Oocyte Yield Research Articles

Anti-Müllerian hormone as a predictor of oocyte yield following controlled ovarian stimulation in the rhesus macaque

Abstract Anti-Müllerian hormone (AMH) is widely used in the clinic as a biomarker for ovarian reserve and to predict ovarian response to gonadotropin stimulation. Patients with higher AMH levels tend to yield more oocytes and have better outcomes from assisted reproductive technology (ART) procedures. The goal of this study is to determine if AMH can be used to predict the outcome of controlled ovarian stimulation in rhesus macaques, which are commonly used in biomedical research, to refine animal use while maximizing oocyte yield. We hypothesized that pre-stimulation AMH values can be used to predict oocyte yield and quality. Regularly cycling adult macaques underwent controlled ovarian stimulation and baseline (pre-stimulation) plasma AMH levels were determined using an AMH-specific enzyme-linked immunoassay. Oocytes were collected by laparoscopic or ultrasound-guided aspiration, then counted and evaluated for quality and stage of meiosis. Sperm from established fertile males were used to inseminate the oocytes in vitro with fertilization success checked 14 – 16 hours later. Females were grouped by oocyte yield: low ≤ 17; mid = 18 – 41; high ≥ 42. We found that high and mid yielders had significantly higher AMH than low yielders (p<0.0001) and the percent of mature oocytes was greater in the high and mid yielders. There were no significant differences in oocyte quality or ova fertilization rate. These data suggest that AMH is a useful measure for controlled ovarian stimulation success in rhesus macaques and can be used to identify suitable animals for oocyte donation before entering them into a stimulation protocol.

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.

Regulator of G-Protein Signaling 2 Knockout in CD4+ T Cells Promotes Anti-Inflammatory T Cells, Enhancing Ovulation, and Oocyte Yield.

To determine the downstream effects on ovarian function and immune cell differentiation in the ovary and uterus using a model in which RGS2 was knocked out specifically in CD4+ T cells. Laboratory based experiments with female mice. Female congenic (fully backcrossed) and non-congenic (mixed strain) mice with CD4 T cell-specific RGS2 knockout. Four-week-old female CD4 RGS2 knockout (CD4 RGS2 KO ) mice and their littermate controls (CD4 RGS2 CTL ) were subjected to superovulation using pregnant mare serum gonadotropins. Oocyte numbers, lymphocyte populations in the ovary and uterus, and serum estradiol and progesterone concentrations. In non-congenic (mixed strain) mice, CD4 RGS2 knockout (KO) promoted higher oocyte ovulation and increased uterine total leukocyte numbers. Similarly, congenic (fully backcrossed strain) mice showed higher oocyte numbers and increased uterine total leukocytes in the CD4 RGS2 KO mice compared to CD4 RGS2 CTL mice. Pro-inflammatory CD4+ T helper (T H ) 1 and T H 17 cell frequencies in the ovary and uterus were unchanged, while Treg and T H 2 cell frequencies were elevated, along with increased concentrations of estradiol and progesterone in the serum of CD4 RGS2 KO mice. Our study highlights the important role of RGS2 in CD4+ T cells within the context of reproduction. The dysregulation of immune responses due to RGS2 knockout in CD4+ T cells appears to enhance oocyte production. Further research is warranted to elucidate the precise mechanisms by which RGS2 influences reproductive outcomes, including its impact on fecundability, endometrial receptivity, and successful implantation.

EFFECT OF FSH PRE-STIMULATION ON OOCYTE RECOVERY IN ONGOLE (&lt;i&gt;Bos indicus&lt;/i&gt;) COWS

The present study was aimed to assess the efficacy of oocyte retrieval through transvaginal ovum pick-up (OPU) in Ongole (Bos indicus) cows. Cows (n=18) were divided in to two equal groups; cows in group 1 cows were subjected to two OPU sessions (OPU1 and OPU2) at 96 h interval irrespective of the stage of estrus cycle. Cows of group 2 were subjected to FSH pre-stimulation before OPU 1 followed by OPU 2, 96h later. Thus, a total of 36 OPU sessions were performed on 18 animals. The number of follicles available for aspiration (17.89 ± 1.78 vs 27.06 ± 1.75), number of medium (4 – &lt; 8 mm; 4.11 ± 0.69 vs 16.00 ± 1.76) and large follicles (≥ 8mm; 1.06 ± 0.23 vs 6.33 ± 0.79), follicles aspirated (11.95 ± 1.42 vs 17.45 ± 2.07), COCs recovered (5.72 ± 0.78 vs 10.06 ± 1.78), and viable COCs collected (4.23 ± 0.67vs 8.34 ± 1.79) were significantly higher in group 2 than in group 1.The mean number of follicles aspirated, the mean oocyte recovery and the viable oocytes collected were significantly higher at OPU 1 in both the groups than at OPU 2. It was concluded that pre-treatment with FSH increased the OPU efficiency in terms of oocyte yield and viable oocytes collected. OPU 2 performed at shorter interval after OPU 1 is not advantageous due to limited number of follicles available for aspiration at OPU 2 and consequently, reduced oocyte recovery.

