Reduced ovarian response to controlled ovarian stimulation is associated with increased oxidative stress in the follicular environment

Oxidative Homeostasis in Follicular Fluid and Embryo Quality-A Pilot Study

The objective of this study was to measure the different redox biomarker levels within the follicular fluid (FF) and evaluate correlations with embryo quality using the one follicle-one oocyte/embryo approach. The prospective study included 54 women (average age 34.6 ± 3.0 years). Out of the 235 mature metaphase II cells that underwent intracytoplasmic sperm injection, fertilization was achieved in 177 cells, producing 92 Grade I embryos, 26 Grade II embryos, 39 Grade III embryos, and 20 Grade IV embryos. The activities of antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and glutathione transferase were significantly higher in the group consisting of lower-quality (Grades II-IV) embryos in comparison with top-quality (Grade I) embryos (p = 0.011; p = 0.021; p = 0.008, respectively). The concentration of oxidative stress markers, malondialdehyde, 8-hydroxy-2'-deoxyguanosine, and thiol groups was significantly increased in the group with lower-quality embryos (Grades II-IV) compared to top-quality embryos (0.027; 0.018; 0.021, respectively). Furthermore, a significant positive correlation between each oxidative marker and the activities of antioxidant enzymes was observed (p < 0.001). According to our findings, the best embryos and, consequently, better in vitro fertilization outcomes are linked to low levels of oxidative stress and low antioxidant enzyme activity.

Effect of astaxanthin supplementation on female fertility and reproductive outcomes: a systematic review and meta-analysis of clinical and animal studies

CONTEXT

Oxidative stress (OS) plays a harmful role in female reproduction and fertility. Several studies explored various dietary interventions and antioxidant supplements, such as astaxanthin (AST), to mitigate the adverse effects of OS on female fertility. Ameliorative effects of AST on female fertility and the redox status of reproductive organs have been shown in several animal and clinical studies.

OBJECTIVES

The main objective of present systematic review and meta-analysis of both animal and clinical studies was to provide a comprehensive overview of the current evidence on the effects of AST on female fertility and reproductive outcomes. The effect of AST on redox status, inflammatory and apoptotic markers in reproductive organs were included as the secondary outcomes.

DATA SOURCES

We systematically searched electronic databases including PubMed, Scopus, and Web of Science, until January 1, 2024, using specified search terms related to AST, female reproductive performance, and infertility, considering the diverse synonyms found in the literature for interventional studies that compared oral AST supplementation with placebo or control in human or animal models.

DATA EXTRACTION

Two independent reviewers extracted data on study characteristics, outcomes, and risk of bias. We pooled the results using random-effects models and assessed the heterogeneity and quality of evidence. We descriptively reported the data from animal models, as meta-analysis was not possible.

DATA ANALYSIS

The meta-analysis of clinical trials showed that AST significantly increased the oocyte maturation rate (MD: 8.40, 95% CI: 4.57 to 12.23, I2: 0%) and the total antioxidant capacity levels in the follicular fluid (MD: 0.04, 95% CI: 0.02 to 0.06, I2: 0%). The other ART and pregnancy outcomes and redox status markers did not show statistically significant changes. The animal studies reported ameliorative effects of AST on redox status, inflammation, apoptosis, and ovarian tissue histomorphology.

CONCLUSION

This systematic review shows that AST supplementation may improve assisted reproductive technology outcomes by enhancing oocyte quality and reducing OS in the reproductive organs. However, the evidence is limited by the heterogeneity, risk of bias, and small sample size of the included studies.

Can follicular fluid 8-oxo-2'-deoxyguanosine predict the clinical outcomes in ICSI cycle among couples with normospermia male?

OBJECTIVE

Oxidative stress (OS) occurs when excess free radicals damage the DNA. Moreover, 8-oxo-2'-deoxyguanosine (8-OHdG) is a well-known biomarker for OS linked to cellular damage and gene instability. However, its role in female subfertility has not been properly assessed. We aimed to examine the level of OS represented by 8-OHdG based on the cause of subfertility and to test its correlation with reproductive hormones, intracytoplasmic sperm injection (ICSI) parameters, and outcomes.

METHODS

A cross-sectional study examined 108 subfertile couples with endometriosis, polycystic ovary syndrome (PCOS), tubal factors, and unexplained infertility undergoing ICSI treatment with two different stimulation programs. We included couples whose partners had normal sperm parameters. Levels of follicular fluid (FF) 8-OHdG were correlated with the causes of subfertility and fertilization rates and compared between pregnant and non-pregnant cases.

RESULTS

Based on the causes of subfertility, FF 8-OHdG was the highest among endometriosis cases, followed by PCOS cases. Furthermore, FF 8-OHdG was higher in non-pregnant (2.37±0.75 ng/mL) vs. pregnant (1.58±0.39 ng/mL), P<0.001. A two-way analysis of variance showed that only subfertility affected ICSI outcomes, whereas the stimulation program did not. FF 8-OHdG correlated positively with female age and inversely with estradiol and good-quality embryos. The receiver operating characteristic estimated 8-OHdG cutoff value of 1.8 ng/mL predicted clinical pregnancies with 86.7% sensitivity and 74.4% specificity (P<0.001).

