Follicular Oocytes Research Articles

The administration of GnRH and HCG: double trigger vs HCG alone for follicular oocyte maturation in poor IVF responders—a randomized controlled trial

BackgroundIn vitro fertilization (IVF) has revolutionized human reproduction. Originally designed to assist couples who are unable to conceive, the clinical applications of IVF have significantly broadened to encompass many medical and genetic disorders, as well as fertility maintenance. The poor ovarian response is a very challenging issue in the field of infertility, “double triggering” combines a single bolus of gonadotropic releasing hormone (GnRH)-agonist with a standard dosage of human chorionic gonadotropin (HCG) at the time of triggering has been proposed that it improves the outcomes in poor responders.MethodsTo study this effect, 73 POR patients received 10,000 units of HCG plus 0.2 mg of GnRH-agonist for ovulation triggering (study group) after induction of ovulation using antagonist protocol, while other 73 POR patients received standard dosage of HCG trigger (10,000 units of HCG) (control group) after the same IOO settings.ResultsOur results showed that the study group had a higher number of retrieved Metaphase II oocytes, fertilized oocytes, and number of embryos obtained, than the control group. This difference was statistically significant (P-value < 0.05). Other outcomes like chemical and clinical pregnancy rates were also higher in the study group than in the control group, but this difference was not statistically significant (P-value 0.322 and 0.355, respectively).ConclusionThese findings demonstrated that the use of a double trigger with GnRH agonist and HCG, compared to HCG alone, leads to improved outcomes in poor responder IVF patients. Subsequently, the double-trigger protocol may be a beneficial approach for optimizing outcomes in IVF patients with POR.

Effect of Hormones, Season and Lactation on Follicular Size, Oocyte Competency and Embryo Production in Sahiwal Cattle

Background: Transvaginal ultrasound-guided ovum pick-up (OPU) and in vitro embryo production (IVEP) techniques are widely used for enhancing reproductive efficiency. The number and quality of embryos have been reported to be influenced by various factors like source of hormones, season, lactation in cattle. Methods: Twenty-one multiparous, normal cyclic Sahiwal cows (aged: 6-8 years; lactating: n-11 and non-lactating: n-10) were selected randomly and the experiment was conducted during hot (April to September) and cold (October to March) seasons. All the donor cows were administered 10 µg GnRH at random stage of oestrous cycle followed by FSH (Folltropin-V™ or Stimufol) at the rate of 100, 60 and 40 mg after 48, 60 and 72 h of GnRH administration. After 24 hours of coasting period, follicular aspiration was performed by stabilizing the targeted follicles with the help of ultrasonography. The procedures of COCs grading, in vitro maturation, fertilization, followed by culture were performed as per the standard protocols. Results: The hormonal treatment was effective in improving the oocytes’ developmental competency and in vitro embryo production; with no statistical differences between the two sources. The follicle size distribution revealed a lower (P less than 0.05) medium-sized and small-sized follicular proportion during the hot season with a higher average count of dominant (large-sized) follicles. While, good quality (A+B+C) oocytes, matured and fertilized oocytes were significantly higher (P less than 0.05) in non-lactating donors, especially among cool-season collections.

High-altitude hypoxia exposure alters follicular metabolome and oocyte developmental potential in women.

To explore the effects of high-altitude hypoxia on the microenvironment of oocyte development and fertilization potential, we compared the metabolomic patterns of follicular fluid from women living in different altitude areas and traced their oocyte maturation and subsequent development. A total of 315 clinical cases were collected and divided into three groups according to their residence altitudes: 138 cases in low-altitude (< 2300m) group, 100 cases in middle-altitude (2300-2800m) group and 77 cases in high-altitude (> 2800m) group. The clinical outcomes were statistically estimated, including hormonal level, oocyte maturation, in vitro fertilization, and embryo development. Meanwhile, a metabolomic analysis was performed on the follicular fluid of women from different groups using ultra-high-performance liquid chromatography and high-resolution mass spectrometry and differential metabolites were analyzed through the KEGG pathway. The clinical data indicated that the physical condition and reproductive hormone secretion were similar among different groups. Although personalized gonadotropin-releasing hormone strategies were applied, the numbers of antral follicles and obtained oocytes were not impacted by the residence altitude change. In in vitro culture, the maturing rate, fertility rate and cleavage rate of high-altitude group were compared with the other groups. However, the rates of high-quality embryo, formative blastocyst, and available blastocyst were gradually decreased with the rise of residence altitude. Metabolome analysis identified 1193 metabolites in female follicular fluid. Differential analysis indicated that metabolic components in follicular fluid were remarkably changed with the elevation of residence altitude. These differential metabolites were closely related with amino acid metabolism, protein digestion and absorption, oocyte meiosis and steroid biosynthesis. The residence altitude alters the microenvironment of follicular fluid, which could damage the oocyte developmental potential. This study provides diagnostic basis and therapeutic targets for research on female oocyte and embryo development.