Impact of GnRH antagonist pretreatment on oocyte yield after ovarian stimulation: A retrospective analysis.

The study investigates whether a 3-day pretreatment course with a GnRH antagonist in the early follicular phase has an impact on the number of retrieved COCs in a GnRH antagonist stimulation protocol. This is a retrospective single center crossover study involving women who did not conceive after one GnRH antagonist stimulation cycle ("standard cycle") and proceeded with another GnRH antagonist stimulation cycle preceded by early administration of GnRH antagonist for 3 days ("pretreatment cycle") with fresh embryo transfer or frozen embryo transfer. 430 patients undergoing 860 cycles were included. The mean female age was 34.4 ± 4.8 years. Indications for fertility treatment included unexplained infertility (34.3%), male-factor infertility (33.3%), age (16.9%), PCOS (8.2%), tubal (4.7) and endometriosis (2.6%). All cycles were divided into two groups: group 1 (standard, 430 cycles) and group 2 (pretreatment, 430 cycles). The mean duration of stimulation was similar in both groups (10.3 vs 10.3 days, p = 0.28). The starting dose of gonadotropin (234.9 vs 196.8 IU, p<0.001), total amount of gonadotropin used (2419 vs 2020 IU, p<0.001), the total number of retrieved COCs (10 vs 7.8 p<0.001) and the number of mature oocytes (8 vs 5.8 p<0.001) were significantly higher in group 2 than in group 1. The Generalized estimating equation (GEE) regression analysis showed that the pretreatment strategy had a significant positive effect on the number of COCs (coefficient 2.4, p <0.001 after adjusting for known confounders (age, indication, stimulation dose, type, and duration of stimulation). In conclusion, A 3-day course of GnRH antagonist pretreatment increases the number of COCs obtained after ovarian stimulation.

Transrectal oocyte retrieval for fertility preservation in virginal women

Research QuestionFertility preservation faces barriers due to sociocultural and religious factors in some countries for nulliparous women who are virgins. Transrectal oocyte retrieval is an alternative technique which can address this by circumventing sensitivities around pelvic procedures in such women who require to have oocyte cryopreservation for medical or social reasons. The study aims to evaluate safety and efficacy of Transrectal oocyte retrieval (TROR) procedure for fertility preservation in these women. DesignA retrospective single centre study of 105 nulliparous women from five satellites of Fakih IVF in the United Arab Emirates, who underwent TROR for oocyte cryopreservation. Extensive bowel preparation and rectal cleansing was performed prior to oocyte retrieval. Outcome and safety data were collected on patient characteristics, stimulation protocols, oocyte yield in relation to age, AMH, number of follicles, and BMI. ResultsThis study evaluated 105 patients who underwent 152 cycles of ovarian stimulation and TROR. The most common indication was social fertility preservation. Correlation with patient characteristics included age, and AMH were performed. AMH showed a statically significant positive correlation with number of oocytes (p≤0.003). No intraoperative or postoperative complications were observed. ConclusionOur study demonstrated that TROR is Our study demonstrated that TROR is an alternative and clinically-effective oocyte harvesting procedure in ART, producing good results in terms of oocyte yield, with no complications and good safety profile. Although Transvaginal oocyte retrieval remains the gold standard treatment, for virginal women where transvaginal oocyte retrieval is not an option, TROR is safe and effective.

Exposure of antral follicles to medroxyprogesterone acetate during stimulation does not cause molecular perturbations in gonadotropin-responsiveness and steroidogenic function of granulosa cells in progestin-primed cycles.

