The effect of polymorphisms in FSHR gene on late follicular phase progesterone and estradiol serum levels in predicted normoresponders

STUDY QUESTION

Does the presence of FSHR single-nucleotide polymorphisms (SNPs) affect late follicular phase progesterone and estradiol serum levels in predicted normoresponders treated with rFSH?

SUMMARY ANSWER

The presence of FSHR SNPs (rs6165, rs6166, rs1394205) had no clinically significant impact on late follicular phase serum progesterone and estradiol levels in predicted normoresponders undergoing a GnRH antagonist protocol with a fixed daily dose of 150 IU rFSH.

WHAT IS KNOWN ALREADY

Previous studies have shown that late follicular phase serum progesterone and estradiol levels are significantly correlated with the magnitude of ovarian response. Several authors have proposed that individual variability in the response to ovarian stimulation (OS) could be explained by variants in FSHR. However, so far, the literature is scarce on the influence of this genetic variability on late follicular phase steroidogenic response. Our aim is to determine whether genetic variants in the FSHR gene could modulate late follicular phase serum progesterone and estradiol levels.

STUDY DESIGN, SIZE, DURATION

In this multicenter multinational prospective study conducted from November 2016 to June 2019, 366 patients from Vietnam, Belgium and Spain (166 from Europe and 200 from Asia) underwent OS followed by oocyte retrieval in a GnRH antagonist protocol with a fixed daily dose of 150 IU rFSH. All patients were genotyped for 3 FSHR SNPs (rs6165, rs6166, rs1394205) and had a serum progesterone and estradiol measurement on the day of trigger.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Included patients were predicted normal responder women <38 years old undergoing their first or second OS cycle. The prevalence of late follicular phase progesterone elevation (PE), as well as mean serum progesterone and estradiol levels on the day of trigger were compared between the different FSHR SNPs genotypes. PE was defined as >1.50 ng/ml.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall prevalence of PE was 15.8% (n = 58). No significant difference was found in the prevalence of PE in Caucasian and Asian patients (17.5% versus 14.5%). Estradiol levels on the day of trigger and the number of retrieved oocytes were significantly higher in patients with PE (4779 ± 6236.2 versus 3261 ± 3974.5 pg/ml, P = 0.003, and 16.1 ± 8.02 versus 13.5 ± 6.66, P = 0.011, respectively). Genetic model analysis, adjusted for patient age, body mass index, number of retrieved oocytes and continent (Asia versus Europe), revealed a similar prevalence of PE in co-dominant, dominant and recessive models for variants FSHR rs6166, rs6165 and rs1394205. No statistically significant difference was observed in the mean late follicular phase progesterone serum levels according to the genotypes of FSHR rs6166 (P = 0.941), rs6165 (P = 0.637) and rs1394205 (P = 0.114) in the bivariate analysis. Also, no difference was found in the genetic model analysis regarding mean late follicular phase progesterone levels across the different genotypes. Genetic model analysis has also revealed no statistically significant difference regarding mean estradiol levels on the day of trigger in co-dominant, dominant and recessive models for variants FSHR rs6166, rs6165 and rs1394205. Haplotype analysis revealed a statistically significant lower estradiol level on the day of trigger for rs6166/rs6165 haplotypes GA, AA and GG when compared to AG (respectively, estimated mean difference (EMD) -441.46 pg/ml (95% CI -442.47; -440.45), EMD -673.46 pg/ml (95% CI -674.26; -672.67) and EMD -582.10 pg/ml (95% CI -584.92; -579.28)). No statistically significant differences were found regarding the prevalence of PE nor late follicular phase progesterone levels according to rs6166/rs6165 haplotypes.

LIMITATIONS, REASONS FOR CAUTION

Results refer to a population of predicted normal responders treated with a normal/low fixed dose of 150 IU rFSH throughout the whole OS. Consequently, caution is needed before generalizing our results to all patient categories.