Morpho-molecular evaluation for developmental competence of oocytes retrieved through transvaginal ovum pick-up from FSH-stimulated Tharparkar donor cows (Bos indicus).

The study was conducted on indigenous Tharparkar cow (Bos indicus) to evaluate FSH stimulation on follicular attributes, oocyte recovery and morpho-molecular developmental competence parameters concerning oocyte quality. A total of 20 OPU sessions were performed, which included 10 sessions in each FSH stimulated at the dose of 130 µg divided into four sub-doses and non-stimulated. Findings on the size of follicles having ≥6 mm showed a significantly higher, however an opposite trend was observed in the case of smaller sized follicle (<6 mm) between stimulated and non-stimulated respectively. The stimulated cows had a significantly higher number as well as the percentage of oocytes of Grade A, having a diameter ≥120 µm and BCB+VE as compared to the non-stimulated cows. The relative mRNA expression profile of GDF9, BMP15, PCNA and BCL-2 genes was higher and BAX was lower in the FSH-stimulated cow. These results indicated that FSH stimulation before OPU in Bos indicus cows has a significant impact on follicle size, oocyte yield, recovery, and their quality with respect to COC's, diameter and BCB+VE oocytes. Further, a significant increase in the relative mRNA expression levels of GDF9, BMP15 and PCNA genes in the FSH-stimulated group suggests that FSH plays a key role in modulating the expression of these important candidate genes and thus influencing oocyte quality. The higher mRNA expression of BCL-2 genes and concomitantly lower expression of BAX gene in FSH Stimulated cows indicates the protective role of these genes and preventing programmed cell death and thus promoting cell survival, quality and embryo development.

Effects of hyperhomocysteinemia on follicular development and oocytes quality

Effects of hyperhomocysteinemia on follicular development and oocytes quality

A review of artificial intelligence applications in in vitro fertilization.

The field of reproductive medicine has witnessed rapid advancements in artificial intelligence (AI) methods, which have significantly enhanced the efficiency of diagnosing and treating reproductive disorders. The integration of AI algorithms into the in vitro fertilization (IVF) has the potential to represent the next frontier in advancing personalized reproductive medicine and enhancing fertility outcomes for patients. The potential of AI lies in its ability to bring about a new era characterized by standardization, automation, and an improved success rate in IVF. At present, the utilization of AI in clinical practice is still in its early stages and faces numerous ethical, regulatory, and technical challenges that require attention. In this review, we present an overview of the latest advancements in various applications of AI in IVF, including follicular monitoring, oocyte assessment, embryo selection, and pregnancy outcome prediction. The aim is to reveal the current state of AI applications in the field of IVF, their limitations, and prospects for future development. Further studies, which involve the development of comprehensive models encompassing multiple functions and the conduct of large-scale randomized controlled trials, could potentially indicate the future direction of AI advancements in the field of IVF.

Multi-omics approach to reveal follicular metabolic changes and their effects on oocyte competence in PCOS patients.

Polycystic ovary syndrome (PCOS) is a common heterogeneous disorder linked with endocrine and metabolic disturbances. The underlying mechanism of PCOS, especially its effect on oocyte competence, remains unclear. The study aimed to identify abnormal follicular metabolic changes using a multi-omics approach in follicular fluid from PCOS patients and to determine their effects on oocyte competence. A total of 36 women with PCOS and 35 women without PCOS who underwent in vitro fertilization and embryo transfer were included in the study. Cumulus cells and follicular fluid samples were collected. Follicular fluid samples underwent metabolomic analysis, while cumulus cell clusters from the same patients were assessed using transcriptomic analysis. Clinical information of patients and assisted reproductive technology (ART) results were recorded. Transcriptomics and metabolomics were integrated to identify disrupted pathways, and receiver operation characteristics (ROC) analysis was conducted to identify potential diagnostic biomarkers for PCOS. Pearson correlation analysis was conducted to assess the relationship between metabolites in follicular fluid and oocyte competence (fertilization and early embryo development potential). Through multi-omics analysis, we identified aberrantly expressed pathways at both transcriptional and metabolic levels, such as the citrate cycle (TCA cycle), oxidative phosphorylation, the cAMP signaling pathway, the mTOR signaling pathway, and steroid hormone biosynthesis. Ten candidate metabolites were identified based on metabolic profiling data from these altered pathways. Phytic acid, succinic acid, 2'-deoxyinosine triphosphate, and 4-trimethylammoniobutanoic acid in the follicular fluid exhibited high specificity and sensitivity in distinguishing PCOS. Among these metabolites, L-arginine showed a negative correlation with the 2PN fertilization rate and cleavage rate, while estrone sulfate showed a negative correlation with the high-quality embryo rate in the in-vitro fertilization (IVF) cycle. We have conducted a preliminary study of a novel metabolic signature in women with PCOS using a multi-omics approach. The alterations in key metabolic pathways may enhance our understanding of the pathogenesis of PCOS.

