FSH receptor gene polymorphisms have a role for different ovarian response to stimulation in patients entering IVF/ICSI-ET programs

Current Status of Ovarian and Endometrial Biomarkers in Predicting ART Outcomes

This review evaluates the role of ovarian and endometrial biomarkers in predicting outcomes in assisted reproductive technology (ART). It highlights established ovarian biomarkers such as the anti-Müllerian hormone (AMH) and follicle-stimulating hormone (FSH), alongside emerging ones like growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), connexin, and granulosa cell gene profiles. Additionally, the paper explores endometrial biomarkers such as ERA, BCL6, and immune markers, as well as the potential for genomic and proteomic technologies in customizing implantation. It concludes that while many of these biomarkers show promise, their clinical integration requires rigorous research and validation to confirm their safety and utility in ART.

Follicle-Stimulating Hormone Receptor (FSHR) Ser680Asn Genotype Does Not Affect the Follicular Fluid Hormonal Profile in Stimulated Cycles Using Different Gonadotropin Preparations for Ovulation Induction: A Pilot Study

BACKGROUND

The existing literature lacks consensus on the effectiveness of utilizing polymorphisms to enhance outcomes in in vitro fertilization (IVF), particularly regarding ovulation induction protocols, oocyte and embryo quality, and pregnancy rates. Therefore, the present pilot study aims to assess whether the composition of different gonadotropin preparations affects the ovarian stimulation protocol concerning follicle-stimulating hormone receptor (FSHR) Ser680Asn genotypes (Ser/Ser, Ser/Asn, and Asn/Asn), in terms of ovulation induction parameters, including oocyte maturation rate, embryo quality, and pregnancy rate.

METHODOLOGY

A total of 94 IVF patients underwent treatment using a GnRH antagonist protocol with four distinct gonadotropin preparations: HMG, HMG/hCG, rFSH, and rFSH/hCG. Follicular fluid (FF) samples were pooled for each patient for analysis.

RESULTS

No statistical differences in the FF hormonal profile (progesterone, testosterone, androstenedione, estradiol, FSH, hCG) among the FSHR genotypes were reported either separately for each protocol or in combination for the four different preparations of gonadotropins. The maturation rate of MII oocytes and embryo quality did not differ among women carrying either Ser/Ser, Ser/Asn, or Asn/Asn genotype (p-value=0.475, and p-value=1.000, respectively). Moreover, no statistically significant correlation was revealed among Ser/Ser, Ser/Asn, and Asn/Asn carriers and pregnancy rate (p = 0.588).

CONCLUSIONS

FF hormonal analysis of women undergoing IVF using different ovulation induction protocols and carrying either Ser/Ser, Ser/Asn, or Asn/Asn genotype revealed no significant correlations, in terms of maturation rate of MII oocytes, embryo quality, and pregnancy rate, indicating that the FSHR Ser680Asn genotype does not constitute a biomarker for a positive pregnancy outcome. Therefore, the existence of a different mechanism for the expression of FSHR Ser680Asn genotypes in the FF hormonal profile related to stimulated cycles is implied.

Association of FSHR gene polymorphisms with poor ovarian response in patients undergoing IVF: A systematic review and meta-analysis

BACKGROUND

The results of studies on the association between polymorphisms in the FSHR gene and the risk of POR undergoing IVF have been inconsistent with each other, so we conducted a meta-analysis of all the available studies to explore the association between polymorphisms in the FSHR gene and the risk of POR.

METHODS

Literature that met the inclusion criteria was collected by searching six electronic databases and basic data from included studies were extracted. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the strength of association between follicle-stimulating hormone receptor (FSHR) gene polymorphism and poor ovarian response (POR) risk. Begg's and Egger's tests were used to determine whether there was publication bias, and sensitivity analysis and TSA analysis were used to verify the stability and reliability of the results.

