Cycle day, estrogen level, and lead follicle size: analysis of 27,790 in vitro fertilization cycles to determine optimal start criteria for gonadotropin-releasing hormone antagonist

Estradiol Decline Before hCG Administration in COH Has a Negative Effect on IVF Outcomes in Patients Without OC Pretreatment

Purpose

Together with ultrasound measurement of follicle size, serum estradiol (E2) provides guidance for controlled ovarian hyperstimulation (COH). However, during the COH process, some patients experience decreased serum E2 level, especially before human chorionic gonadotropin (hCG) trigger. In order to elucidate the effect of E2 reduction as well as the role of oral contraceptive pretreatment, a retrospective study was performed in our center from 2013 to 2019.

Patients and Methods

In total, 333 patients who experienced an E2 decrease prior to hCG administration were recruited as E2 decline group, while 333 patients with continuously E2 increase during COH were considered as control group. Based on pretreatment strategy, the two groups were further categorized into oral contraceptive (OC) and non-OC sub-groups, and IVF and clinical outcomes were compared between paired groups.

Results

Number of dominant follicles on hCG day and normally fertilized zygotes were significantly decreased in E2 decline group, and the significantly reduced live birth rate in E2 decline group indicated the close relationship between E2 decline and clinical outcomes. To analyse further, we found that in patients without OC pretreatment, the pregnancy rate and live birth rate of E2 decline group (n = 141) were significantly lower than control group (n = 136) (56.3% versus 68.0%, 50.8% versus 63.5%, respectively). However, for patients with OC pretreatment, no difference was detected between two groups, suggesting a potential effect of OC pretreatment on clinical outcomes.

Conclusion

E2 decline prior to hCG-triggering day adversely affects IVF and clinical outcomes in patients without OC pretreatment, especially fertilization rate and live birth rate.

Association between serum LH levels on hCG trigger day and live birth rate after fresh embryo transfer with GnRH antagonist regimen in different populations

Objective

To investigate whether serum LH levels on hCG trigger day are associated with live birth rate (LBR) after fresh embryo transfer with GnRH antagonist regimen in different populations.

Methods

This study was a retrospective study. A total of 3059 fresh embryo transfers were divided into three populations: predicted normal ovarian responders (NOR) (n=2049), patients with PCOS (n=533), and predicted poor ovarian responders (POR) (n=477). Each population was stratified into three groups based on LH levels: < 25th percentile, 25-75th percentile, and > 75th percentile. The primary outcome of the study was LBR, and secondary outcomes included implantation, clinical pregnancy, and early pregnancy loss rates. Univariable and multivariable regression analyses were performed to adjust for potential confounders.

Results

In NOR, compared to the reference group (>75th percentile), LBR was significantly lower in the < 25th percentile group (adjusted OR=0.662; 95%CI, 0.508-0.863) and 25-75th percentile group (adjusted OR=0.791; 95%CI, 0.633-0.988). In PCOS patients, LBR decreased significantly in the < 25th percentile group (41.4%) compared to the 25-75th percentile group (53.7%) and > 75th percentile group (56.1%). In addition, the LBR was lower in the < 25th percentile group (33.6%) compared with the 25-75th percentile group (43.4%) and the>75th percentile group (42.0%) in POR, but this was not statistically significant.

Conclusions

High serum LH levels are associated with increased LBR after fresh embryo transfer in GnRH antagonist cycles, which may be attributable to higher implantation rate. LH may be a predictor of whether to schedule fresh embryo transfer in IVF cycles for better clinical outcomes.

What is the optimal GnRH antagonist protocol for ovarian stimulation during ART treatment? A systematic review and network meta-analysis

BACKGROUND

Several GnRH antagonist protocols are currently used during COS in the context of ART treatments; however, questions remain regarding whether these protocols are comparable in terms of efficacy and safety.

OBJECTIVE AND RATIONALE

A systematic review followed by a pairwise and network meta-analyses were performed. The systematic review and pairwise meta-analysis of direct comparative data according to the PRISMA guidelines evaluated the effectiveness of different GnRH antagonist protocols (fixed Day 5/6 versus flexible, ganirelix versus cetrorelix, with or without hormonal pretreatment) on the probability of live birth and ongoing pregnancy after COS during ART treatment. A frequentist network meta-analysis combining direct and indirect comparisons (using the long GnRH agonist protocol as the comparator) was also performed to enhance the precision of the estimates.