Does medroxyprogesterone acetate (MPA) exposure in progestin-primed ovarian stimulation (PPOS) cycles cause molecular perturbations in the steroidogenic function and gonadotropin responsiveness of the granulosa cells? PPOS cycles are identical to traditional GnRH antagonist cycles not only for clinical IVF characteristics but also for gonadotropin receptor expression, response to gonadotropins, and steroidogenic function at the molecular level. PPOS is increasingly used as an alternative to GnRH antagonists due to the inhibitory effect of progesterone on LH release by reducing GnRH pulsatility at the hypothalamic level. Although a growing body of evidence from clinical studies did not indicate significant differences between PPOS and antagonist protocols for IVF cycle characteristics and obstetrical outcomes, it is still unknown whether exposure of the antral follicle cohort to progesterone or its synthetic derivatives during ovarian stimulation causes any subtle molecular aberrations in terms of steroidogenesis and gonadotropin responsiveness. To address this issue, detailed comparative molecular analyses were conducted in the luteinized mural granulosa cells (GCs) obtained from normal responding IVF patients undergoing PPOS and antagonist cycles. A clinical translational research study was conducted with IVF patients. This study included 55 normal responding IVF patients who underwent ovarian stimulation with either PPOS using MPA (5 mg twice daily) or GnRH antagonist cetrorelix acetate. Recombinant forms of FSH and hCG were used for ovarian stimulation and ovulation triggering, respectively. Luteinized mural GCs obtained during the oocyte retrieval procedure were used for the experiments. Cell culture, quantitative real-time PCR, immunoblotting, confocal time-lapse live cell imaging, and hormone assays were used. Demographic and IVF cycle characteristics of the patients undergoing ovarian stimulation with PPOS and GnRH antagonist were similar, including ovarian response, mature oocyte yield, and fertilization rates. Molecular analyses revealed that the expression of the enzymes involved in sex-steroid synthesis (StAR, SCC, 3β-HSD, 17β-HSD, aromatase) and the uptake/storage/utilization of cholesterol (LDL receptor, Hormone-sensitive lipase, hydroxy-methyl glutaryl Co-enzyme-A reductase, and Sterol O-acyltransferase1) in the GCs of the PPOS cycles were comparable to those of the antagonist cycles. The expression of the receptors for gonadotropins, estrogen, and progesterone hormones was also similar. Basal and hCG-induced increases in 3β-HSD expression and progesterone production and basal and FSH-induced increases in aromatase expression and E2 output of the GCs from PPOS patients did not exhibit any meaningful differences when compared with GCs from antagonist cycles. Furthermore, basal and hCG-induced up-regulation in the LDL receptor expression and cholesterol uptake did not differ between the groups. Confocal imaging also revealed similar patterns of expression for the steroidogenic enzymes and their co-localization with mitochondria. Lastly, the expression of the other important genes regulating cumulus expansion, ovulation, and luteal function [Relaxin, ADAMTS-1, and epidermal growth factor (EGF)-like growth factor amphiregulin] in the GCs of the PPOS and antagonist cycles were similar. N/A. Caution should be exercised when interpreting our data which was derived from normally responding patients whose ovulation was triggered with hCG. It is unclear whether the molecular parameters assessed vary according to infertility etiologies, magnitude of ovarian response, mode of trigger, and any other underlying ovarian pathologies or systemic diseases. MPA was the progestin used for PPOS and whether these findings can be generalized to other progestins is unknown. This study provides reassuring molecular evidence that exposure of antral follicle cohorts to MPA during the follicular growth phase does not have any detrimental effects on steroidogenic, ovulatory, and luteal functions when compared with GnRH antagonist cycles. This study was funded by the School of Medicine, the Graduate School of Health Sciences of Koc University and Koç University Research Center for Translational Medicine (KUTTAM), and equally funded by the Republic of Turkey Ministry of Development Research Infrastructure Support Program. All authors declare no conflict of interest. N/A.

Utilization of Assisted Reproductive Technologies in Breeding Auliekol Cattle: A Comparative Study.

This study evaluates the utilization of in vitro embryo production (IVEP) technology for the conservation and breeding of the Auliekol cattle breed, a primary beef breed in Kazakhstan facing population decline due to the cessation of breeding programs and the incursion of transboundary diseases. We assessed the effect of consecutive ovum pick-up (OPU) procedures on oocyte yield and embryo production in Auliekol and Aberdeen Angus cows. A total of 2232 and 3659 oocytes were aspirated from Auliekol and Aberdeen Angus donors, respectively, with significantly higher yields and embryo production observed in Aberdeen Angus cows. The application of a meiotic block using Butyrolactone I (BLI) and subsequent in vitro fertilization (IVF) protocols was employed, with embryo development monitored up to the morula/blastocyst stage. Results indicated that Auliekol cows exhibited lower oocyte recovery, cleavage, and blastocyst rates compared to Aberdeen Angus cows, likely due to genetic characteristics. Despite the challenges, IVEP presents a valuable tool for the preservation and future propagation of the Auliekol breed, highlighting the need for further research to enhance reproductive outcomes and conservation strategies.

