within the same cycle. This concept forms the basis of double stimulation which has been named as 'DuoStim'. This protocol involves ovarian stimulation in both follicular and luteal phases with egg retrieval in each phase, respectively, to increase the number of oocytes and embryos in one menstrual cycle. This can be considered a potentially valuable option for women with poor ovarian reserve/response to maximise the number of oocytes retrieved in a single ovarian cycle in the shortest possible time.

Aims

The aim of this study was to evaluate the efficacy of the DuoStim protocol in women classified as POSEIDON poor responders undergoing in vitro fertilization by comparing the embryological outcomes between the follicular and luteal phase stimulations in the same menstrual cycle.

Settings and Design

This was a retrospective cohort study of 131 patients who enrolled to undergo DuoStim cycles from January 2021 to Sept. 2022, at a IVF center in a tertiary care hospital.

Materials and Methods

The follicular phase stimulation used a standard antagonist protocol for the first oocyte retrieval. Thereafter, the luteal phase stimulation was started 3 days after the first retrieval, with the same dose of gonadotropin along with a daily 10 mg medroxyprogesterone acetate tablet, followed by a second oocyte retrieval. Blastocysts produced in both the phases were subsequently vitrified.

Statistical Analysis Used

The paired t-test was used for comparing means and 95% confidence intervals (CIs) for different parameters. McNemar's test was used to compare paired proportions. The analysis was conducted using R statistical environment 4.2.

Results

The mean number of oocytes retrieved and the mean number of utilizable blastocysts frozen per stimulation cycle were found to be significantly higher in the luteal phase as compared to the follicular phase (5.71 ± 3.95 vs. 4.87 ± 2.79, P = 0.02, and 1.43 ± 1.22 vs. 0.95 ± 1, P = 0.001, respectively). However, the mean fertilization rate and the mean blastocyst utilization rate were found to be similar between both the phases. The length of stimulation was found to be approximately 3 days longer in the luteal phase (12.63 ± 2.43 vs. 9.75 ± 1.85, P = 0.001). Overall, the odds of obtaining a usable blastocyst in the luteal phase was found to be significantly higher than in the paired follicular phase (73.9% vs. 57.7%, P = 0.012, odds ratio: 2.286 [95% CI: 1.186-4.636]). Also importantly, the luteal phase stimulation was able to rescue 68% (32/47) of patients where no blastocysts were formed in the follicular phase.

Conclusion

Our data demonstrate that in women with poor reserve, the addition of luteal stimulation could increase the chances of achieving a pregnancy by significantly increasing the number of eggs and transferable embryos per menstrual cycle compared to follicular stimulation alone. Furthermore, luteal phase stimulation in the same cycle proved to be an effective strategy to rescue POSEIDON poor responders with no embryos after the first stimulation.

The menstrual distress questionnaire (MEDI-Q): reliability and validity of the English version

BACKGROUND

Menstrual cycle has a significant impact on women's health from different perspectives, both physically and psychologically. The assessment of menstrual-related distress is of pivotal clinical interest, especially in women with chronic exposure to abnormal bleeding or pain. The Menstrual Distress Questionnaire (MEDI-Q) is a new tool originally developed in Italian that comprehensively evaluates menstrual-related distress.

OBJECTIVE

To validate the English version of the MEDI-Q in an English-speaking population.

METHODS

The study consisted of two phases: an initial translation phase of the original Italian version of the MEDI-Q, and a data collection phase to validate the new English version among 288 native English-speaking women.

RESULTS

The English version of MEDI-Q showed excellent psychometric properties, with high internal consistency (Cronbach's alpha = 0.84) and test-retest reliability (intraclass correlation coefficient = 0.95). Construct validity was supported by significant correlations between MEDI-Q scores and scores on measures of psychological distress and premenstrual symptoms.

CONCLUSIONS

The English version of the MEDI-Q is a valid and reliable instrument for the assessment of menstrual distress and its impact on psychological well-being. This tool can be utilized in research and clinical settings to comprehensively investigate the impact of menstruation on various populations, identify and monitor menstruation-related disorders promptly and effectively, and to evaluate the effectiveness of targeted treatments for menstrual distress.

Inhibition of phosphodiesterase PDE8B reduces activation of primordial follicles in mouse ovaries

In the ovaries, cyclic adenosine 3',5'-monophosphate (cAMP) is a second messenger supporting the generation of steroids. Phosphodiesterases (PDEs) are regulators of intracellular cAMP, and therefore, potential regulators of ovarian function. Interestingly, the family of PDE genes are differentially expressed in human oocytes and granulosa cells from primordial and primary follicles, suggesting diverse roles. In this study, we addressed the functions of PDE3B and PDE8B in primordial follicle regulation using inhibitors of PDE3B and PDE8B in murine ovary primary in vitro cultures. Inhibition of PDE8B in ovarian cultures prevented primordial follicle activation, while inhibition of PDE3B had no effect on follicle distribution in the ovary, under the tested conditions. As cAMP levels may increase steroid levels, we assessed the protein levels of the steroidogenic acute regulatory protein (StAR) and aromatase enzymes, and found that inhibition of PDE3B reduced StAR protein levels, whereas inhibition of PDE8 did not alter StAR expression in our murine ovary culture system conditions. Our results showed that ketotifen-induced inhibition of PDE8B can decrease primordial follicle activation, whereas we observed no effect of follicle distribution, when PDE3B was inhibited. Expression of the StaR enzyme was not altered when PDE8B was inhibited, which might reflect not sufficient inhibition by ketotifen to induce StAR alterations, or redundant mechanisms.