SEARCH METHODS

The systematic literature search was performed using Embase (Ovid), MEDLINE (Ovid), Cochrane Central Register of Trials (CENTRAL), SCOPUS and Web of Science (WOS), from inception until 23 November 2021. The search terms comprised three different MeSH terms that should be present in the identified studies: GnRH antagonist; assisted reproduction treatment; randomized controlled trial (RCT). Only studies published in English were included.

OUTCOMES

The search strategy resulted in 6738 individual publications, of which 102 were included in the systematic review (corresponding to 75 unique studies) and 73 were included in the meta-analysis. Most studies were of low quality. One study compared a flexible protocol with a fixed Day 5 protocol and the remaining RCTs with a fixed Day 6 protocol. There was a lack of data regarding live birth when comparing the flexible and fixed GnRH antagonist protocols or cetrorelix and ganirelix. No significant difference in live birth rate was observed between the different pretreatment regimens versus no pretreatment or between the different pretreatment protocols. A flexible GnRH antagonist protocol resulted in a significantly lower OPR compared with a fixed Day 5/6 protocol (relative risk (RR) 0.76, 95% CI 0.62 to 0.94, I2 = 0%; 6 RCTs; n = 907 participants; low certainty evidence). There were insufficient data for a comparison of cetrorelix and ganirelix for OPR. OCP pretreatment was associated with a lower OPR compared with no pretreatment intervention (RR 0.79, 95% CI 0.69 to 0.92; I2 = 0%; 5 RCTs, n = 1318 participants; low certainty evidence). Furthermore, in the network meta-analysis, a fixed protocol with OCP resulted in a significantly lower OPR than a fixed protocol with no pretreatment (RR 0.84, 95% CI 0.71 to 0.99; moderate quality evidence). The surface under the cumulative ranking (SUCRA) scores suggested that the fixed protocol with no pretreatment is the antagonist protocol most likely (84%) to result in the highest OPR. There was insufficient evidence of a difference between fixed/flexible or OCP pretreatment/no pretreatment interventions regarding other outcomes, such as ovarian hyperstimulation syndrome and miscarriage rates.

WIDER IMPLICATIONS

Available evidence, mostly of low quality and certainty, suggests that different antagonist protocols should not be considered as equivalent for clinical decision-making. More trials are required to assess the comparative effectiveness of ganirelix versus cetrorelix, the effect of different pretreatment interventions (e.g. progestins or oestradiol) or the effect of different criteria for initiation of the antagonist in the flexible protocol. Furthermore, more studies are required examining the optimal GnRH antagonist protocol in women with high or low response to ovarian stimulation.

Optimizing estradiol level for gonadotrophin-releasing hormone antagonist initiation among patients with simple tubal factor infertility

OBJECTIVE

The aim of this study is to investigate the optimal estradiol (E₂) level on the day of gonadotropin-releasing hormone antagonist (GnRH-ant) initiation to maximize the clinical pregnancy rate (CPR) after fresh embryo transfer among patients with simple tubal factor infertility.

METHODS

A retrospective cohort study was conducted in the Reproductive Medicine Center, the Second Hospital of Hebei Medical University. A total of 1,493 IVF-ET cycles of patients diagnosed with single tubal factor infertility from August 2016 to August 2021 were included and equally allocated into five distinct groups according to the quintile serum E₂ levels on the day of GnRH-ant initiation. The five groups had similar baseline data except for antral follicle count.

RESULTS

The serum E ₂ level on GnRH-ant initiation day was determined as an independent predictor of clinical pregnancy after adjusting for confounding factors such as age, infertility duration, body mass index, cycle number, antral follicle count, and the number of transferred embryos. Through smooth curve fitting, we found that, with the increase of serum E₂ levels on the day of GnRH-ant initiation, CPR showed a trend of slight increase and then slight decrease. The maximal CPR was achieved when the serum E₂ level on GnRH-ant initiation day was 498 pg/ml. When E₂ was less than 498 pg/ml, the odds ratio (OR) of clinical pregnancy was 1.05 (95% CI: 1.00, 1.11, P = 0.0583). When E₂ was greater than 498 pg/ml, the OR of clinical pregnancy was 0.97 (95% CI: 0.95, 0.98, P = 0.0003). Furthermore, CPR remained high when E₂ was 436.8-658.6 pg/ml but declined significantly by more than 40% when E₂ was ≥ 894.4 pg/ml (P < 0.05).