RESULTS

We included 24 articles, 22 of which explored rs6166, including 2,206 cases and 3,897 controls. 6 articles explored rs6165, including 444 cases and 875 controls. Under additive, heterozygote, and dominant models, rs6166 was significantly associated with POR (S vs. N: OR = 1.29, 95 % CI = 1.05-1.59, P = 0.017; NS vs. NN: OR = 1.33, 95 % CI = 1.02-1.74, P = 0.038; NS + SS vs. NN: OR = 1.38, 95 % CI = 1.04-1.84, P = 0.025). In ethnicity-based subgroup analyses, the additive, homozygote, heterozygote, and dominant models increased Asian POR risk. Among the five genetic models, rs6165 was significantly associated with POR (T vs. C: OR = 1.64, 95 % CI = 1.25-2.16, P = 0.000; TT vs. CC: OR = 2.76, 95 % CI = 1.43-5.32, P = 0.003; CT vs. CC: OR = 1.58, 95 % CI = 1.19-2.10, P = 0.001; TT vs. CC + CT: OR = 2.32, 95 % CI = 1.67-3.23, P = 0.000; CT + TT vs. CC: OR = 1.80, 95 % CI = 1.22-2.65, P = 0.003). In ethnicity-based subgroup analyses, all five genetic models increased the risk of POR in Caucasians.

CONCLUSION

According to the current meta-analysis, the rs6166 S allele was significantly associated with an increased risk of POR, especially in Asian populations. The rs6165 T allele was significantly associated with an increased risk of POR, especially in Caucasian populations.

The prospect of artificial intelligence to personalize assisted reproductive technology

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

Luteal phase stimulation in double ovarian stimulation cycles is not affected by the follicle-stimulating hormone (FSH) receptor genotype: double ovarian stimulation is beneficial independently of the genotype at position 680 of the follicle-stimulating hormone receptor

OBJECTIVES

To determine whether follicle-stimulating hormone receptor (FSHR) genotype influences the outcome of ovarian stimulation treatment in luteal phase.

METHODS

A total of 299 patients were included in a retrospective study between July 2017 and December 2021. These patients carried out a double stimulation protocol and the variant Asn680Ser (rs6166; c.2039A>G) of FSH receptor was genotyped either as part of the pre-treatment fertility tests or for the current study. Patients undergoing a double stimulation treatment who could not be genotyped were excluded from this analysis.

RESULTS

The results obtained from ovarian stimulation in luteal phase were better than those obtained in conventional follicular phase. Statistically significant differences ( P  < 0.001) were found in the number of retrieved oocytes (5.47 vs. 4.18), retrieved MII (4.52 vs. 3.29) and fertilised oocytes (3.81 vs. 2.20). Furthermore, these differences remained regardless of the FSH receptor genotype for the 680 position in all groups ( P  < 0.05). In addition, stimulation in luteal phase lasts longer and requires more gonadotropins than in follicular phase. This is especially noteworthy in patients with Ser/Ser genotype, who required a slightly higher dose of gonadotropins compared to other genotypes in luteal phase, as previously observed in the follicular phase for this genotype. No significant differences in age, anti-Müllerian hormone levels, antral follicle count, BMI and type of trigger used in luteal phase were observed among groups of patients with different FSH receptor genotypes.

CONCLUSION

All patients undergoing IVF seem to benefit from luteal phase ovarian stimulation, regardless of their FSHR genotype.

Association Between Follicle-Stimulating Hormone Receptor (FSHR) rs6166 and Estrogen Receptor 1 (ESR1) rs2234693 Polymorphisms and Polycystic Ovary Syndrome Risk, Phenotype, and Reproductive Outcomes in an Infertile Portuguese Population

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common endocrine disorder often leading to anovulatory infertility. PCOS pathophysiology is still unclear and several potential genetic susceptibility factors have been proposed. The effect of polymorphisms in two genesrelated to follicular recruitment and development, the follicle-stimulating hormone receptor (FSHR) and the estrogen receptor 1 (ESR1), have been studied in different populations with contradictory results.

AIMS

To evaluate the influence of FSHR rs6166 (c.2039A>G) and of ESR1 rs2234693 (Pvull c.453-397 T > C) polymorphisms on PCOS risk, phenotype, and response to controlled ovarian stimulation (COS).

MATERIALS AND METHODS

Genotyping of the FSHR rs6166 and the ESR1 rs2234693 polymorphisms was performed in PCOS women and a control group undergoing in vitro fertilization (IVF). Demographic, clinical, and biochemical data, genotype frequency, and IVF outcomes were compared between groups.