WIDER IMPLICATIONS OF THE FINDINGS

Based on our results, FSHR SNPs rs6165, rs6166 and rs1394205 do not have any clinically significant impact neither on late follicular phase serum progesterone nor on estradiol levels in predicted normal responders. These findings add to the controversy in the literature regarding the impact of individual genetic susceptibility in response to OS in this population.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by an unrestricted grant by Merck Sharp & Dohme (MSD, IISP56222). N.P.P. reports grants and/or personal fees from MSD, Merck Serono, Roche Diagnostics, Ferring International, Besins Healthcare, Gedeon Richter, Organon, Theramex and Institut Biochimique SA (IBSA). C.A. reports conference fees from Merck Serono, Medea and Event Planet. A.R.N., C.B., C.S., P.Q.M.M., H.T., C.B., N.L.V., M.T.H. and S.G. report no conflict of interests related to the content of this article.

TRIAL REGISTRATION NUMBER

NCT03007043.

Varying levels of serum estradiol do not alter the timing of the early endometrial secretory transformation

STUDY QUESTION

Do supraphysiologic estradiol (E2) levels in the ranges attained during normal and high response superovulation cycles modify the onset of endometrial secretory transformation?

SUMMARY ANSWER

Highly supraphysiologic levels of E2 do not alter the ability of physiologic levels of progesterone (P4) to induce secretory transformation.

WHAT IS KNOWN ALREADY

Previous studies have demonstrated that premature P4 elevations during IVF cycles are associated with a decrement in clinical pregnancy rates after fresh embryo transfer due to shifts in the window of implantation (WOI). However, alterations in the onset of secretory transformation may not apply uniformly to all patients. High responders with supraphysiologic E2 levels accompanied by similar subtle increases in P4 have not been shown to have decreased sustained implantation rates. This prospective investigation in which whole-genome transcriptomic and methylomic analysis of the endometrium is performed for individual patients under a range of E2 concentrations brings clarity to a long-debated issue.

STUDY DESIGN, SIZE, DURATION

A randomized, prospective and paired trial was conducted in which 10 participants were enrolled and randomized to the order in which they completed three distinct uterine stimulation cycles, each at a specific E2 concentration: physiologic (∼180 pg/ml), moderately supraphysiologic (600-800 pg/ml) or supraphysiologic (2000 pg/ml). Target E2 ranges were selected to mimic those seen in natural, controlled ovarian stimulation and IVF cycles. E2 valerate was administered in order to maintain stable E2 levels for 12 days followed by intramuscular P4 in oil 10 mg/day for two doses, after which an endometrial biopsy was performed. A total of 30 endometrial biopsies were included in a whole-genome transcriptomic and methylomic analysis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Healthy volunteers without a history of infertility were included in this study at a single large infertility center. DNA was isolated from the endometrial biopsy specimens and bisulfite sequencing was performed to construct a methylation array. Differential methylation analysis was conducted based on differences in M-values of individuals across treatment groups for each probe as well as carrying out t-tests. RNA was isolated for RNA-Seq analysis and gene expression values were compared using DESeq2. All analyses were performed in a pairwise fashion to compare among the three stimulation cycles within individuals and secondarily to compare all participants in each of the cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean peak E2 and P4 levels were 275 pg/ml and 4.17 ng/ml in the physiologic group, 910 pg/ml and 2.69 ng/ml in the moderate group was, and 2043 pg/ml and 2.64 ng/ml in the supraphysiologic group, respectively. Principal component analysis of 834 913 CpG sites was performed on M-values of individuals within the low, moderate and supraphysiologic conditions in a paired approach. There were no differences in genome-wide methylation within participants across E2 groups. A paired analysis revealed that gene expression profiles did not differ within the same individual at each of the three E2 levels. No significant alterations in gene expression as related to endometrial physiology were identified between the low, moderate and supraphysiologic groups in an inter-participant analysis.