Luteinizing hormone supplementation with human menopausal gonadotropin versus low dose human chorionic gonadotropin during ovarian stimulation does not affect live birth rates after fresh and frozen embryo transfer.

Luteinizing hormone (LH) plays an important role in ovarian follicle maturation. Human menopausal gonadotropin (hMG) or low dose human chorionic gonadotropin (hCG) can provide LH supplementation during in vitro fertilization (IVF) ovarian stimulation, though studies directly comparing their impact on IVF outcomes are limited. The aim of the study was to determine whether LH supplementation with hMG versus low dose hCG during IVF stimulation affects live birth rate. Fresh and frozen embryo transfers (ET) from 2017 to 2021 after standard long or antagonist protocols supplemented with hMG (75-250 IU) or low dose hCG (50-100 IU) during stimulation cycles in our academic center were included. Statistical analysis was performed with T-tests, Mann-Whitney U tests, Chi-square, and multiple linear and logistic regression. Four hundred and sixty eight unique stimulation cycles resulting in 213 fresh and 412 frozen embryo transfers were analyzed. There was a lower mature oocyte yield (10.9 vs. 11.8, p = 0.044) but similar high-quality blastocyst yield (3.6 vs. 3.9, p = 0.11) for hMG vs low dose hCG. Live birth rates per transfer were comparable for fresh (42% vs. 49%, p = 0.24) and frozen (46% vs. 53%, p = 0.45) embryo transfers. Multiple logistic regressions showed no association between supplemental gonadotropin and live birth for both fresh and frozen embryo transfers. Fresh and frozen IVF-ET pregnancy outcomes were comparable after hMG versus low dose hCG supplementation, suggesting flexibility in supplemental LH dosing regimens that may address patient or physician preference or cost concerns.

Oocyte yield and live birth rate after follitropin delta dosing and fresh embryo transfer: an individual patient data meta-analysis

Research questionWhat number of retrieved oocytes is associated with the optimum chance to achieve a live birth for women undergoing ovarian stimulation with individualised follitropin delta? DesignIndividual patient data meta-analysis of 1772 patients from five randomised controlled trials using individualised follitropin delta for ovarian stimulation with fixed daily dosing based on serum anti-Müllerian hormone (AMH) and body weight. Outcomes of live birth rate (LBR) and ovarian hyperstimulation syndrome (OHSS) were evaluated in relation to the number of oocytes retrieved, including subgroup analyses based on number of oocytes retrieved, age and AMH levels. ResultsThe analysis included patients treated with follitropin delta who had ≥1 oocyte retrieved. The mean number of oocytes retrieved was 10.4 and the overall LBR was 32.1%. Predicted LBR increased with the number of oocytes retrieved, reaching above 34% in the range 8-14 oocytes, peaking at 34.9% for 11 oocytes. Beyond 14 oocytes, LBR gradually declined. By number of oocytes retrieved (grouped), the LBR was 27.8%, 33.6% and 30.9% at 1-7, 8-14 and ≥15 oocytes, respectively. LBR decreased with increasing age (32.7%, 30.7% and 23.4% at <35, 35-37 and 38-42 years, respectively). The incidence of OHSS (any grade) increased from 2.1% to 5.2% to 17.0% at 1-7, 8-14 and ≥15 oocytes retrieved. ConclusionsAfter ovarian stimulation with individualised follitropin delta, the LBR in the fresh cycle was highest in the range of 8-14 oocytes retrieved, peaking at 11 oocytes. The results support the appropriateness of the follitropin delta dosing algorithm.

Fertility protection during chemotherapy treatment by boosting the NAD(P)+ metabolome.

Chemotherapy induced ovarian failure and infertility is an important concern in female cancer patients of reproductive age or younger, and non-invasive, pharmacological approaches to maintain ovarian function are urgently needed. Given the role of reduced nicotinamide adenine dinucleotide phosphate (NADPH) as an essential cofactor for drug detoxification, we sought to test whether boosting the NAD(P)+ metabolome could protect ovarian function. We show that pharmacological or transgenic strategies to replenish the NAD+ metabolome ameliorates chemotherapy induced female infertility in mice, as measured by oocyte yield, follicle health, and functional breeding trials. Importantly, treatment of a triple-negative breast cancer mouse model with the NAD+ precursor nicotinamide mononucleotide (NMN) reduced tumour growth and did not impair the efficacy of chemotherapy drugs in vivo or in diverse cancer cell lines. Overall, these findings raise the possibility that NAD+ precursors could be a non-invasive strategy for maintaining ovarian function in cancer patients, with potential benefits in cancer therapy.