Expert opinion on refined and extended key performance indicators for individualized ovarian stimulation for assisted reproductive technology

ObjectiveTo assess the adequate ovarian follicular development and oocyte recovery between ovarian potential (antral follicle count [AFC]) before the start of ovarian stimulation (OS) and oocyte quantity and quality at oocyte retrieval. A holistic overview of the current key performance indicators (KPIs) was applied to identify the complementary strengths and identify where the current repertoire can be expanded. DesignExpert opinion. SubjectsNot applicable. InterventionNone. Main Outcome MeasuresTo formulate a proposal for a refined and expanded repertoire of KPIs for individualized OS for Assisted Reproductive Technology. ResultsThe performance and outcomes of OS on ovarian follicular development can be evaluated through the application of defined KPIs. Current KPIs for OS are the ovarian sensitivity index (OSI), the follicular output rate (FORT), the oocyte retrieval rate (ORR), and the follicle to oocyte index (FOI). Notably, there are no specific KPIs dedicated to the assessment of follicular development (i.e., recruitment, selection, growth and dominance). In light of this, we recommend expanding the current KPIs for OS to include “Early FORT” (accounting for the number of follicles measuring ≥10–11 mm on Day 5/6 of OS relative to AFC) and “Modified FORT” (the ratio between the number of follicles measuring ≥12 mm at the time of oocyte maturation triggering and AFC); the extension of ORR to include two discrete categories at oocyte retrieval: follicles ≥12 mm and follicles ≥16 mm, to ensure all responsive follicles are accounted for; and FOI to be measured at oocyte maturation triggering and oocyte retrieval ("Advanced FOI”). ConclusionsOnce validated and adopted in clinical practice, we envisage that the proposed expanded KPIs measuring the effect of OS on follicular development (recruitment, selection, growth and dominance) will increase the understanding of the relationship between ovarian reserve measured by AFC and oocyte quantity and quality at oocyte retrieval. This understanding will enable physicians to better evaluate the direct effect of different gonadotropins and doses on ovarian response, leading to a more personalized approach to OS in the context of ART treatment.

Oocyte Competence, Embryological Outcomes and miRNA Signature of Different Sized Follicles from Poor Responder Patients

Poor ovarian response (POR) patients often face the risk of not having enough competent oocytes. Then, aspirating small follicles could serve as a strategy to increase their number. Many efforts have been addressed to associate follicular size with oocyte competence, but results are controversial. Therefore, our study aimed to evaluate oocyte maturation and developmental competence, along with a non-invasive oocyte-maturation-related miRNA signature in oocytes retrieved from both large and small follicles. A total of 178 follicles, from 31 POR patients, were aspirated and measured on the day of ovarian puncture. Follicular diameters, oocyte collection, oocyte maturation, fertilization, blastocysts, and good-quality blastocyst rates were recorded. Simultaneously, follicular fluids were collected to quantify their miRNA expression. The efficacy of oocyte retrieval along with oocyte maturation, fertilization, and blastulation rates tended to increase with follicular size, but few significant differences were found. Despite there being significantly more collected oocytes from follicles &gt; 11.5 mm compared to follicles ≤ 11.5 mm (p &lt; 0.05), oocytes from the latter were also mature, with no significant differences in the miRNA signature, but only those &gt; 13.5 mm demonstrated developmental competence. In conclusion, 11.5 mm follicles can produce mature oocytes, but only those larger than 13.5 mm yielded transferable embryos.

The DNA double-strand break repair proteins γH2AX, RAD51, BRCA1, RPA70, KU80, and XRCC4 exhibit follicle-specific expression differences in the postnatal mouse ovaries from early to older ages.