LIMITATIONS, REASONS FOR CAUTION

Although each participant completed a physiologic cycle in which E2 levels were maintained in a range that would simulate a natural cycle, our findings are limited by lack of an unmedicated control to assess if there was a potential effect from E2V. Additionally, our results were obtained in fertile individuals, who may have a different endometrial response compared to an infertile population. Despite the whole genomic endometrial assessment and rigorous, paired study design, the sample size was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Given that the endometrial response to P4 is unaffected by E2 levels in the supraphysiologic range, diminutions in implantation seen in stimulated cycles may result from embryonic-endometrial dyssynchrony following early P4 elevations or slowly blastulating embryos, which occur independently of the magnitude of the E2 rise.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Foundation for Embryonic Competence, Basking Ridge, NJ, USA. Dr E.S. reports consultancy work for The Foundation for Embryonic Competence, Basking Ridge, NJ, USA. The other authors declare no conflict of interests related to this topic.

TRIAL REGISTRATION NUMBER

NCT02458404.

Binding of microRNA-135a (miR-135a) to homeobox protein A10 (HOXA10) mRNA in a high-progesterone environment modulates the embryonic implantation factors beta3-integrin (ITGβ3) and empty spiracles homeobox-2 (EMX2)

Background

Patients with elevated circulating progesterone concentrations on the day of the human chorionic gonadotropin (hCG) trigger had relatively low implantation rates during assisted reproductive treatments. In this study, we assess the hypothesis that different concentrations of progesterone regulate the expression of homeobox protein A10 (HOXA10) and its downstream genes through miRNA-135a.

Methods

MicroRNA-135a (miR-135a), HOXA10, beta3-integrin (ITGβ3), and empty spiracles homeobox-2 (EMX2) expression levels in endometrial tissues from patients with elevated progesterone were measured. To determine the threshold of progesterone level which can impair implantation, Ishikawa cells were used to determine the expression of the aforementioned 4 genes after exposure to 5 graded concentrations of progesterone. The dual-luciferase reporter assay was used to verify whether miR-135a regulated the expression of HOXA10. Furthermore, the effects of HOXA10 on the expression of key endometrial receptivity genes ITGβ3 and EMX2 were confirmed.

Results

High progesterone levels promoted miR-135a expression in vivo, and miR-135a bound to the 3'-untranslated region (3'-UTR) of HOXA10 mRNA to inhibit HOXA10 expression. Reduction of HOXA10 promoted EMX2 expression and inhibited ITG-3 production. Progesterone promoted the expression of HOXA10 in vitro at low concentrations. However, when the concentration was greater than 10⁻⁷ ng/mL, progesterone inhibited HOXA10 by promoting miR-135a expression, thereby altering the expression of related genes and affecting endometrial receptivity.

Conclusions

In vitro, the trend in miR-135a expression (which first decreased and then increased) was in direct contrast to that of HOXA10 expression (which first increased and then decreased) as progesterone levels increased. The key factors regulating endometrial receptivity included ITGβ3 and EMX2, which were confirmed to be regulated by HOXA10. High progesterone levels affected miR-135a expression, and miR-135a inhibited HOXA10 expression, thereby affecting endometrial receptivity.

Step-Down of FSH- Dosage During Ovarian Stimulation - Basic Lessons to Be Learnt From a Randomized Controlled Trial