RESULTS

We evaluated 88 PCOS women and 80 controls. There was no significant difference in the genotype distribution of FSHR rs6166 polymorphism between PCOS women and controls (AA 31.8%/AS 48.9%/SS 19.3% in PCOS women vs AA 37.5%/AS 40.0%/SS 22.5% in controls; p = 0.522). The same was true for the ESR1 rs2234693 (CC 24.1%/CT 46.0%/TT 29.9% in PCOS women vs CC 18.8%/CT 48.8%/TT 32.5% in controls; p = 0.697). In PCOS women, we found higher follicle-stimulating hormone (FSH) levels on the third day of the menstrual cycle associated with the SS variant of the FSHR polymorphism (9.2 vs 6.2 ± 1.6 and 5.6 ± 1.6 mUI/mL; p = 0.011). We did not find other associations between the baseline hormonal parameters, antral follicle count, and response measures to COS with FSHR or ESR1 genotypes. We found, however, a need for higher cumulative doses of FSH for COS in patients with the SS variant of the FSHR rs6166 polymorphism (1860.5 ± 627.8 IU for SSvs 1498.1 ± 359.3 for AA and 1425.4 ± 474.8 for SA; p = 0.046 and p = 0.046).

CONCLUSION

Our data suggest that in the population, FSHR rs6166and ESR1 rs2234693 polymorphisms do not influence the risk of developing PCOS nor do they influence the patient's phenotype and IVF success. However, the SS variant of the FSHR rs6166 polymorphism may be associated with FSH resistance requiring higher FSH doses for COS.

The Effect of the Allelics of Ser680Asn Polymorphisms of Follicle-Stimulating Hormone Receptor Gene in IVF/ICSI Cycles: a Systematic Review and Meta-analysis

A significant number of single-nucleotide polymorphisms (SNPs) of the follicle-stimulating hormone receptor (FSHr) can modify the response to exogenous FSH administration. A significant diversity in response to controlled ovarian stimulation (COS) in assisted reproductive technologies (ART) according to the type of allelic has been reported. We aimed to evaluate the relation between the Asn680Ser allelics and COS. A total of 4 electronic databases were searched for articles published up to August 2021. Prospective and retrospective comparative studies which reported outcomes after COS in patients who underwent genotyping for the detection of FSHr polymorphisms were considered eligible. A total of 11 studies including 4343 patients with Asn680Ser polymorphisms of the FSHr were included. Patients carrying the Asn/Asn allelic provide elevated E2 on the day of human chorionic gonadotropin (hCG) administration (1549 patients MD 262.39 pg/ml, p = 0.0007), but less transferrable embryos as compared with Ser/Ser genotype (283 patients MD - 0.11 embryos, p = 0.04). Ans/Ser versus Ser/Ser genotypes showed a higher E2 on the day of hCG administration (1799 patients, MD 207.86 pg/ml, p = 0.02). Pregnancy rates were similar in all combination of genotypes. There is currently no strong evidence suggesting that the examination of one gene in relation to genotypes can be effectively used as single tool to improve COS. However, polygenic analysis of different polymorphisms by analyzing the genetic profile of each individual could be useful. Further research is warranted to develop an algorithm that will enable simultaneous analysis of many genes, which combined with hormonal profile could promote treatment individualization.

Effect of Genetic Variants of Gonadotropins and Their Receptors on Ovarian Stimulation Outcomes: A Delphi Consensus

Background

A Delphi consensus was conducted to evaluate the influence of single nucleotide polymorphisms (SNPs) in genes encoding gonadotropin and gonadotropin receptors on clinical ovarian stimulation outcomes following assisted reproductive technology (ART) treatment.

Methods

Nine experts plus two Scientific Coordinators discussed and amended statements plus supporting references proposed by the Scientific Coordinators. The statements were distributed via an online survey to 36 experts, who voted on their level of agreement or disagreement with each statement. Consensus was reached if the proportion of participants agreeing or disagreeing with a statement was >66%.