Ovarian aging is closely related to a decrease in follicular reserve and oocyte quality. The precise molecular mechanisms underlying these reductions have yet to be fully elucidated. Herein, we examine spatiotemporal distribution of key proteins responsible for DNA double-strand break (DSB) repair in ovaries from early to older ages. Functional studies have shown that the γH2AX, RAD51, BRCA1, and RPA70 proteins play indispensable roles in HR-based repair pathway, while the KU80 and XRCC4 proteins are essential for successfully operating cNHEJ pathway. Female Balb/C mice were divided into five groups as follows: Prepuberty (3weeks old; n = 6), puberty (7weeks old; n = 7), postpuberty (18weeks old; n = 7), early aged (52weeks old; n = 7), and late aged (60weeks old; n = 7). The expression of DSB repair proteins, cellular senescence (β-GAL) and apoptosis (cCASP3) markers was evaluated in the ovaries using immunohistochemistry. β-GAL and cCASP3 levels progressively increased from prepuberty to aged groups (P < 0.05). Notably, γH2AX levels varied in preantral and antral follicles among the groups (P < 0.05). In aged groups, RAD51, BRCA1, KU80, and XRCC4 levels increased (P < 0.05), while RPA70 levels decreased (P < 0.05) compared to the other groups. The observed alterations were primarily attributed to altered expression in oocytes and granulosa cells of the follicles and other ovarian cells. As a result, the findings indicate that these DSB repair proteins may play a role in the repair processes and even other related cellular events in ovarian cells from early to older ages.

Porcine granulosa cell transcriptomic analyses reveal the differential regulation of lncRNAs and mRNAs in response to all-trans retinoic acid in vitro.

The active metabolite of vitamin A, all-trans retinoic acid (ATRA), is involved in the proliferation and differentiation of granulosa cells, and promotes the follicular development, oocyte maturation, and ovulation in mammals. This study aims to investigate the ATRA induced potential long noncoding RNAs (lncRNAs) that regulate the expression of genes associated with granulosa cell proliferation and follicular development. The lncRNA and mRNA profiles of porcine granulosa cells from ATRA treatment and control group in vitro were constructed through RNA sequencing. Meanwhile, the sequencing data were verified using quantitative polymerase chain reaction (qPCR). A total of 86 differentially expressed lncRNAs and 128 differentially expressed genes (DEGs) were detected in granulosa cells after ATRA treatment. The qRT-PCR results were consistent with the RNA-seq data. Functional annotation analysis revealed that the DEGs were remarkably enriched in ovary function and reproduction which contained FoxO, Hippo, Oocyte meiosis, mTOR signaling pathway, as well as several pathways associated with hormone regulation like Oxytocin signaling pathway and Steroid hormone biosynthesis. Moreover, an interaction network of lncRNAs and their cis-target DEGs was constructed, and 7 differentially expressed lncRNAs and 6 cis-target DEGs were enriched in ovarian steroidogenesis and reproduction. These findings expand the lncRNA catalogue and provide a basis for further studies on the mechanism of ATRA-mediated lncRNA regulation of follicular development in pigs.

Changes in surfactant protein A and D in ovine ovaries related to follicle development.

Surfactant protein A (SP-A) and Surfactant protein D (SP-D) glycoproteins play a crucial role in maintaining lung homeostasis and lung host defense. Interestingly, these proteins are also expressed in extra-pulmonary tissues, including the female genital tract. The ovarian tissue, where SP-A and SP-D expression increases with follicular development, may serve as the primary site of defense for this tissue. However, their functions in these tissues are not well understood and are currently an active area of research. Therefore, the objective of this study is to investigate the expression of SP-A and SP-D in the ovine ovary throughout the ovarian cycle using immunohistochemistry by semiquantitative intensity classification and Western blotting techniques. These findings revealed the presence of SP-A and SP-D in various compartments of the ovary, such as the follicular epithelium, granulosa cells, cumulus cells, theca cells, oocyte I, follicular fluid, and luteal cells of Graafian follicles, excluding the corpus albicans. SP-A and SP-D likely act as a first line of defense against potential pathogens that infiltrate the ovaries. Further investigation of the differential expression of SP-A and SP-D proteins in ovarian follicles will provide a basis for understanding their interactions with key proteins involved in oogenesis.

O-301 Progesterone Primed Ovarian Stimulation (PPOS) for DuoStim combined with PGT-A in poor prognosis patients: a valuable strategy