A rise in serum progesterone in the late follicular phase is a well described adverse effect of ovarian stimulation for IVF/ICSI. Previous data suggest, that enhanced gonadotropin stimulation causes progesterone elevation and the incidence of premature progesterone elevation can be reduced by declining gonadotropin dosages. This randomized controlled trial (RCT) aimed to achieve a significant reduction of the progesterone level on the day of final oocyte maturation by a daily reduction of 12.5 IU rec-FSH from a follicle size of 14 mm in a GnRH-antagonist protocol. A total of 127 patients had been recruited (Control group (CG): 62 patients; Study group (SG): 65 patients). Due to drop out, data from 108 patients (CG: 55 patients; SG: 53 patients) were included into the analysis. Patients' basic parameters, gonadotropin (Gn)-starting dose, total Gn-stimulation dosage, the number of retrieved and mature oocytes as well as in the hormonal parameters on the day of trigger (DoT) were not statistically significantly different. However, through stepwise Gn-reduction of 12.5 IU/day in the SG, there was a statistically highly significant difference in the Gn-stimulation dosage on the day of trigger (p < 0.0001) and statistically significant associations for the DoT-P4-levels with the DoT-FSH-levels for both groups (CG: p = 0.001; SG: p = 0.0045). The herein described significant associations between DoT-P4-levels and DoT-FSH-levels confirm the theory that enhanced FSH stimulation is the primary source of progesterone elevation on the day of final oocyte maturation in stimulated IVF/ICSI cycles. Given the pathophysiologic mechanism of progesterone elevation during ovarian stimulation, the use of an increased FSH step-down dosage should be studied in future RCTs, despite the fact that a step-down approach of daily 12.5 IU rec-FSH did not achieve a significantly reduced progesterone level on the DoT. Clinical Trial Registration: clinicaltrials.gov, identifier NCT03356964.

Early Progesterone Change Associated With Pregnancy Outcome After Fresh Embryo Transfer in Assisted Reproduction Technology Cycles With Progesterone Level of >1.5 ng/ml on Human Chorionic Gonadotropin Trigger Day

Several studies have reported a poor implantation rate for assisted reproduction technology (ART) cycles with elevated progesterone (P4) at the end of the follicular phase. Whether all women with increased P4 on the human chorionic gonadotropin(hCG) trigger day should undergo fresh or frozen embryo transfer (ET) remains to be explored. This study attempted to determine that the P4 level on 2 days before hCG administration and P4 ratio can serve as indicators for fresh ET in normal responders with an elevated P4 level of >1.5 ng/ml on the hCG administration day. This was a retrospective cohort study involving 337 ART cycles with fresh ET for normal responders. Serum P4 levels were measured 2 days prior to hCG day (P4 level I) and on the hCG administration day (P4 level II). The P4 ratio was calculated as follows: P4 ratio = P4 level II / P4 level I. The primary outcome is live birth rate of fresh ET cycles. The ROC curves established that the optimal P4 level I and P4 ratio for pregnancy in ART cycles with high P4 level II were 0.975 ng/ml and 1.62, respectively. Patients with a P4 level I of ≤0.975 ng/ml and P4 ratio of >1.62 were associated with a significantly higher implantation (30.8%, 61/198 vs. 10.3%, 19/184, p < 0.001) and live birth rates (51.6%, 33/64 vs. 15.0%, 9/60, p < 0.001) compared with those with a P4 level I of >0.975 ng/ml and P4 ratio of ≤1.62. A combination of P4 level I and P4 ratio cutoff values of 0.975 ng/ml and 1.62, respectively, had a positive predictive value (PPV) of 82.5% for pregnancy. In conclusion, fresh ET can be an option for women with an early P4 level I under 0.975 ng/ml and a P4 ratio higher than 1.62, especially for those normal responders with an elevated P4 level II >1.5 ng/ml on the hCG administration day. This approach may shorten the time to pregnancy and reduce the cost of ART cycles.

The Role of hCG Triggering Progesterone Levels: A Real-World Retrospective Cohort Study of More Than 8000 IVF/ICSI Cycles