Optimizing oocyte yield utilizing a machine learning model for dose and trigger decisions, a multi-center, prospective study

The objective of this study was to evaluate clinical outcomes for patients undergoing IVF treatment where an artificial intelligence (AI) platform was utilized by clinicians to help determine the optimal starting dose of FSH and timing of trigger injection. This was a prospective clinical trial with historical control arm. Four physicians from two assisted reproductive technology treatment centers in the United States participated in the study. The treatment arm included patients undergoing autologous IVF cycles between December 2022–April 2023 where the physician use AI to help select starting dose of follicle stimulating hormone (FSH) and trigger injection timing (N = 291). The control arm included historical patients treated where the same doctor did not use AI between September 2021 and September 2022. The main outcome measures were total FSH used and average number of mature metaphase II (MII) oocytes. There was a non-significant trend towards improved patient outcomes and a reduction in FSH with physician use of AI. Overall, the average number of MIIs in the treatment vs. control arm was 12.20 vs 11.24 (improvement = 0.96, p = 0.16). The average number of oocytes retrieved in the treatment vs. control arm was 16.01 vs 14.54 (improvement = 1.47, p = 0.08). The average total FSH in the treatment arm was 3671.95 IUs and the average in the control arm was 3846.29 IUs (difference = −174.35 IUs, p = 0.13). These results suggests that AI can safely assist in refining the starting dose of FSH while narrowing down the timing of the trigger injection during ovarian stimulation, benefiting the patient in optimizing the count of MII oocytes retrieved.

Use of tamoxifene-controlled ovarian hyperstimulation for fertility preservation before breast cancer treatment: A prospective cohort study with a 5-year follow-up

PurposeFertility issues are of great concern for young women undergoing treatment for breast cancer (BC). Fertility preservation (FP) protocols using controlled ovarian stimulation (COS) with letrozole have been widely used with overall good results. However, letrozole cannot be used in every country in this context. This study aimed to assess the efficacy of tamoxifen for COS in women with early BC undergoing FP. MethodsThis multicentric prospective study included patients aged 18–40, diagnosed with stage I, II and III invasive BC, undergoing tamoxifen-COS before adjuvant or neoadjuvant chemotherapy (NAC). The primary endpoint was the efficacy of tamoxifen-COS protocol evaluated by the number of oocytes collected and vitrified. Secondary endpoints included the time interval before chemotherapy, breast cancer (BC) recurrence rates, and reproductive outcomes. ResultsNinety-five patients were included between 2014 and 2017, aged 31.5 ± 4 years on average. 37.9 % received NAC and 62.1 % received adjuvant chemotherapy. FP procedure was successful in 89.5 % of the cycles. The mean number of collected and vitrified oocytes was 12.8 ± 7.9 and 9.8 ± 6.2, respectively. The mean duration of COS was 10.4 ± 1.9 days. Median time before chemotherapy initiation was 3.6 weeks (IQR 3.1; 4.1) for women receiving NAC. Five-year relapse-free and overall survival rates were in-line with those expected in this population. Twenty-one women had spontaneous full-term pregnancies, while 5 underwent IVF cycles with frozen-thawed oocytes, without pregnancy. ConclusionTamoxifen-COS protocols appear to be feasible before adjuvant or NAC treatment in young BC patients and efficient in terms of oocyte yield.

Spironolactone use and oocyte maturation in patients undergoing controlled ovarian hyperstimulation.

To evaluate the association between spironolactone use and controlled ovarian hyperstimulation (COH) outcomes. Retrospective study, including patients who underwent COH. Oocyte yield and maturation rates were compared by categories of spironolactone use at the start of their cycle. 402 patients were included. 83 patients continued spironolactone, 44 patients discontinued spironolactone, and 275 matched control patients were spironolactone-naïve. No difference was observed in the number of oocytes retrieved (17 ± 14 vs. 15 ± 13, p = 0.4) or mature oocytes vitrified (15 ± 9.5 vs. 12 ± 11, p = 0.4) in patients who continued spironolactone use and spironolactone naïve patients, respectively. When comparing patients who continued spironolactone use and patients who discontinued spironolactone use, no difference was seen in the number of oocytes retrieved (17 ± 14 vs. 17.5 ± 7.8, p = 0.9) or mature oocytes vitrified (15 ± 9.5 vs. 13.5 ± 6.5, p = 0.5), respectively. There was no observed relationship between total daily spironolactone dose (< 100mg/day, 100mg/day, 150mg/day and > 200 mg/day) and the total number of mature oocytes vitrified (respectively, 14.0 ± 13.0, 16.0 ± 7.8, 14.0 ± 4.5, 11.0 ± 7.0 oocytes, p = 0.4). This is the first study to evaluate the association between spironolactone and oocyte yield and maturation rates during COH cycles. These findings can assist in counseling patients on the implications of continuing spironolactone during COH cycle.