Abstract Study question Is PPOS rather than conventional GnRH-antagonist a valid strategy in DuoStim protocols? Summary answer PPOS-DuoStim and conventional-DuoStim showed similar mean euploid blastocyst rate (EBR) per inseminated metaphase-II (MII) oocytes. What is known already DuoStim (double stimulation in the same ovarian cycle) is an efficient strategy to increase the number of oocytes retrieved and embryos obtained in the shortest possible timeframe. PPOS is based on the use of exogenous oral progesterone to prevent LH surge during ovarian stimulation (OS). The effectiveness and safety of PPOS have been consistently reported across the last years, supporting it as a clinically-valuable OS protocol. To date, no evidence exists about PPOS application in DuoStim protocols and its association with oocyte competence, defined as EBR per MII-oocytes. Study design, size, duration Retrospective study involving 138 PPOS-DuoStim and 138 matched conventional-DuoStim patients treated at a single clinic between 2021 and 2022 and collecting ≥1 MII-oocyte after both stimulations. Matching was based on maternal age (40.3±2.7 years), number of oocytes collected after the I-stimulation (5.8±3.6 years), and sperm quality (66% normozoospermic). The primary outcome was the EBR per MII-oocytes. All intermediate embryological and clinical outcomes were also compared. Sub-analyses among I- and II-Stimulations were also conducted. Participants/materials, setting, methods DuoStim entailed the same protocol in I- and II-Stimulations with FSH 300IU/day+LH 150IU/day, 5 days spanning the two stimulations and GnRH-agonist to trigger ovulation. The only difference between PPOS-DuoStim and conventional-DuoStim was the administration of medrossiprogesterone acetate10mg/day orally from the first day of stimulation versus flexible GnRH-antagonist from the day the follicles reached a diameter of 13-14 mm. The same laboratory procedures were applied: ICSI, trophectoderm biopsy, comprehensive-chromosome-testing to report uniform aneuploidies and vitrified-warmed single-embryo-transfers. Main results and the role of chance The patients in the two groups were comparable for ovarian reserve markers, BMI, and duration of infertility. All data were comparable in conventional-DuoStim and PPOS-DuoStim (Mann-Whitney U tests were conducted): (i) overall fertilization rate per inseminated MII-oocytes were 73.1±23.2% versus 76.8±17.8% (p = 0.143), (ii) overall blastulation rate per 2PN-zygotes were 46.6±30.4% versus 45.7±25.1%(p = 0.797), (iii) overall euploidy rates per biopsied blastocysts were 24.1±30.9% versus 25.4±31.3%(p = 0.956), (iv) EBR per inseminated MII-oocytes were 9.6±17% versus 9.2±12.7% (p = 0.735). The data among only I- and II-stimulations were also similar. When comparing I- versus II-stimulations, paired t-tests highlighted longer II-stimulations (11±1.9 vs11.6±1.9 days, p = 0.001), resulting in larger cohorts of MII-oocytes (4.3±2.8 vs 5.2±3.3, p &amp;lt; 0.001) with comparable EBR per MII-oocytes (9.7±20.2% vs 11.6±16.2%, p = 0.233), thereby eliciting larger cohorts of euploid blastocysts (0.5±0.07 vs 0.7±0.09, p = 0.005). These data were confirmed also among conventional-DuoStim and PPOS-DuoStim study arms only. From a cycle perspective, among the 138 conventional-DuoStim couples, 31 (22%), 44 (32%) and 59 (43%) obtained ≥1 euploid blastocyst after I-stimulation, II-stimulation and overall, respectively. The same figures among the 138 PPOS-DuoStim were 36 (26%), 44 (32%) and 63 (46%), respectively. No statistical difference was reported (Fisher’s exact test=0.716). Limitations, reasons for caution Retrospective single center design. The current sample size should be doubled in order to reach a 80%-power with a 5%-α to exclude a 5% two-sided difference in the primary outcome. Patients’ compliance and discomfort, as well as clinical, gestational, and perinatal outcomes and cost-effectiveness analyses are needed. Wider implications of the findings PPOS is valuable in unconventional-OS protocols entailing freeze-all, like DuoStim with PGT-A. Future studies should assess if PPOS-DuoStim, by decreasing the number of injections and scans, may improve patient compliance and decrease OS discomfort. Any putative impact on follicular recruitment and oocyte yield should also be determined. Trial registration number not applicable

P-681 LH priming before ovarian stimulation in POSEIDON-4 patients: effects on oocyte recovery and post ICSI/IVF pregnancy rates