Objective: To assess the association between serum ovulation trigger progesterone (P) levels and the outcome of in vitro fertilization cycles. Design Setting: Real world single-center retrospective cohort study. Patient Intervention(s): All fresh cleavage and blastocyst-stage embryo transfers (ETs) performed from January 2012 to December 2016. Main outcome Measure(s): The impact of premature high serum P levels cycles in terms of clinical pregnancy rates (CPRs) and live birth rates (LBRs). Results: 8,034 ETs were performed: 7,597 cleavage-stage transfers and 437 blastocyst transfers. Serum P levels demonstrated to be inversely related to CPR (OR 0.72, p < 0.001) and LBR (OR 0.73, p < 0.001). The progressive decrease of LBR and CPR started when P levels were >1 ng/ml in a good prognosis cleavage ET subgroup, whereas in patients with worse prognosis only for P ≥ 1.75 ng/ml. In the blastocyst ET subgroup, the negative effect of P elevation was reported only if P was >1.75 ng/ml. CPR (OR 0.71 (0.62-0.80), p < 0.001) and LBR (OR 0.73 (0.63-0.84), p < 0.001) in thawed cycles resulted statistically significantly higher than in fresh cycles in the cleavage-stage subgroup. In the blastocyst group, no significant difference resulted between thawed and fresh cycles, independently of P levels [CPR OR 0. 37 (0.49-1.09), p = 0.123; LBR OR 0.71 (0.46-1.10), p = 0.126]. Conclusion: High P levels decrease CPR as well as LBR in both cleavage and blastocyst ET. In the cleavage group, for P levels below 1.75 ng/ml, our data suggest the possibility to wait until day 5 for ET, and if P level is ≥1.75 ng/ml, it should be considered to freeze all embryos and postpone the ET. Clinical Trial Registration: ClinicalTrials.gov, ID: NCT04253470.

No influence of the indication of freeze-all strategy on subsequent outcome to frozen-thawed embryo transfer cycle

BACKGROUND

Freezing all embryos generated during an IVF/ICSI attempt is used increasingly as a strategy to optimize results. We investigated whether we could find differences in outcome between subpopulations of patients undergoing the so-called "freeze all" procedure.

METHODS

Non-interventional, observational, retrospective study of 131 freeze-all cycles performed between July 2015 and December 2016 at the University Hospital of Ghent (Belgium). Freeze-all indications were categorized in 4 groups: group 1, high progesterone level (PE) on the day of hCG administration defined as >1.5 ng/ml (n= 50); group 2, risk of Ovarian Hyperstimulation Syndrome (OHSS) (n=38); group 3, partner donation in lesbian couples (n=23) and group 4, a miscellany of other reasons (n=20). Clinical pregnancy with fetal heart beat after the first thawed embryo transfer (ET) after ovum pick-up and cumulative clinical pregnancy rate per attempt were used as primary outcome variables.

RESULTS

Clinical pregnancy rate (CPR) with fetal heart beat in the first thawed ET and cumulative clinical pregnancy rate per cycle (CCPR) were not statistically different between the four groups. In the group of PE a cumulative clinical pregnancy rate was observed of 40,5%, this in comparison to the 3 other groups involving risk of OHSS (66,7%), partner donation (61,1%) and other reasons (57,1%). More rFSH was used in the group with Progesterone elevation (PE) (P=0.04), as described earlier in the literature.

CONCLUSION

Our findings indicate comparable (cumulative) clinical pregnancy rates per attempt between the four groups of freeze-all indications.

Association Between Progesterone Elevation on the Day of Human Chronic Gonadotropin Trigger and Pregnancy Outcomes After Fresh Embryo Transfer in In Vitro Fertilization/Intracytoplasmic Sperm Injection Cycles