Results

Eleven statements were developed, of which two statements were merged. Overall, eight statements achieved consensus and two statements did not achieve consensus. The statements reaching consensus are summarized here. (1) SNP in the follicle stimulating hormone receptor (FSHR), rs6166 (c.2039A>G, p.Asn680Ser) (N=5 statements): Ser/Ser carriers have higher basal FSH levels than Asn/Asn carriers. Ser/Ser carriers require higher amounts of gonadotropin during ovarian stimulation than Asn/Asn carriers. Ser/Ser carriers produce fewer oocytes during ovarian stimulation than Asn/Asn or Asn/Ser carriers. There is mixed evidence supporting an association between this variant and ovarian hyperstimulation syndrome. (2) SNP of FSHR, rs6165 (c.919G>A, p.Thr307Ala) (N=1 statement): Few studies suggest Thr/Thr carriers require a shorter duration of gonadotropin stimulation than Thr/Ala or Ala/Ala carriers. (3) SNP of FSHR, rs1394205 (-29G>A) (N=1 statement): Limited data in specific ethnic groups suggest that A/A allele carriers may require higher amounts of gonadotropin during ovarian stimulation and produce fewer oocytes than G/G carriers. (4) SNP of FSH β-chain (FSHB), rs10835638 (-211G>T) (N=1 statement): There is contradictory evidence supporting an association between this variant and basal FSH levels or oocyte number. (5) SNPs of luteinizing hormone β-chain (LHB) and LH/choriogonadotropin receptor (LHCGR) genes (N=1 statement): these may influence ovarian stimulation outcomes and could represent potential future targets for pharmacogenomic research in ART, although data are still very limited.

Conclusions

This Delphi consensus provides clinical perspectives from a diverse international group of experts. The consensus supports a link between some variants in gonadotropin/gonadotropin receptor genes and ovarian stimulation outcomes; however, further research is needed to clarify these findings.

Does Follicle-Stimulating hormone receptor polymorphism status affect In vitro fertilization-intracytoplasmic sperm injection results and live birth rate? A retrospective study

Background:

Follicle-stimulating hormone (FSH) plays a key role in fertility and shows its effect through the FSH receptor (FSHR), which is localized in cells.

Aims:

The aim of this study was to examine pregnancy outcomes and responses to controlled ovarian stimulation according to FSHR polymorphism types.

Study Setting and Design:

The study was retrospective, and included patients who applied to the University of Health Sciences Tepecik Training and Research Hospital in vitro fertilization (IVF) Unit during 2018 and 2019.

Materials and Methods:

Patients who underwent IVF-intracytoplasmic sperm injection and at the same time studied FSHR gene polymorphism in the genetic unit of our hospital were included in the study.

Statistical Analysis:

The Kruskal–Wallis test was used for multiple comparisons of continuous variables. The Chi-square test was used for categorical variables between groups.

Results:

A total of 143 patients who met our criteria were included in the study. 14% (n = 20) of the patients are also homozygous natural (Asn/Asn) type; 44.7% (n = 64) of the heterozygous mutant (Asn/Ser) type; 41.3% (n = 59) of them were homozygous mutant (Ser/Ser) type. There was no statistically significant difference between the groups in terms of pregnancy rate per started cycle, ongoing pregnancy per started cycle, ongoing pregnancy per embryo transfer and live birth per embryo transfer. A significant difference was observed between peak E2 and peak progesterone levels between Asn/Ser and Ser/Ser groups, and the levels of these hormones were lower in the Ser/Ser group (P = 0.018 and P = 0.016, respectively). Ovarian responses were classified as poor (≤3 oocytes), normal (4-20 oocytes) and hyperresponse (≥20 oocytes) according to the oocyte count. Accordingly, the number of patients with poor response was higher in the Ser/Ser group (P = 0.011).

Conclusions:

Ser/Ser polymorphism is characterised by a poor ovarian response. Despite this, polymorphisms in the FSHR gene do not seem to affect the results of pregnancy per started cycle, ongoing pregnancy per started cycle, ongoing pregnancy per embryo transfer and live birth per embryo transfer.

Recombinant luteinizing hormone supplementation in assisted reproductive technology: a review of literature

Background

Luteinizing hormone (LH) has the main role in ovarian function in both natural and artificial cycles. A normal LH concentration during controlled ovarian hyperstimulation is positively correlated to the number and quality of retrieved oocytes and resulting embryos.

Main body of the abstract

In this study, we reviewed whether rLH administration, adjunct to the ovarian stimulation regimen, could improve clinical outcomes. The literature review showed that rLH supplementation improves assisted reproductive technology (ART) outcomes among women with hypogonadotropic hypogonadism, and hyporesponsive women to follicle-stimulating hormone monotherapy. Besides, rLH supplementation has advantages for poor responder women 36–39 years of age. Even though the data suggested no priority regarding the LH source for improving ART outcome, women with different LH polymorphisms who did not respond similarly to ovarian stimulation may benefit from adjuvant rLH therapy.