CONCLUSION

Higher FF 8-OHdG levels negatively impacted ICSI outcomes. FF 8-OHdG discriminated between cases of clinical pregnancy with good specificity and sensitivity. Because OS can be measured and treated, this opens up a therapeutic and prognostic avenue for improving ICSI outcomes.

Ovarian stimulation protocols for poor ovarian responders: a network meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy of manifold ovarian stimulation protocols for patients with poor ovarian response.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were systematically searched until February 14, 2021. Primary outcomes included clinical pregnancy rate per initiating cycle and low risk of cycle cancellation. Secondary outcomes included number of oocytes retrieved, number of metaphase II (MII) oocytes, number of embryos obtained, number of transferred embryos, endometrial thickness on triggering day and estradiol (E2) level on triggering day. The network plot, league table, rank probabilities and forest plot of each outcome measure were drawn. Therapeutic effects were displayed as risk ratios (RRs) or mean differences (MDs) with 95% confidence intervals (CIs).

RESULTS

This network meta-analysis included 15 trials on 2173 participants with poor ovarian response. Delayed start GnRH antagonist was the best regimen in terms of clinical pregnancy rate per initiating cycle (74.04% probability of being the optimal), low risk of cycle cancellation (75.30%), number of oocytes retrieved (68.67%), number of metaphase II (MII) oocytes (97.98%) and endometrial thickness on triggering day (81.97%), while for E2 level on triggering day, microdose GnRH agonist (99.25%) was the most preferred. Regarding number of embryos obtained and number of transferred embryos, no statistical significances were found between different ovarian stimulation protocols.

CONCLUSION

Delayed start GnRH antagonist and microdose GnRH agonist were the two superior regimens in the treatment of poor ovarian response, providing favorable clinical outcomes. Future investigation is needed to confirm and enrich our findings.

The effect of growth hormone on the metabolome of follicular fluid in patients with diminished ovarian reserve

BACKGROUND

Increasing evidence supports that the co-treatment with growth hormone (GH) enhances ovarian response and oocyte quality during controlled ovarian stimulation (COS) in patients with diminished ovarian reserve (DOR). The composition of follicular fluid (FF) plays an essential role in oocyte development and mirrors the communication occurring between the oocyte and follicular microenvironment. However, the effect of GH on the FF metabolome remains unclear.

METHODS

This prospective observational study recruited DOR patients undergoing in vitro fertilization (IVF) cycles with minimal stimulation protocol for COS. Each patient receiving GH co-treatment was matched to a patient without GH co-treatment by propensity score matching. The FF was collected after isolating oocytes and assayed by gas chromatograph-mass spectrometry (GC-MS) metabolomics. The Pearson correlation was performed to evaluate the relationship between the number of oocytes retrieved and the levels of differential metabolites. The KEGG database was used to map differential metabolites onto various metabolic pathways.

RESULTS

One hundred thirty-four FF metabolites were identified by GC-MS metabolomics. Twenty-four metabolites, including glutathione, itaconic acid and S-adenosylmethionin (SAM) showed significant differences between the GH and control groups (p-value < 0.05 and q-value < 0.1). In addition, the number of oocytes retrieved was significantly higher in the GH group compared to the control group (3 vs 2, p = 0.04) and correlated with the levels of five differential metabolites. Among them, the levels of antioxidant metabolite itaconic acid were upregulated by GH administration, while SAM levels were downregulated.

CONCLUSIONS

The co-treatment with GH during COS may improve oocyte development by altering FF metabolite profiles in DOR patients. However, given the downregulation of SAM, a regulator of genomic imprinting, the potential risk of imprinting disturbances should not be neglected.

The average gonadotrophin dosage per follicle is predictive of ovarian response and cumulative live birth chances after in vitro fertilization: a retrospective cohort study

BACKGROUND

With the development of assisted reproduction technology (ART), many indicators have been proposed to evaluate ovarian response, and then predict pregnancy outcomes. In general, the predictive values remain limited.

OBJECTIVE

To further explore the indicators to evaluate ovarian sensitivity to gonadotrophin (Gn) stimulation more accurately.

METHODS

This retrospective cohort study included 330 women who underwent an entire ART cycle. We aimed to assess whether a new index, termed as average Gn dosage per follicle, could be used as a marker for ovarian response and pregnancy outcomes. It was calculated as the ratio of total Gn dose during ovarian stimulation and the number of pre-ovulatory follicles (PFC) on the trigger day. Patients were divided into three subgroups according to the average Gn dosage per follicle: below the 33rd percentile (Group A), between 33rd and 67th percentiles (Group B), and above the 67th percentile (Group C). Then stimulation data, laboratory and clinical outcomes were compared among the groups.