Transcriptomic profiling of the oocyte-cumulus-granulosa cell complex from estrogen receptor β knockout mice

To study the role of estrogen receptor beta in follicle development and maturation and in the response to gonadotropin stimulation aiming at superovulation DESIGN: Experimental study and transcriptomic analysis. Healthy wild-type and estrogen receptor beta (ERβ) knockout female mice undergoing superovulation at 4-weeks, 7-weeks, and 6-months of age. Oocyte yield after superovulation, transcriptomic profiling of cumulus-granulosa cell complexes and oocytes, and immunohistochemical analyses. Superovulation of ERβ knockout (Esr2-KO) mice resulted in reduced oocyte yield at 6-months of age compared to wild-type (WT) mice, but younger mice had similar yields. RNA-seq analysis of cumulus cells from superovulated WT and Esr2-KO mice identified genes and pathways associated with among others adhesion, proliferation, Wnt-signaling, and placed ERβ in bipotential granulosa cell cluster. Loss of ERβ increased expression of the other estrogen receptors Esr1 and Gper1. Our results show that ERβ has an important role in regulating ovulation in response to exogenous gonadotropins in 6-month-old mice, but not in younger mice. Our transcriptomic and immunohistochemical observations suggest a dysregulation of the granulosa cell communication and lack of tight coordination between granulosa cell replication and antrum expansion. A significant upregulation of other estrogen receptors may support a compensatory mechanism sustaining fertility during younger age in Esr2-KO mice.

Do women with severely diminished ovarian reserve undergoing modified natural-cycle in-vitro fertilization benefit from earlier trigger at smaller follicle size?

To evaluate whether trigger and oocyte collection at a smaller follicle size decreases the risk of premature ovulation while maintaining the reproductive potential of oocytes in women with a severely diminished ovarian reserve undergoing modified natural-cycle in-vitro fertilization. This was a retrospective cohort study including women who had at least one unsuccessful cycle (due to no response) of conventional ovarian stimulation with a high dosage of gonadotropins and subsequently underwent a modified natural cycle with a solitary growing follicle (i.e. only one follicle > 10 mm at the time of trigger). The association between follicle size at trigger and various cycle outcomes was tested using regression analyses. A total of 160 ovarian stimulation cycles from 110 patients were included in the analysis. Oocyte pick-up (OPU) was performed in 153 cycles and 7 cycles were canceled due to premature ovulation. Patients who received their trigger at smaller follicle sizes (≤ 15 mm) had significantly lower rates of premature ovulation and thus higher rates of OPU (98.9% vs 90.8%; odds ratio, 9.56 (95% CI, 1.58-182.9); P = 0.039) compared with those who received their trigger at larger follicle sizes (> 15 mm). On multivariable analysis, smaller follicle sizes at trigger (> 10 to 13 mm, > 13 to 15 mm, > 15 mm to 17 mm) were not associated significantly with a lower rate of cumulus-oocyte complex (COC) retrieval, metaphase-II (MII) oocytes or blastulation when compared to the > 17-mm group. On sensitivity analysis including only the first cycle of each couple, the maturity rate among those with COC retrieval was highest in follicle sizes > 15 to 17 mm (92.3%) and > 13 to 15 mm (91.7%), followed by > 10 to 13 mm (85.7%) and lowest in the > 17-mm group (58.8%). During the study period, five euploid blastocysts developed from 48 fertilized MII oocytes with follicle sizes of 12 mm (n = 3), 14 mm (n = 1) and 16 mm (n = 1) at trigger. Of those, four were transferred and resulted in two live births, both of which developed from follicles with a size at trigger of 12 mm. The ideal follicle size for triggering oocyte maturation may be smaller in women with a severely diminished ovarian reserve managed on a modified natural cycle when compared to conventional cut-offs. The risk of OPU cancellation was significantly higher in women triggered at follicle size > 15 mm and the yield of mature oocytes was not adversely affected in women triggered at follicle size > 13 to 15 mm compared with > 15 to 17 mm. Waiting for follicles to reach sizes > 17mm may be detrimental to achieving optimal outcome. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Exposure of women undergoing in-vitro fertilization to per-and polyfluoroalkyl substances: Evidence on negative effects on fertilization and high-quality embryos