Conclusion

rLH usage for improving ART outcome should be scrutinized via well-designed studies considering the subgroups of infertile women who benefit the most from rLH adjuvant therapy, the type of ovarian stimulation protocol to which rLH would be added, and also the exact dosage, as well as the proper timing (during or prior to a cycle).

Variants Ala307Ala and Ser680Ser of 307 and 680 FSHr polymorphisms negatively influence on assisted reproductive techniques outcome and determine high probability of non-pregnancy in Caucasian patients

PURPOSE

To determine the influence of different genotypes of Ala307Thr and Asn680Ser FSHr polymorphisms on controlled ovarian stimulation (COS) outcome and pregnancy.

METHODS

This study collected blood and physiological and clinical parameters of 517 Caucasian patients (Statistical power ≥ 80%) that underwent COS treatment. Genotypes of Ala307Thr and Asn680Ser polymorphisms were determined using PCR amplification followed by Bsu36I and BsrI digestion, respectively.

RESULTS

Ala307Ala and Ser680Ser genotypes associated to worse parameters of COS outcome (preovulatory follicles P = 0.05, in both), justifying their lower pregnancy rate than Non-Ala307Ala, P = 0.01 and Non-Ser680Ser, P = 0.004, respectively or together, (P = 0.003). Within the Non-Ala307Ala group, Thr307Thr genotype showed higher number of fertilized oocytes (P = 0.04) and embryos (P = 0.01) than Non-Thr307Thr, but no influence on pregnancy rate. Ala307Ala and Ser680Ser patients doubled probability of non-pregnancy than Non-Ala307Ala (odds ratio = 2.0) and Non-Ser680Ser (odds ratio = 2.11), respectively. Ala307Ala and Ser680Ser genotypes tend to appear together (P < 0.0001), which increases the probability of non-pregnancy.

CONCLUSIONS

Ala307Ala and Ser680Ser genotypes of 307 and 680 FSHr polymorphisms associate to worse COS outcome than its respective Non-Ala307Ala and Non-Ser680Ser. Within the Non-Ala307Ala genotypes, Thr307Thr, although shows higher Fertilized Oocytes and Embryos, do not influence on pregnancy rate. Ala307Ala and Ser680Ser genotypes double the probability of Non-Pregnancy than their respective Non-Ala307Ala and Non-Ser680Ser genotypes. Furthermore, the strong tendency of these genotypes to appear together worsens the probability of pregnancy in these patients.

Functional characterization of naturally-occurring constitutively activating/inactivating mutations in equine follicle-stimulating hormone receptor (eFSHR)

Objective

Follicle-stimulating hormone (FSH) is the central hormone involved in mammalian reproduction, maturation at puberty, and gamete production that mediates its function by control of follicle growth and function. The present study investigated the mutations involved in the regulation of FSH receptor (FSHR) activation.

Methods

We analyzed seven naturally-occurring mutations that were previously reported in human FSHR (hFSHR), in the context of equine FSHR (eFSHR); these include one constitutively activation variant, one allelic variant, and five inactivating variants. These mutations were introduced into wild-type eFSHR (eFSHR-wt) sequence to generate mutants that were designated as eFSHR-D566G, -A306T, -A189V, -N191I, -R572C, -A574V, and -R633H. Mutants were transfected into PathHunter EA-parental CHO-K1 cells expressing β-arrestin. The biological function of mutants was analyzed by quantitating cAMP accumulation in cells incubated with increasing concentrations of FSH.

Results

Cells expressing eFSHR-D566G exhibited an 8.6-fold increase in basal cAMP response, as compared to that in eFSHR-wt. The allelic variation mutant eFSHR-A306T was not found to affect the basal cAMP response or EC50 levels. On the other hand, eFSHR-D566G and eFSHR-A306T displayed a 1.5- and 1.4-fold increase in the maximal response, respectively. Signal transduction was found to be completely impaired in case of the inactivating mutants eFSHR-A189V, -R572C, and -A574V. When compared with eFSHR-wt, eFSHR-N191I displayed a 5.4-fold decrease in the EC50 levels (3910 ng/mL) and a 2.3-fold decrease in the maximal response. In contrast, cells expressing eFSHR-R633H displayed in a similar manner to that of the cells expressing the eFSHR-wt on signal transduction and maximal response.