Current progress on in vitro differentiation of ovarian follicles from pluripotent stem cells

Mammalian female reproduction requires a functional ovary. Competence of the ovary is determined by the quality of its basic unit-ovarian follicles. A normal follicle consists of an oocyte enclosed within ovarian follicular cells. In humans and mice, the ovarian follicles are formed at the foetal and the early neonatal stage respectively, and their renewal at the adult stage is controversial. Extensive research emerges recently to produce ovarian follicles in-vitro from different species. Previous reports demonstrated the differentiation of mouse and human pluripotent stem cells into germline cells, termed primordial germ cell-like cells (PGCLCs). The germ cell-specific gene expressions and epigenetic features including global DNA demethylation and histone modifications of the pluripotent stem cells-derived PGCLCs were extensively characterized. The PGCLCs hold potential for forming ovarian follicles or organoids upon cocultured with ovarian somatic cells. Intriguingly, the oocytes isolated from the organoids could be fertilized in-vitro. Based on the knowledge of in-vivo derived pre-granulosa cells, the generation of these cells from pluripotent stem cells termed foetal ovarian somatic cell-like cells was also reported recently. Despite successful in-vitro folliculogenesis from pluripotent stem cells, the efficiency remains low, mainly due to the lack of information on the interaction between PGCLCs and pre-granulosa cells. The establishment of in-vitro pluripotent stem cell-based models paves the way for understanding the critical signalling pathways and molecules during folliculogenesis. This article aims to review the developmental events during in-vivo follicular development and discuss the current progress of generation of PGCLCs, pre-granulosa and theca cells in-vitro.

Double stimulation for the management of poor-prognosis patients: where are we going?

PURPOSE OF REVIEW

The technical improvements in IVF allowed the implementation of nonconventional ovarian stimulation protocols for some specific patients. Where time is crucial, such as with oncologic patients, poor-prognosis patients, patients with low ovarian reserve, and those with advanced maternal age, access to IVF treatment is even more critical. Some of these protocols might start in the late follicular phase, luteal phase, or involve both stimulations within the same ovarian cycle.

RECENT FINDINGS

Until now, published evidence showed that oocytes retrieved from unconventional protocol seem to be developmentally, genetically, and reproductively competent. Second stimulation in the same ovarian cycle after the conventional approach may represent a sound alternative to oocyte accumulation. This can be proposed in progress after careful counselling focused on the patients' chances of finding at least one euploid embryo on account of their age and of the number of blastocysts obtained after the conventional approach.

SUMMARY

The adoption of these new strategies, known as double stimulation protocol, can be conceived as a real full-personalization of ovarian stimulation. Multicentre prospective RCTs are urgently needed to evaluate the efficacy, efficiency, and costs of double stimulation versus two consecutive conventional approaches with standard or mild stimulation and in a different IVF setting.

miR-200b/MYBL2/CDK1 suppresses proliferation and induces senescence through cell cycle arrest in ovine granulosa cells

Normal growth of granulosa cells (GCs) is essential for follicular development. miR-200b plays a vital role in litter size, estrous cycle, ovulation, and follicular development in sheep. However, it is unclear that the specific effect and regulatory mechanism of miR-200b on ovine GCs. miR-200b mimic inhibited GCs proliferation and induced cellular senescence through downregulating mitochondrial membrane potential (MMP), concentration of ATP and mitochondrial respiratory chain complex Ⅰ, and upregulating SA-β-gal positive rate and ROS production. A total of 597 differentially expressed genes were identified by RNA-Seq in GCs transfected with miR-200b mimic and mimic NC, and they were involved in cell cycle and cellular senescence. miR-200b directly targeted and downregulated MYBL2 and CDK1. Overexpression of MYBL2 promoted GCs proliferation and genes expression (CDK1, CDC20, MAD2L1 and FOXM1), which were suppressed by miR-200b mimic. Furthermore, MYBL2 negatively regulated miR-200b-induced GC senescence. In conclusion, miR-200b/MYBL2/CDK1 regulated proliferation and senescence through cell cycle pathway in ovine granulosa cells. Our study provides a novel insight that miR-200b regulates ovine follicular development.

Ferredoxin 1 regulates granulosa cell apoptosis and autophagy in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a common reproductive endocrine disorder in women of reproductive age, causes anovulatory infertility. Increased apoptosis of granulosa cells has been identified as one of the key factors contributing to abnormal follicular development. Ferredoxin 1 (FDX1) encodes a small ferredoxin that is involved in the reduction in mitochondrial cytochromes and the synthesis of various steroid hormones and has the potential to influence the function of granulosa cells. In the present study, we aimed to determine the relationship between FDX1 and follicular granulosa cell function. To this end, we investigated the difference between FDX1 expression in the granulosa cells of 50 patients with PCOS and that of the controls. Furthermore, we sought to elucidate the role and mechanism of FDX1 in PCOS granulosa cells by establishing a mouse PCOS model with dehydroepiandrosterone and KGN (a steroidogenic human granulosa cell-like tumor cell line). The results indicated significant up-regulation of FDX1 in the granulosa cells after androgen stimulation. Knockdown of FDX1 promoted the proliferation of KGN and inhibited apoptosis. Moreover, FDX1 could regulate autophagy by influencing the autophagy proteins ATG3 and ATG7. Our results demonstrated that FDX1 plays a critical role in female folliculogenesis by mediating apoptosis, autophagy, and proliferation. Therefore, FDX1 may be a potential prognostic factor for female infertility.