CONCLUSIONS

The serum E₂ level should be considered as an adjuvant parameter for GnRH-ant initiation. The best E₂ value was 498 pg/ml, and GnRH-ant administration could be recommended to initiate when serum E₂ was 436.8-658.6 pg/ml. If GnRH-ant was initiated when serum E₂ was above 894.4 pg/ml, then the CPR after fresh embryo transfer may decline dramatically, and thus, cancellation of fresh embryo transfer and earlier initiation of GnRH-ant in future cycles should be considered.

Comparison of ovarian response to follitropin delta in Japanese and White IVF/ICSI patients

RESEARCH QUESTION

Is ovarian response associated with individualized follitropin delta dosing regimen comparable across different ethnic populations?

DESIGN

Post-hoc analysis of ovarian response in 800 IVF/intracytoplasmic sperm injection (ICSI) patients (170 Japanese women and 630 White women) undergoing stimulation with individualized follitropin delta dosing based on serum anti-Müllerian hormone concentration and body weight in two randomized controlled trials conducted in Japan (NCT03228680) and in Europe, North America and South America (NCT01956110).

RESULTS

On average, Japanese women weighed 10 kg less, which affected the total follitropin delta dose, compared with White women (83.5 ± 28.9 versus 90.2 ± 25.2 µg). At the end of stimulation, serum FSH concentrations were not significantly different between Japanese and White women (median 14.3 versus 14.0 IU/l), whereas serum oestradiol concentrations were significantly higher in Japanese women (median 6517 versus 5298 pmol/l, P < 0.0001). Japanese and White women had a similar number of oocytes retrieved with no significant differences among all women who started stimulation (9.3 ± 5.4 versus 9.5 ± 5.7), potential low responders (7.2 ± 3.7 versus 7.6 ± 4.6) or potential high responders (10.8 ± 5.9 versus 11.0 ± 6.0). At each level of ovarian response, serum oestradiol concentrations were significantly higher in Japanese women (P = 0.024). The incidence of early ovarian hyperstimulation syndrome was significantly higher in Japanese women compared with White women; overall (10.0% versus 2.2%, P = 0.0124) and at similar serum oestradiol concentrations (P = 0.0137).

CONCLUSIONS

The individualized follitropin delta dosing provides similar serum FSH concentrations and similar oocyte yield in Japanese and White IVF/ICSI patients, but the oestradiol response is higher in Japanese women.

Low Serum LH Levels During Ovarian Stimulation With GnRH Antagonist Protocol Decrease the Live Birth Rate After Fresh Embryo Transfers but Have No Impact in Freeze-All Cycles

OBJECTIVE

To explore the association between serum LH levels and the cumulative live birth rate (CLBR) within one complete cycle, and the impact of serum LH levels on the live birth rate (LBR) after the initial embryo transfer (ET) considering different ET strategies (fresh or freeze-all).

DESIGN

A retrospective cohort study.

SETTING

University-affiliated reproductive center.

PATIENTS

1480 normogonadotrophic women who underwent COS with GnRH antagonist protocol for the first IVF/ICSI attempt.

INTERVENTIONS

The sample was stratified into low and higher LH groups according to serum LH peak levels of <4 (Group A) and ≥4 IU/L (Group B) during COS. Patients were also sub-grouped into conventional fresh/frozen ET cycles and freeze-all cycles.

MAIN OUTCOME MEASURES

The LBR after the initial embryo transfer and the CLBR within one complete cycle.

SECONDARY OUTCOME MEASURES

The numbers of day-3 high-quality embryos, the numbers of embryos available, and the other pregnancy outcomes after the initial ET.