Conclusion

The activating mutant eFSHR-D566G greatly enhanced the signal transduction in response to FSH, in the absence of agonist treatment. We suggest that the state of activation of the eFSHR can modulate its basal cAMP accumulation.

An in silico model using prognostic genetic factors for ovarian response in controlled ovarian stimulation: A systematic review

PURPOSE

To study the use of in silica model to better understand and propose new markers of ovarian response to controlled ovarian stimulation before IVF.

METHODS

A systematic review and in silica model using bioinformatics. After the selection of 103 papers from a systematic review process, we performed a GRADE qualification of all included papers for evidence-based quality evaluation. We included 57 genes in the silica model using a functional protein network interaction. Moreover, the construction of protein-protein interaction network was done importing these results to Cytoscape. Therefore, a cluster analysis using MCODE was done, which was exported to a plugin BINGO to determine Gene Ontology. A p value of < 0.05 was considered significant, using a Bonferroni correction test.

RESULTS

In silica model was robust, presenting an ovulation-related gene network with 87 nodes (genes) and 348 edges (interactions between the genes). Related to the network centralities, the network has a betweenness mean value = 102.54; closeness mean = 0.007; and degree mean = 8.0. Moreover, the gene with a higher betweenness was PTPN1. Genes with the higher closeness were SRD5A1 and HSD17B3, and the gene with the lowest closeness was GDF9. Finally, the gene with a higher degree value was UBB; this gene participates in the regulation of TP53 activity pathway.

CONCLUSIONS

This systematic review demonstrated that we cannot use any genetic marker before controlled ovarian stimulation for IVF. Moreover, in silica model is a useful tool for understanding and finding new markers for an IVF individualization.

PROSPERO

CRD42020197185.

Association between FSHR and ESR1 gene variants and ovarian response to gonadotropin in Egyptian women undergoing ICSI treatment

The unpredictable variability in patients' responses to gonadotropins represents one of the most intractable IVF treatment problems. Identifying the genetic variants associated with ovarian responses to gonadotropins is an important step towards developing individualised pharmacogenetics protocols for ovarian stimulation. The purpose of the current study was to evaluate correlations between FSHR rs6165, FSHR rs616, and ESR1 rs2234693 gene variants and the degree of ovarian response to gonadotropin in Egyptian women undergoing ICSI treatment. Two hundred and eighty Egyptian women (mean age of 20-35) undergoing ICSI treatment were enrolled in a cross-sectional study conducted between January 2017 and May 2019. The women were classified into three groups based on ovarian response: normal responders (retrieved oocytes = 4-15) (n = 80), poor responders (retrieved oocytes < 4) (n = 92), and high responders (retrieved oocytes> 15) (n = 108). Genomic DNA was extracted from blood samples, and PCR and DNA sequencing were performed to identify genetic variations in the different study groups. FSHR and ESR1 genetic variants were then compared in normal, poor, and high responders. DNA sequencing results showed significant differences in the frequencies of FSHR rs6166 and ESR1 rs2234693 genotypes in poor responders compared with normal responders (P ≤ 0.001 and P ≤ 0.001, respectively). In contrast, no significant differences in the frequencies of FSHR rs6166, FSHR rs6165, or ESR1 rs2234693 genotypes were observed in high responders compared with normal responders (P ≤ 0.074, P ≤ 0.353, and P ≤ 0.060, respectively). These results suggest that FSHR and ESR1 gene variants could predict the degree of ovarian response to Controlled ovarian hyperstimulation in Egyptian women.

The Role of FSHR SNPs and AMH in Follicular Fluid and Serum in Ovarian Response during COS: A Pilot Study

Background

Several studies have investigated on the polymorphism Ser680Asn of FSHR and its use as a predictive indicator of response to an IVF/ICSI protocol. Furthermore, measurement of AMH in serum and follicular fluid is a useful prognostic indicator for the outcome of an assisted reproduction attempt. The purpose of this study is to examine the FSH receptor Ser680Asn polymorphism in combination with AMH levels in both serum and follicular fluid, on the day of oocyte collection.