In April 2023, the World Health Organization (WHO) reported that 17.5% of the global adult population experience infertility. What may be the contribution of per-and polyfluoroalkyl (PFAS) to this global public health problem?This study explored the associations between in vitro fertilization (IVF) outcomes and plasma concentrations of individual PFAS and PFAS mixtures in women undergoing in vitro fertilization and embryo transfer (IVF-ET) and how these exposures might affect IVF outcomes. We analyzed 8 PFASs in plasma samples from women (N = 259) who underwent IVF treatment. In multivariable generalized linear mixed models, there were statistically significant associations of higher plasma concentrations of PFNA with reduced numbers of total retrieved oocytes [12.486 (95%CI: 0.446,25.418), p trend = 0.017], 2 PN zygotes [6.467(95%CI: 2.034,14.968), p trend = 0.007], and cleavage embryos [6.039(95%CI: 2.162,14.240), p trend = 0.008]. Similarly, there was a continuous decline in the numbers of retrieved 2 PN zygotes and cleavage embryos with increasing concentration of PFOS [6.467(95%CI: 2.034,14.968), p trend = 0.009 and 6.039(95%CI: 2.162,14.240), p trend = 0.031,respectively] and a negative association between PFHxS concentrations and clinical pregnancy during the initial cycles of frozen ET [0.525(95%CI:0.410,0.640), p trend = 0.021]. To investigate the joint effect of PFAS mixtures, a confounder-adjusted BKMR model analysis showed inverse relationship between PFAS mixtures and the number of high-quality embryos, 2 PN zygotes and cleavage embryos, to which the greatest contributors to the mixture effect are PFDeA and PFBS, respectively. It demonstrated that PFAS exposure might exert negative effects on oocyte yield, fertilization and high-quality embryo in women undergoing IVF. These findings suggest that exposure to PFAS may increase the risk of female infertility and further studies are needed to uncover the potential mechanisms underlying the reproductive effects associated with PFAS.

P-669 Not the oocyte yield but the number of embryos predicts live birth at high response: analysis of 39,136 fresh IVF/ ICSI cycles from National Database

Abstract Study question Oocyte or embryo yield- which is a better predictor of live birth (LB) in fresh cycle IVF/ ICSI? Summary answer The embryo yield is better than oocyte in predicting fresh-cycle LB and positively correlates with LB at high ovarian response when the oocytes yield doesn’t. What is known already As the LB rates plateau after a certain oocyte yield, the number of oocytes collected no longer can predict the live birth in IVF/ ICSI cycles with fresh embryo transfer.Since pregnancy outcomes also depend on the number of mature oocytes obtained, fertilisation rate and subsequent embryo development, it can be postulated that the number of total or transferrable embryos could be a better predictor of LB. Study design, size, duration Retrospective analysis of 39,136 fresh IVF/ ICSI cycles that met the inclusion criteria from the national database published by Human Fertilisation and Embryology Authority (HFEA) in the United Kingdom. We analysed 2 years of published data between January 2015 and December 2016. Participants/materials, setting, methods Only the first cycles of IVF/ ISCI that had oocyte retrieval procedure with intended fresh embryo transfer were included. Couples with any cause of infertility and female partners aged up to 44 years were included. Very few cycles with &amp;gt;25 oocytes had fresh transfer, therefore excluded. The ovarian response has been graded by 0-5, 6-10, 11-15, 16-20, 21-25 collected oocytes. Significant confounders found in univariate analysis were adjusted for in the multiple regression model. Main results and the role of chance Women’s age, method of insemination (IVF or ICSI) and number of transferred embryos and stage of transfer significantly associated with LB in univariate analysis (p &amp;lt; 0.0001 each). The oocyte yield predicted fresh-cycle LB only in low response group (0-5 oocytes), but not in higher response groups. Total number of embryos, the number of transferable embryos and embryo utilisation rate remained positively correlated with LB in all response groups. The number of transferable embryos found to be the best predictor of LB with the highest adjusted OR 1.51 (CI:1.4-1.65, p &amp;lt; 0.0001) in the lowest response (0-5 oocyte) group, that gradually declined to 1.06 (CI:1.03-1.10, p = 0.0003) in 21-25 oocytes group. Followed next by the total number of embryos with the highest adjusted OR of 1.20 (CI:1.13-1.27, p &amp;lt; 0.0001) in the lowest response (0-5 oocytes) group, down to 1.04 (CI:1.02-1.06, p = 0.0003) in the 21-25 oocytes group. The number of oocytes was the weakest in predicting LB (adjusted OR 1.07 (CI 1.02-1.12; p = 0.003) in the 0-5 oocytes group only. The inference remained the same when ICSI cycles with supposedly sperm factor was excluded. Limitations, reasons for caution Information on patient’s BMI or stimulation dose is not available in the HFEA database. However, it might have little impact in our findings, given large sample size. Ages are given in groups, so the groups taken as ordinal (dummy) variables in multiple regression analysis. Cumulative LB data were not available. Wider implications of the findings Having been influenced by both oocyte and sperm competency, the number of transferable embryos may have a stronger relation with the pregnancy outcomes than merely the oocyte number. On theory, this may be applicable for cumulative LB too, but awaiting confirmation by data evidence. Trial registration number Not applicable

