Association between the proportion of dominant follicles and oocyte developmental competence

Increasing dominant follicular proportion was associated with adverse IVF/ICSI outcomes in low-prognosis women undergoing GnRH antagonist protocol: a retrospective cohort study

PURPOSE

This study aimed to examine the correlation between different dominant follicle proportions (DFPs) and outcomes of in-vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) among patients classified under POSEIDON Groups 3 and 4, who underwent gonadotropin-releasing hormone antagonist (GnRH-ant) protocols. Additionally, it sought to determine the optimal DFP threshold for trigger timing.

METHODS

A retrospective analysis was performed on patients classified under POSEIDON Groups 3 (n = 593) and 4 (n = 563) who underwent GnRH-ant protocols for controlled ovarian hyperstimulation (COH) between 2016 and 2022. These patients were categorized into two groups based on their DFPs, defined as the ratio of ≥ 18-mm dominant follicles to ≥ 12-mm follicles on the trigger day (DFP ≤ 40% and DFP ≥ 40%). Statistical analyses, including restricted cubic spline (RCS) and multivariate logistic regression, were employed to assess the relationship between DFP and IVF/ICSI outcomes.

RESULTS

Demographic characteristics of patients were similar across groups. In POSEIDON Groups 3 and 4, DFP > 40 was associated with a significant decrease in the number (No.) of oocytes retrieved, cleaved embryos, and available embryos. Moreover, following the GnRH-ant cycle, the clinical pregnancy and live birth rates in fresh embryo transfer (ET) were notably reduced in the DFP > 40 group compared with the DFP ≤ 40 group, whereas no significant differences were observed in the pregnancy outcomes of the first frozen-thawed embryo transfer (FET) between the groups. In POSEIDON Group 3, the cumulative clinical pregnancy rate (CCPR) and cumulative live birth rate (CLRB) were significantly higher in the DFP ≤ 40 subgroup than in the DFP > 40 subgroup, with a notable decrease in CLRB observed with increasing DFP levels. However, in POSEIDON Group 4, no significant differences in CCPR and CLRB were found between the groups. Logistic regression analysis identified age and the No. of oocytes retrieved as pivotal factors influencing CLRB in Group 4.

CONCLUSION

For patients in POSEIDON Group 3, maintaining a DFP ≤ 40 mm is crucial to achieve optimal laboratory and pregnancy outcomes by avoiding delayed triggering. However, for patients in POSEIDON Group 4, age remains a critical factor influencing CLRB regardless of DFP, although a higher No. of oocytes retrieved and available embryos with DFP ≤ 40 is beneficial.

Meta-analysis of trigger timing in normal responders undergoing GnRH antagonist ovarian hyperstimulation protocol

IMPORTANCE

The first meta-analysis focused only on gonadotropin-releasing hormone (GnRH) antagonists, which helped determine the effect of delay trigger on pregnancy outcomes.

OBJECTIVE

To evaluate the impact of delay trigger compared with standard trigger in normal responders undergoing GnRH antagonist protocol in improving pregnancy outcomes.

METHODS

Studies published before April 2023 in PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, VIP and CBM databases were searched. Randomized controlled trials (RCTs) and cohort studies conducted in normal responders reporting the efficacy of delay trigger using GnRH antagonist protocol were included. Data were combined to calculate mean differences (MD) for continuous variables and odd ratios (OR) for categorical variables with their corresponding 95% confidence intervals (CIs). Heterogeneity was assessed using Cochran's Q test.

RESULTS

Endpoints, including clinical pregnancy rate (CPR), live birth rate (LBR), the number of oocyte retrievals and embryos, and fertilization rate, were analyzed. Six (6) clinical studies (4 RCTs and 2 cohort studies) with 1,360 subjects were included. The pooled results showed that the number of oocyte retrievals (MD: 1.20, 95% CI: 1.10, 1.30, p < 0.01), fertilization rate (MD: 0.64, 95% CI: 0.29, 0.99, p < 0.01) and days of stimulation (MD: 0.95; 95% CI: 0.54, 1.37; p < 0.01) in the delay trigger group was significantly higher than that in the standard trigger group. However, there was no significant difference in the number of embryos (MD: 0.19, 95% CI: -0.29, 0.67, p = 0.44), CPR (OR: 1.12; 95% CI: 0.72, 1.75; p = 0.062), and LBR (OR: 1.23; 95% CI: 0.90, 1.66; p = 0.19) between the two trigger groups.

CONCLUSION

Delaying trigger time in GnRH antagonist protocol increased the number of oocytes retrieved but not the number of embryos. Furthermore, delay trigger shot was not associated with a clinical benefit towards CPR and LBR in women who underwent fresh embryo transfer cycles.

TRIAL REGISTRATION

The International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42023413217.

Letrozole cotreatment improves the follicular output rate in high-body-mass-index women with polycystic ovary syndrome undergoing IVF treatment

BACKGROUND

Women who have polycystic ovary syndrome (PCOS) with high body mass index (BMI) typically have an attenuated ovarian response and decreased follicular size, which are linked to unfavourable clinical outcomes following in vitro fertilization (IVF) therapy. The follicular output rate (FORT), a qualitative indicator of follicular response, seems to be positively linked to the clinical outcomes of IVF. Progestin-primed ovarian stimulation (PPOS) has become an alternative to gonadotropin-releasing hormone (GnRH) analogues to inhibit the premature luteinizing hormone (LH) surge. As letrozole (LE) shows promise in enhancing ovarian response, we compared PPOS with and without LE for PCOS in high BMI women with a focus on the FORT and associated clinical and pregnancy outcomes.