Materials and Methods

A total of 32 women who underwent IVF/ICSI were included. Women were grouped into 2 groups: those who received rFSH (n = 11) and those who received hMG (n = 21). Serum AMH was measured on day 3 of the cycle, and AMH in the follicular fluid on the day of oocyte retrieval; the same day peripheral blood was collected for the genotyping of Ser680Asn.

Results

No statistical significant difference was found between serum AMH and follicular fluid AMH regarding the FSH receptor genotype for the Ser680Asn polymorphism. Regarding the sAMH/ffAMH ratio in the 3 genotypes, the value was lower in Asn/Asn women than Ser/Ser and Ser/Asn, but no statistical difference was obtained. Women who carry the Ser allele have a higher number of follicles, retrieved oocytes, and mature oocytes than women who do not contain the Ser allele. Women with AMH < 2.22 ng/ml presented lower AMH follicular fluid levels and lower serum AMH/follicular fluid AMH ratio in a statistically significant manner. Concerning the genotype for the polymorphism Ser680Asn of FSHR in relation to AMH levels, no statistically significant differences were found.

Conclusions

The identification of polymorphisms, such as Ser680Asn of FSHR, along with the determination of endocrine markers in the follicular fluid, such as AMH, could lead at some point, to the personalized therapy setting per woman.

Association of single-nucleotide polymorphisms in the ESR2 and FSHR genes with poor ovarian response in infertile Jordanian women

Objective

Poor ovarian response (POR) refers to a subnormal follicular response that leads to a decrease in the quality and quantity of the eggs retrieved after ovarian stimulation during assisted reproductive treatment (ART). The present study investigated the associations of multiple variants of the estrogen receptor 2 (ESR2) and follicle-stimulating hormone receptor (FSHR) genes with POR in infertile Jordanian women undergoing ART.

Methods

Four polymorphisms, namely ESR2 rs1256049, ESR2 rs4986938, FSHR rs6165, and FSHR rs6166, were investigated in 60 infertile Jordanian women undergoing ART (the case group) and 60 age-matched fertile women (the control group), with a mean age of 33.60±6.34 years. Single-nucleotide polymorphisms (SNPs) were detected by restriction fragment length polymorphism and then validated using Sanger sequencing.

Results

The p-value of the difference between the case and control groups regarding FSHR rs6166 was very close to 0.05 (p=0.054). However, no significant differences were observed between the two groups in terms of the other three SNPs, namely ESR2 rs1256049, ESR2 rs4986938, and FSHR rs6165 (p=0.561, p=0.433, and p=0.696, respectively).

Conclusion

The association between FSHR rs6166 and POR was not statistically meaningful in the present study, but the near-significant result of this experiment suggests that statistical significance might be found in a future study with a larger number of patients.

Pharmacogenomic Biomarkers of Follicle-Stimulating Hormone Receptor Malfunction in Females with Impaired Ovarian Response-A Genetic Survey

Follicle-stimulating hormone receptor (FSHR) plays an essential role as one of the most important molecules in response to some of infertility related medications. Impaired ovarian reserve and poor response to such treatments are partially dependent on the FSHR molecule itself. However, the function and drug sensitivity for this receptor may change due to various allele and polymorphisms in the FSHR gene. Studies indicated some of the FSHR-mediated treatments utilized in clinical centers display different outcomes in specific populations, which may arise from FSHR altered genotypes in certain patients. To support the increased demands for reaching the personalized drug and hormone therapy in clinics, focusing on actionable variants through Pharmacogenomic analysis of this receptor may be necessary. The current study tries to display a perspective view on genetic assessments for Pharmacogenomic profiling of the FSHR gene via providing a systematic and critical overview on the genetics of FSHR and its diverse responses to ligands for infertility treatment in females with impaired ovarian responses and show the potential effects of the patient genetic make-up on related binding substances efficacy. All identified functional drug-related alleles were selected through a comprehensive literature search and analyzed. Advanced technologies for the genetic evaluation of them are also discussed properly.