Abstract Study question Can a seven-day long LH priming treatment preceding ovarian stimulation (OS) improve follicular responses, oocyte yields and ICSI/IVF outcomes of POSEIDON-4 patients? Summary answer A seven-day long LH priming can substantially increase pregnancy rates through specific benefits in different subgroups of POSEIDON-4 patients. What is known already The combination of advanced maternal age (AMA) with diminished ovarian reserve (DOR) has become one of the most relevant and complex topics in the field of reproductive medicine. AMA/DOR patients appear to be refractory to increased gonadotropin dose and may benefit from strategies specifically capable of increasing the population of FSH-responsive small follicles before the onset of ovarian stimulation (OS). Androgen mediated LH intra-ovarian activity stimulates early follicular development. Pre-treatment with LH has been suggested to improve ICSI/IVF outcomes in normal responders but has not been assessed in AMA/DOR patients, despite the prevalence and relevance of this population. Study design, size, duration Retrospective cohort study from 2022 to 2023, including 235 POSEIDON-4 patients stimulated with FSH+LH in a flexible antagonist protocol with oestradiol pre-treatment (n = 129) or with the same stimulatory treatment preceded by a seven-day LH priming (150 IU/day) combined with GnRH agonist downregulation (n = 106). Follicular responses, oocyte recovery and ICSI/IVF outcomes were compared between treatment-groups in overall POSEIDON-4 patients and in a subgroup of patients with AMH &amp;lt;0.75 ng/mL (n = 77/Control, n = 59/LH priming). Participants/materials, setting, methods All participants were POSEIDON-4 caucasian patients aged 35 to 44 years undergoing a single homologous ICSI/IVF cycle in our clinic. Outcomes in the form of percentages were compared with the Fisher’s exact test, whereas differences in continuous variables were assessed with the Wilcoxon sum rank test. A multivariate analysis was performed to control for the interference of unequal variations in maternal age, AMH, insemination method and presence of male subfertility. Main results and the role of chance Patients in different treatment groups did not differ (p &amp;gt; 0.05) regarding maternal age (39.2±2.5 vs. 39.3±2.5), basal FSH serum concentrations (11.0±4.6 vs. 10.1±4.3) and antral follicle count (6.3±3.0 vs. 6.4±3.3, for patients stimulated with and without LH priming, respectively), but patients treated with LH priming presented slightly lower AMH serum levels (0.56±0.3 vs. 0.63±0.3; p = 0.05). Nevertheless, patients treated with LH priming achieved a twice higher clinical pregnancy rate per cycle (19.8% vs. 9.3%; p = 0.02), accompanied by a 40% reduction in cycle cancellation (32.1% vs. 45.0%; p = 0.03) and increased production of viable embryos (transferred fresh + frozen) per cycle (1.22±1.09 vs. 0.94±1.07; p = 0.02) and per oocyte inseminated (48.3% vs. 38.5%; p = 0.01), but did not differ regarding follicular outputs or oocyte yield. The multivariate analysis indicated a robust association between LH priming and pregnancy achievement, independently of potential confounding variables (OR = 2.52; p = 0.02). A two-fold increase in pregnancy achievement was also observed in severely restricted POSEIDON 4 patients (AMH &amp;lt;0.75 ng/mL) subjected to the LH priming (p = 0.05), which in this case was accompanied by higher oocyte yields per cycle (3.3±2.8 vs. 2.2±2.0; p = 0.04) and per pick (3.9±2.6 vs. 2.3±2.0; p &amp;lt; 0.01). Limitations, reasons for caution This study is limited by its retrospective nature and the data may be potentially influenced by the use of different downregulation strategies in the treatment-groups, even if the literature indicates equivalent performance for these strategies in the population under analysis. Wider implications of the findings The present data strongly suggest that a seven-day LH priming preceding OS can markedly improve ICSI/IVF outcomes of POSEIDON-4 patients, while indicating that this strategy benefits in different ways subgroups of this increasingly prevalent patient category. These findings thus represent new valuable parameters for the progress of ovarian stimulation. Trial registration number NA

P-661 Comparative and descriptive molecular analysis of cumulus and luteinized mural granulosa cells for steroidogenic function in IVF patients