Progesterone elevation (PE) during the late follicular phase of controlled ovarian stimulation in fresh embryo transfer in vitro fertilization (IVF)/intracytoplasmic sperm injection cycles has been claimed to be associated with decreased pregnancy rates. However, the evidence is not unequivocal, and clinicians still have questions about the clinical validity of measuring P levels during the follicular phase of stimulated cycles. We reviewed the existing literature aimed at answering four relevant clinical questions, namely (i) Is gonadotropin type associated with PE during the follicular phase of stimulated cycles? (ii) Is PE on the day of human chorionic gonadotropin (hCG) associated with negative fresh embryo transfer IVF/intracytoplasmic sperm injection (ICSI) cycles outcomes in all patient subgroups? (iii) Which P thresholds are best to identify patients at risk of implantation failure due to PE in a fresh embryo transfer? and (iv) Should a freeze all policy be adopted in all the cycles with PE on the day of hCG? The existing evidence indicates that late follicular phase progesterone rise in gonadotropin releasing analog cycles is mainly caused by the supraphysiological stimulation of granulosa cells with exogenous follicle-stimulating hormone. Yet, the type of gonadotropin used for stimulation seems to play no significant role on progesterone levels at the end of stimulation. Furthermore, PE is not a universal phenomenon with evidence indicating that its detrimental consequences on pregnancy outcomes do not affect all patient populations equally. Patients with high ovarian response to control ovarian stimulation are more prone to exhibit PE at the late follicular phase. However, in studies showing an overall detrimental effect of PE on pregnancy rates, the adverse effect of PE on endometrial receptivity seems to be offset, at least in part, by the availability of good quality embryo for transfer in women with a high ovarian response. Given the limitations of the currently available assays to measure progesterone at low ranges, caution should be applied to adopt specific cutoff values above which the effect of progesterone rise could be considered detrimental and to recommend "freeze-all" based solely on pre-defined cutoff points.

Controlled ovarian hyperstimulation with sequential letrozole co-treatment in normo/high responders

OBJECTIVE

To investigate the effect of co-administration of letrozole in an ovarian stimulation protocol using recombinant FSH and GnRH antagonists for ICSI in normo/high responders.

METHODS

Computerized data of 320 antagonist ICSI/ET cycles with or without letrozole were retrospectively analyzed. In 105 cases, letrozole (5 mg/day) was started at the second day of the cycle continued for 5 days. At the second day of letrozole, gonadotropins were added. The remaining 215 cases were stimulated with recombinant FSH only. In all cases on day 6, GnRH antagonist was started. Ovarian stimulation protocols with or without letrozole were compared for cycle outcome parameters.

RESULTS

In cycles with letrozole, significantly lower gonadotropin consumption and lower peak estradiol levels were found. In cycles with letrozole, mean number of metaphase II and fertilized oocytes retrieved were significantly higher compared to cycles without letrozole. The pregnancy and clinical pregnancy rates were similar.

CONCLUSION

Should the number of oocytes retrieved being higher in letrozole group might indicate that letrozole might contribute to successful ovarian stimulation with a lower dosage of gonadotropins. Despite the lower peak estradiol levels, pregnancy rates being similar to other group also support the idea that letrozole can contribute to normal potential of implantation.

Human steroidogenesis: implications for controlled ovarian stimulation with exogenous gonadotropins

In the menstrual cycle, the mid-cycle surge of gonadotropins (both luteinising hormone [LH] and follicle-stimulating hormone [FSH]) signals the initiation of the periovulatory interval, during which the follicle augments progesterone production and begins to luteinise, ultimately leading to the rupture of the follicle wall and the release of an oocyte. The administration of gonadotropins in controlled ovarian stimulation (COS) leads to supraphysiological steroid concentrations of a very different profile compared with those seen during natural cycles. It has been suggested that these high steroid concentrations cause alterations in endometrial development, affecting oocyte viability in assisted reproductive technology. Furthermore, it has been proposed that elevated progesterone levels have a negative effect on the reproductive outcome of COS. This may arise from an asynchrony between embryo stage and endometrium status at the window of implantation. The regulation of progesterone production by the developing follicles during COS is a complicated interplay of hormonal systems involving the theca and granulosa cells, and the effect of the actions of both LH and FSH. The present paper reviews current knowledge of the regulation of progesterone in the human ovary during the follicular phase and highlights areas where knowledge remains limited. In this review, we provide in-depth information outlining the regulation and function of gonadotropins in the complicated area of steroidogenesis. Based on current evidence, it is not clear whether the high levels of progesterone produced during COS have detrimental effects on fertility.