P-371 It’s worth the freeze: outcomes from thawing electively cryopreserved oocytes are comparable in patients with reduced vs normal ovarian reserve at the time of cryopreservation

Abstract Study question For patients coming back to use oocytes derived from elective cryopreservation, does their initial ovarian reserve predict thaw survival, embryos’ developmental milestones and pregnancy success? Summary answer Thaw survival, fertilization rate, embryo development and pregnancy success rates do not vary significantly according to AMH level at initial cryopreservation. What is known already Increasing numbers of patients are electing to cryopreserve oocytes for future use. AMH (Anti Mullerian Hormone) is an ovarian reserve marker often assessed prior to initiation of treatment that predicts response to fertility treatment and the resulting oocyte yield. However, it is not known whether oocytes derived from a patient with compromised ovarian reserve (perhaps over multiple treatment cycles) will fare as well as that of a patient with normal ovarian reserve and a higher per cycle oocyte yield. Our study seeks to shed light on whether a lower initial AMH level negatively impacts the prognosis of the thawed oocytes. Study design, size, duration We included in our retrospective study all oocyte thaw cycles resulting from electively cryopreserved oocytes since 1996 at a single academically affiliated fertility center. 325 patients completed a total of 510 thaw cycles. 315 cycles were excluded from analysis for no AMH information. 6376 oocyte cryopreservation cycles were performed over that timeframe. The primary outcomes were laboratory statistics including oocyte survival, fertilization and embryo blastulation rates, while the secondary outcome was cumulative live birth rates. Participants/materials, setting, methods AMH categories of &amp;lt; 1, 1-2 and &amp;gt; 2 were selected to stratify reduced, low-normal, and normal ovarian reserves, respectively. 70.7% inseminated oocytes with partner sperm while the remaining 29.3% used donor sperm. Mean age at time of oocyte cryopreservation was 36.5 (range 27.5 to 46.2) while mean age at time of oocyte thaw was 39.2 (range 27.7 to 47.5). The statistical analysis was performed using ANOVA for mean comparisons and chi-squared for pregnancy data. Main results and the role of chance Average oocyte yield per cryopreservation cycle was significantly different across AMH groups (7.7 oocytes in AMH &amp;lt; 1, 10.5 oocytes in AMH 1-2, and 17.2 oocytes in AMH &amp;gt; 2, p &amp;lt; 0.01). The number of treatment cycles completed was highest in patients with AMH &amp;lt; 1 at 1.26 cycles. Oocyte survival (mean 89.0%), fertilization rate (mean 75.3%), and blastocyst conversion rate (mean 62.4%) did not vary significantly across AMH groups. Time to oocyte use was not significantly impacted by AMH at the time of initial testing. Those with reduced AMH &amp;lt; 1 came back earlier to utilize the oocytes (787 days), vs 1141 days for patients with AMH 1-2 and 1021 days for patients with AMH &amp;gt; 2. However, this difference was not statistically significant, p = 0.4. The rate of PGT-A euploid embryos did not vary between groups (38.8% in AMH &amp;lt; 1, 45.3% in AMH 1-2, 53.0% in AMH &amp;gt; 2, p = 0.07). Clinical pregnancy, miscarriage rate, and live birth rate in the first transfer cycle was not impacted by AMH. Total cumulative live birth rate was not correlated with AMH (31.6% in AMH &amp;lt; 1, 44.4% in AMH 1-2, 47.8% in AMH &amp;gt; 2, p = 0.48). Limitations, reasons for caution This data was collected at a single fertility center and thus has limited generalizability. 8.0% of patients came back to utilize their oocytes, which varies widely across the published literature. 60.6% of patients did not have AMH assessed as part of their pre-treatment testing and were excluded from analysis. Wider implications of the findings Although reduced ovarian reserve impacts oocyte yield, many studies find no impact on resulting oocyte quality, embryo development and pregnancy success rates. Those with compromised AMH have comparable oocyte thaw outcomes to those with normal ovarian reserve, though more oocyte cryopreservation cycles may be needed to achieve a successful outcome. Trial registration number N/A

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