Abstract Study question Do cumulus granulosa cells (CCs) have steroidogenic function and gonadotropin response like luteinized mural granulosa cells (LMGCs)? Summary answer Yes. Both types of granulosa cells have similar expression levels for the steroidogenic enzymes and hCG/LH receptors. What is known already CCs and LMGCs have distinct roles in follicular development, oocyte growth and maturation, cumulus expansion, ovulation, and luteinization. CCs support oocytes, especially during meiotic resumption, ovulation, and fertilization. They exhibit specialized functions in response to hormones like LH and participate in bidirectional communication with the oocyte. Although LMGCs are primarily responsible for steroidogenic function and progesterone (P4) production, very limited data is available as to whether CC themselves express the steroidogenic enzymes and gonadotropin receptors and produce sex steroids at basal or after gonadotropin stimulation in humans. We aimed to address this issue in the current study. Study design, size, duration An in-vitro basic science study was designed to compare CCs and LGMCs in the context of vitality, steroidogenic capabilities (both in baseline and response to rec-hCG (10 IU/ml), and EGF pathway responses. The assessment was planned to compare hormonal assay in spent culture and transcriptional levels. The study’s duration encompassed the period of ovarian stimulation, oocyte retrieval, and subsequent cellular analysis. Participants/materials, setting, methods 24 IVF patients undergoing ovarian stimulation with progestin primed (PPOS) and GnRH antagonist protocols for different infertility etiologies were included. Ovarian stimulation and ovulation trigger were done using rec-FSH and rec-hCG, respectively. CCs were collected from the denudation plate. LMGCs were obtained from follicular aspirates during the OPU and cultured individually for each patient without pooling in culture plates. After overnight incubation, the cells were treated with rec-hCG overnight. RNA isolation was performed. Main results and the role of chance The expression of the steroidogenic enzymes (StAR, SCC, 17B-HSD, 3B-HSD, Aromatase), LH receptor and EGF-like amphiregulin (AREG) in CCs were comparable to LMGCs on quantitative RT-PCR analysis. In line with this finding, we found they produced similar amounts of estradiol (E2) and progesterone (P4) in culture. Furthermore, similar to LMGCs, hCG treatment of the CCs resulted in a significant increase in P4 output, indicative of the presence of functional LH receptors. When the culture period was extended to six days, CCs retained their vitality and steroidogenic function like LMGCs and produced detectable E2 and P4. Limitations, reasons for caution Caution should be exercised when interpreting our data as it is unclear if the parameters analyzed here vary according to the infertility etiology, stimulation protocol, mode of trigger and any underlying disease that concomitantly present. Wider implications of the findings Prominent steroidogenic activity of CCs might have other important implications for a successful pregnancy. Moreover, similar expression profiles of steroidogenic pathways and hCG/LH receptors between CCs and LMGCs indicate that CCs can also be used to understand better the luteal function and intricate crosstalk between in oocyte microenvironment. Trial registration number N/A

O-043 Con

Abstract Dual and/or double trigger improve IVF success - CON The improvement of in vitro fertilization (IVF) outcomes remains a pivotal area of reproductive medicine research, with the dual trigger approach emerging as a significant innovation. This con abstract explores the scientific basis, methodology, and outcomes associated with the dual trigger strategy, juxtaposed with conventional triggering methods in IVF protocols. The dual trigger, incorporating both Gonadotropin-Releasing Hormone Agonist (GnRHa) and Human Chorionic Gonadotropin (hCG), has been posited to improve oocyte maturation, retrieval-, and live birth rates. By scrutinizing recent studies, clinical trials, and meta-analyses, this debate aims to delineate the efficacy, safety, and application scope of this approach. Initial investigations into the dual trigger method have highlighted its potential to ameliorate oocyte quality and maturity, which are crucial determinants of IVF success. The mechanism underlying this improvement involves the simultaneous activation of LH (Luteinizing Hormone) and FSH (Follicle Stimulating Hormone) receptors, enhancing follicular response and oocyte developmental competence. Studies have demonstrated an increase in the number of mature oocytes retrieved, attributed to the more synchronized and comprehensive follicular stimulation afforded by the dual trigger. This augmentation in oocyte quality and quantity directly correlates with enhanced embryo development profiles, and higher implantation and clinical pregnancy rates. Furthermore, the dual trigger method has shown promise in reducing the incidence of Ovarian Hyperstimulation Syndrome (OHSS), a severe complication of IVF treatments. By leveraging the luteolytic effects of GnRHa, this strategy minimizes the risk associated with exogenous hCG administration, thus offering a safer alternative for patients predisposed to OHSS. The application of the dual trigger in specific patient cohorts, such as those with PCOS or poor ovarian responders, has been underlined, indicating its potential for personalized reproductive medicine. However, the implementation of the dual trigger strategy is not without challenges. Variability in patient response necessitates a highly individualized approach, with precise dosing and timing adjustments to optimize outcomes. The existing literature presents a heterogeneity in study designs, populations, and outcome measures, which complicates the direct comparison of dual trigger efficacy against traditional methods. Furthermore, the long-term safety and potential impacts on offspring warrant further investigation, given the recent adoption of this approach. In conclusion, the dual trigger strategy may offer significant benefits in enhancing IVF outcomes. Its potential to improve oocyte maturity and quality could increase the number of retrievable oocytes and reduce the incidence of OHSS. However, it is important to acknowledge that, while the GnRH agonist trigger combined with a freeze-all strategy eliminates the risk of OHSS in women with PCOS, the dual trigger approach followed by fresh embryo transfer does not. Further research is imperative to refine its application, understand its mechanisms fully, and establish comprehensive guidelines for its use. The promise of the dual trigger approach underscores the importance of continuous innovation and evidence-based practices in enhancing the efficacy and safety of IVF treatments.