METHODS

For the recruited 1508 women, ten variables including AFC; age; basal sex hormone level; BMI; infertility type; period of infertility and number of previous IVF attempts were chosen in the propensity score matching (PSM) model to match 1374 women who taken the MPA+ hMG protocol with 134 women who received the MPA+ hMG+ LE treatment at a 1:1 ratio. FORT was selected as the primary outcome measure. The number of oocytes retrieved, viable embryos, hMG dosage, duration, oocyte maturity rate, fertilization rate, and implantation rate were established as secondary outcomes.

RESULTS

FORT was substantially elevated in the MPA+hMG+LE group compared with the MPA+hMG group (61% [35%, 86%] vs. 40% [25%, 60%], P <.001). Interestingly, the LE cotreatment group had a considerably lower mature oocyte rate despite having a similar number of mature oocytes and embryos recovered. The average hMG dosages and durations in the study group were similar to those in the control group. The implantation rate in the study group was numerically higher but without statistic significant than that in the control groups (43.15% (107/248) vs. 38.59% (115/298), OR 1.008, 95% CI 0.901-1.127; P >.05).

CONCLUSION

The effect of LE combined with PPOS on FORT is better than the effect of the standard PPOS treatment in women with PCOS and a high BMI, but there is no substantially beneficial impact on pregnancy outcomes or the cycle features of COS, including consumption of hMG.

Increasing dominant follicular proportion negatively associated with good clinical outcomes in normal ovarian responders using the depot GnRH agonist protocol: a large-sample retrospective analysis

BACKGROUND

Currently, there is no universal criteria for the trigger time of controlled ovarian hyperstimulation (COH), especially with the emerging depot GnRH agonist protocol. It is challenging to explore an indicator that is representative of target follicle cohort development as an alternative to the conventional approach of determining the trigger time based on a few leading follicles.

METHODS

This was a large-sample retrospective analysis. Between January 2016 and January 2020, 1,925 young normal ovarian responders who underwent their first in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycle using the depot GnRH agonist protocol were included. They were divided into three groups based on the dominant follicular proportion (DFP, defined as the ratio of ≥ 18 mm dominant follicles/ ≥ 14 mm large follicles on the human chorionic gonadotropin (HCG) day; Group A: < 30%; Group B: 30%-60%; and Group C: ≥ 60%). The binary logistic regression and multivariate linear regression were used to assess whether the DFP was associated with clinical pregnancy, the number of frozen blastocysts, the blastocyst formation rate, and the low number of frozen blastocysts.

RESULTS

The logistic regression analysis showed that compared with Group A, the odds ratio (OR) for clinical pregnancy was 1.345 in Group B (P = 0.023), and there was no statistical difference between Group C and Group A (P = 0.216). The multivariate linear regression analysis showed that DFP was negatively associated with the number of frozen blastocysts (β ± SE: Group B vs. Group A = - 0.319 ± 0.115, P = 0.006; Group C vs. Group A = - 0.432 ± 0.154, P = 0.005) as well as the blastocyst formation rate (β ± SE: Group B vs. Group A = - 0.035 ± 0.016, P = 0.031; Group C vs. Group A = - 0.039 ± 0.021, P = 0.067). Furthermore, the OR for the low number of frozen blastocysts was 1.312 in Group B (P = 0.039) and 1.417 in Group C (P = 0.041) compared to Group A.

CONCLUSIONS

For young normal ovarian responders using the depot GnRH agonist protocol, increasing DFP might reduce the developmental potential of oocytes and reduce the number of available blastocysts, and this might result in a lower cumulative pregnancy rate. However, further confirmation using strict prospective randomised controlled studies is required.

Is there a correlation between follicle size and gene expression in cumulus cells and is gene expression an indicator of embryo development?

BACKGROUND

In an article published in 2017, we discussed the results of the first part of our study into the morphokinetic development of embryos in relation to follicle diameter and homogeneity of follicular development. Our findings showed that embryos coming from small follicles in heterogeneous cycles had significantly higher rates of arrest or failure to reach blastocyst than embryos coming from large follicles in homogenous cycles. The aim of this further study was to investigate the relationship between follicular size and gene expression of cumulus cells (CCs) and evaluate whether gene expression could be an indicator of embryo development.

METHODS

This study was based on 2495 COCs from 184 patients. CC expressions of five genes (TNFAIP6, PTGS2, HAS2, PTX3 and GDF9) were studied by generalized linear mixed models (GLMMs) regarding follicular size. CC expressions were then separately analysed regarding patient-specific variables (age, BMI, AMH and follicular size) in relation to embryos reaching blastocyst (eRB) or top or good quality blastocysts (TQ + GQ) using GLMMs with logit link.

RESULTS

Follicular size significantly correlated with the potential of an oocyte to develop into a blastocyst: oocytes developing from large follicles were more than twice as likely to develop into an eRB than oocytes from small follicles (p < 0.001). Gene expression of HAS2 and GDF9 correlated with blastocyst quality when separately evaluated with follicular size and the patient specific variables of age, BMI and AMH. However, no such correlation was found in other gene expressions studied.

CONCLUSIONS

Our findings suggest that differences in the expression of genes studied could be related to follicular size rather than to embryo quality. Although gene expression of HAS2 and GDF9 correlated with blastocyst quality, the only variable correlating with eRB and TQ and GQ blastocysts for each of these five models was follicular size.

TRIAL REGISTRATION

This prospective cohort study was registered at clinicaltrials.gov (NCT02230449).