RESULTS

In the whole cohort, the CLBRs decreased significantly in the low (63.1% vs. 68.3%, P=.034) LH group compared to the higher LH group. Subgroup analysis revealed that patients with low LH levels had lower LBR after fresh ET (38.0% vs. 51.5%, P=.005) but comparable LBR after the first frozen-thawed ET (FET) in freeze-all cycles (49.8% vs. 51.8%, P=.517) than patients with higher LH peak levels. Likewise, patients with low LH levels had lower CLBR for conventional fresh/frozen ET cycles (54.8% vs. 66.1%, P=.015) but comparable CLBR for the freeze-all cycles (66.8% vs. 69.2%, P=.414) than those with higher LH levels. Following confounder adjustment, multivariable regression analyses showed that low LH level was an independent risk factor for the CLBR in the whole cohort (odds ratio (OR): 0.756, 95% confidence interval (CI): 0.604-0.965, P=.014) and in patients who underwent the conventional ET strategy (OR: 0.596, 95% CI: 0.408-0.917, P=.017). Moreover, the adverse impact of low LH levels on LBRs maintained statistically significant after fresh transfers (OR: 0.532, 95% CI: 0.353-0.800, P=.002) but not after the first FETs in freeze-all cycles (OR: 0.918, 95% CI: 0.711-1.183, P=.508).

CONCLUSIONS

In comparison with higher LH levels, low LH levels decrease the CLBRs per oocyte retrieval cycle for normogonadotrophic women who underwent COS using GnRH antagonists. This discrepancy may arise due to the significant detrimental effect of low LH levels on the LBRs after fresh embryo transfers.

The association between treatment parameters on the day of gonadotropin-releasing hormone antagonist initiation during a flexible protocol and oocyte maturation rate

This study aimed to evaluate the effects of different treatment parameters on the day of GnRH antagonist initiation on oocyte maturation rate. We performed a retrospective cohort study of women aged ≤ 38 who underwent their first IVF-ICSI treatment using a flexible GnRH antagonist protocol in a single university-affiliated medical center during 2005-2015. Treatment parameters of three groups of oocyte maturation rates (<60%, 60-90%,>90%) were compared. Multivariate analysis was conducted to detect an association between treatment parameters on the day of GnRH antagonist initiation and oocyte maturation rate. The cohort included 458 patients, of whom 180 (39%) had a high oocyte maturation rate (≥90%), 211 (46%) had an oocyte maturation rate between 60-90% and 67 (15%) had a low maturation rate (≤60%). Women with a high maturation rate had longer duration of treatment (10.3 ± 2.9 days vs. 9.6 ± 2.5 vs. 9.5 ± 3.2, P = 0.019), lower levels of estradiol (1985 ± 1357 vs. 2406 ± 1666 vs. 2325 ± 1811, P = 0.027) and lower estradiol/maximal follicular diameter ratio on the day of GnRH antagonist initiation (137 ± 89 vs. 165 ± 103 vs. 163 ± 125, P = 0.019) as compared to women with medium and low maturation rates, respectively. Using linear regression multivariate analysis, lower estradiol and lower estradiol/maximal follicular diameter ratio on GnRH antagonist initiation day were associated with higher oocyte maturation rate. Further prospective studies to determine the best timing for GnRH antagonist initiation are needed.

In ovaries with high or low variation in follicle size, granulosa cells of antral follicles exhibit distinct size-related processes

Antral follicle size might be a valuable additive predictive marker for IVF outcome. To better understand consequences of antral follicle size as a marker for reproductive outcome, we aimed to obtain insight in follicle size-related granulosa cell processes, as granulosa cells play an essential role in follicular development via the production of growth factors, steroids and metabolic intermediates. Using the pig as a model, we compared gene expression in granulosa cells of smaller and larger follicles in the healthy antral follicle pool of sows, which had a high variation versus low variation in follicle size. Selected gene expression was confirmed at the protein level. Granulosa cells of smaller antral follicles showed increased cell proliferation, which was accompanied by a metabolic shift towards aerobic glycolysis (i.e. the Warburg effect), similar to other highly proliferating cells. High granulosa cell proliferation rates in smaller follicles might be regulated via increased granulosa cell expression of the androgen receptor and the epidermal growth factor receptor, which are activated in response to locally produced mitogens. While granulosa cells of smaller follicles in the pool are more proliferative, granulosa cells of larger follicles express more maturation markers such as insulin-like growth factor-1 (IGF1) and angiopoietin 1 (ANGPT1) and are therefore more differentiated. As both higher IGF1 and ANGPT1 have been associated with better IVF outcomes, the results of our study imply that including smaller follicles for oocyte aspiration might have negative consequences for IVF outcome.