Follicular oocyte as a potential target for severe acute respiratory syndrome coronavirus 2 infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in December 2019 and rapidly became a pandemic as coronavirus disease 2019 (COVID-19). Apart from other organs, presence of specific receptor angiotensin-converting enzyme (ACE2) and corresponding proteases such as transmembrane serine protease 2, basigin and cysteine protease cathepsin L make follicular somatic cells as well as oocyte as potential targets for SARS-CoV-2 infection. The SARS-CoV-2 causes inflammation and hypoxia that generate reactive oxygen species (ROS) in critically ill patients. In addition, a large number of casualties and insecurity of life due to repeated waves of SARS-CoV-2 infection generate psychological stress and cortisol resulting in the further generation of ROS. The excess levels of ROS under physiological range cause meiotic instability, while high levels result in oxidative stress that trigger various death pathways and affect number as well as quality of follicular oocytes. Although, emerging evidence suggests that the SARS-CoV-2 utilises cellular machinery of ovarian follicular cells, generates ROS and impairs quality of follicular oocytes, the underlying mechanism of viral entry into host cell and its negative impact on the follicular oocyte remains poorly understood. Therefore, this review summarises emerging evidence on the presence of cellular machinery for SARS-CoV-2 in ovarian follicles and the potential negative impact of viral infection on the follicular oocytes that affect ovarian functions in critically ill and stressed women.

Influence of Long Non-Coding RNAs on Human Oocyte Development.

Recent research findings have highlighted the pivotal roles played by lncRNAs in both normal human development and disease pathogenesis. LncRNAs are expressed in oocytes and early embryos, and their expression levels change dynamically once the embryonic genome is activated during early human embryonic development. Abnormal expression of lncRNAs was found in follicular fluid, granulosa cells and oocytes of patients, and these lncRNAs were related to cell proliferation and apoptosis, nuclear maturation and follicle development. The expression levels of some lncRNAs in cumulus cells demonstrate correlations with the quality of oocytes and early embryos. This paper aims to present a comprehensive overview of the influence of LncRNAs on the developmental process of human oocytes as well as their involvement in certain infertility-related diseases.

The use of surfagon for the induction of ovulation of mares in ART cycles

In order to predict the timing of ovulation in mares, to obtain mature oocytes and follicular fluid in ART cycles, the domestic analogue of GnRH surfagon was used in two doses (40 and 50 mcg) against the background of comparison with the effectiveness of the previously used hCG drug. Surfagon injections were carried out intramuscularly when the leading follicle reached a diameter of 35 mm or more, and there was maximum or decreased edema of the uterus. An analysis of the duration of the intervals between intramuscular injection of 40 µg and 50 µg of the drug and ovulation showed that 72.4 and 35% of ovulations occur, respectively, between 37 and 48 hours after injection. The result of using 40 µg of surfagon is similar to the results of using hCG - 72 and 74% of ovulations in this period, respectively. Therefore, the drug “Surfagon” at a dose of 40 µg is most suitable for use in ART cycles. Only 3.4% of ovulations after the use of 40 µg of surfagon occur in the interval up to 24 hours after injection. Therefore, its use allows planning the collection of follicular fluid and oocyte from the preovulatory follicle using the OPU method after 24 hours. The domestic drug Surfagon (lyuleberin acetate, CJSC Mosagrogen, Moscow) is effective for the induction of ovulation in mares and can serve as an alternative to the use of HCG and imported GnRH analogues both in normal reproduction practice and in planning OPU procedures for the purpose of follicular fluid intake and oocyte extraction.

Generation of mouse and rat xenogeneic ovaries in vitro for production of mouse oocyte

ABSTRACT The system forming ovarian follicles is developed to investigate in vitro folliculogenesis in a confined environment to obtain functional oocytes. Several studies have reported the successful generation of fully functional oocytes using mouse-induced pluripotent stem cells (iPSCs) and mouse female germline stem cells (fGSCs) as sources of stem cells for in vitro gametogenesis models. In addition, human oogonia have been generated through heterologous co-culture of differentiated human primordial germ cell-like cells (hPGCLCs) with mouse germline somatic cells, although oocyte formation remains challenging. Thus, studies on in vitro ovarian formation in other species are utilized as an introductory approach for in vitro mammalian gametogenesis by understanding the differences in culture systems between species and underlying mechanisms. In this study, we optimized the method of the entire oogenesis process from rat embryonic gonads. We identified well-maturated MII oocytes from rat gonads using our constructed method. Moreover, we generated the first successful in vitro reconstitution of xenogeneic follicles from mouse primordial germ cells (PGCs) and rat somatic cells. We also established an appropriate culture medium and incubation period for xenogeneic follicles. This method will be helpful in studies of xenogeneic follicular development and oocyte generation.