RESULTS

The results showed patients in Group A had the best ovarian response, the number of retrieved oocytes was significantly higher than in Group B and C. A multivariate regression analysis showed that average Gn dosage per follicle was an independent predictor of cumulative live birth rates (CLBRs) [adjusted odds ratio (OR): 0.96, 95% confidence interval (CI): 0.95-0.98, P < 0.01].

CONCLUSIONS

The present study showed that average Gn dosage per follicle appears to be a highly reliable index of ovarian response to exogenous Gn and can be useful to estimate CLBR.

Glucose consumption and gene expression in granulosa cells collected before and after in vitro oocyte maturation in the southern white rhinoceros (Ceratotherium simum simum)

CONTEXT

With two northern white rhinos (NWR) remaining, the continued existence of this species relies on studying their relative, the southern white rhino (SWR).

AIMS

(1) Characterise gene expression in granulosa cells (GC) from SWR cumulus oocyte complexes (COCs) prior to (Pre-) and after (Post-) in vitro maturation (IVM), comparing culture media and oocytes from donors treated with or without gonadotropin stimulation prior to ovum recovery; and (2) evaluate COC glucose consumption in spent media.

METHODS

COCs were retrieved from four SWRs. Granulosa cells were collected before and after IVM in SDZ or IZW medium. Total RNA was evaluated by qPCR.

KEY RESULTS

Oocyte maturation was greater in SDZ than IZW media. Expression of genes associated with follicle development increased in Pre-IVM GC. Six genes were differentially expressed in Post-IVM GC from stimulated compared to unstimulated donors. COCs from stimulated animals consumed more glucose. Fifty seven percent of oocytes in SDZ medium consumed all available glucose.

CONCLUSIONS

Gene expression changed upon in vitro maturation and gonadotropin stimulation. Higher glucose availability might be needed during IVM.

IMPLICATIONS

This is the first study examining GC gene expression and COC metabolic requirements in rhinoceros, which are critical aspects to optimise IVM of rhinoceros oocytes.

The Impact of Controlled Ovarian Stimulation on Serum Oxidative Stress Markers in Infertile Women with Endometriosis Undergoing ICSI

Endometriosis-related infertility is associated with oxidative stress (OS). The present study aims to compare serum OS markers of infertile women with endometriosis and controls during the follicular phase of the natural cycle (D1), after pituitary downregulation using a GnRH agonist (D2), after controlled ovarian stimulation (COS) on the day of human chorionic gonadotropin administration (D3), and on the day of oocyte retrieval (D4). One hundred and eight serum samples (58 controls and 35 early and 18 advanced endometriosis cases) were collected at these four timepoints. OS markers were compared among the groups and timepoints using a linear regression model with mixed effects and a post-test using orthogonal contrasts. The significance was set at 5%. We observed altered OS markers in the endometriosis patients during the D1, D2, D3, and D4 timepoints compared to the controls. The evidence of systemic OS in infertile patients with endometriosis during COS suggests the mobilization of potent antioxidants in an attempt to protect the oocyte from oxidative damage, especially on the day of oocyte retrieval.

Oxidative stress and DNA damage status in couples undergoing in vitro fertilization treatment

This study examined the status of oxidative stress in 599 couples undertaking in vitro fertilization (IVF) treatment and its association with reproductive hormones, smoking, and outcomes. Oxidative stress biomarkers such as malondialdehyde, 8-hydroxy-2-deoxyguanosine, hydrogen peroxide (H₂O₂), catalase (CAT), and total antioxidant capacity (TAC) were determined in follicular fluid and seminal plasma. Tail moment (TM) was used to evaluate DNA damage in the sperm and granulosa cells. Reproductive hormones in serum and cotinine (COT) in urine, follicular fluid, and seminal plasma samples were determined. Separate multivariate linear regression was used to assess associations between levels of each oxidative stress biomarker and each hormone and smoking parameter (modeled as natural log-transformed). The findings indicate that some oxidative stress and DNA damage biomarkers played a role in disrupting certain reproductive hormones in women and their male partners either by overproducing reactive oxygen species or reducing antioxidant defense capacity. Although women were nonsmokers, COT levels > 50 and 10 µg/L in urine and follicular were observed in 5.7 and 1.7%, respectively. Levels of follicular fluid COT were positively associated with H₂O₂ and TM. We used log-binomial multivariate regression to estimate relative risks for the association between oxidative stress/DNA damage and IVF binary outcomes (fertilization rate > 50%, biochemical pregnancy, clinical pregnancy, and live birth). An increase in the CAT levels of follicular fluid was associated with a 48 and 41% decrease in the risk of poor fertilization rate (≤50%) and unsuccessful live birth, respectively. After the models were adjusted for hormonal factors, the associations remained the same, except that the elevated TAC in follicular fluid became significantly associated with a decrease of 42% in the risk of poor fertilization rate (≤50%). The higher antioxidant activity (CAT and TAC) in follicular fluid might positively impact specific IVF outcomes.