The effects of follicle-stimulating hormone receptor (FSHR) -29 and Ser680Asn polymorphisms in IVF/ICSI

Background The aim of this study was to analyze two different polymorphisms, Ser680Asn and -29 (G>A) promoter polymorphism, of the follicle-stimulating hormone receptor (FSHR) gene, individually but also in combination, in a sample of Greek women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Materials and methods One hundred and forty-one women undergoing IVF or ICSI and 94 controls were genotyped by real-time polymerase chain reaction (RT-PCR) for the two FSHR polymorphisms. The association of the alleles with the clinical, biochemical and other parameters concerning the controlled ovarian stimulation (COS) protocol and outcome was investigated, as well as the pregnancy rate. Results The study of each polymorphism individually revealed a positive correlation of the SerSer genotype (Ser680Asn polymorphism) with higher luteinizing hormone (LH) levels on the third day of the menstrual cycle. On the other hand, the A allele for the -29 (G>A) promoter polymorphism correlated with the increased number and quality of cumulus-oocyte complexes (COCs). No differences were detected when the different genotypes of the two polymorphisms were combined - the population study was grouped according to the number of polymorphic alleles they carried (0-4 alleles). Women who presented all polymorphic alleles, AsnAsn/AA, exhibited the lowest LH levels (2.62 ± 0.68 mIU/L), but were rarely detected (n = 2, 1.4% of the studied population). Conclusions The data from this study reflect that the investigation of the combination of polymorphisms, such as FSHR -29 and Ser680Asn, could offer a valuable tool in order to evaluate and anticipate the outcome of the ovulation induction protocols, especially in the group of patients with failed attempts.

Clinical relevance of genetic variants of gonadotrophins and their receptors in controlled ovarian stimulation: a systematic review and meta-analysis

BACKGROUND

Genotype has been implicated in the outcome of ovarian stimulation. The analysis of patient-specific genotypes might lead to an individualized pharmacogenomic approach to controlled ovarian stimulation (COS). However, the validity of such an approach remains to be established.

OBJECTIVE AND RATIONALE

To define the impact of specific genotype profiles of follicle-stimulating hormone, luteinizing hormone and their receptors (FSHR, LHR and LHCGR) on ovarian stimulation outcome. Specifically, our aim was to identify polymorphisms that could be useful in clinical practice, and those that need further clinical investigation.

SEARCH METHODS

A systematic review followed by a meta-analysis was performed according to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines without time restriction. We searched the PubMed/MEDLINE, Cochrane Library, SCOPUS and EMBASE databases to identify all relevant studies published before January 2017. Only clinical trials published as full-text articles in peer-reviewed journals were included. The primary outcome was the number of oocytes retrieved.

OUTCOMES

Fifty-seven studies were assessed for eligibility, 33 of which were included in the qualitative and quantitative analyses. Data were independently extracted using quality indicators. COS outcomes related to seven polymorphisms (FSHR [rs6165], FSHR [rs6166], FSHR [rs1394205], LHB [rs1800447], LHB [rs1056917], LHCGR [rs2293275] and LHCGR [rs13405728]) were evaluated. More oocytes were retrieved from FSHR (rs6165) AA homozygotes (five studies, 677 patients, weighted mean difference [WMD]: 1.85, 95% CI: 0.85-2.85, P < 0.001; I2 = 0%) than from GG homozygotes and AG heterozygotes (four studies, 630 patients, WMD: 1.62, 95% CI: 0.28-2.95, P = 0.020; I2 = 56%). Moreover, stimulation duration was shorter in FSHR (rs6165) AA homozygotes than in AG carriers (three studies, 588 patients, WMD -0.48, 95% CI: -0.87 to -0.10, P = 0.010, I2 = 44%). A higher number of oocytes (21 studies, 2632 patients WMD: 0.84, 95% CI: 0.19 to 1.49, P = 0.01, I2 = 76%) and metaphase II oocytes (five studies, 608 patients, WMD: 1.03, 95% CI: 0.01-2.05, P = 0.050, I2 = 0%) was observed in AA than in GG homozygote carriers. FSH consumption was significantly lower in FSHR (rs1394205) GG homozygotes (three studies, 411 patients, WMD: -1294.61 IU, 95% CI: -593.08 to -1996.14 IU, P = 0.0003, I2 = 99%) and AG heterozygotes (three studies, 367 patients, WMD: -1014.36 IU, 95% CI: -364.11 to -1664.61 IU, P = 0.002, I2 = 99%) than in AA homozygotes.

WIDER IMPLICATIONS

These results support the clinical relevance of specific genotype profiles on reproductive outcome. Further studies are required to determine their application in a pharmacogenomic approach to ovarian stimulation.

Could polymorphisms of some hormonal receptor genes, involved in folliculogenesis help in predicting patient response to controlled ovarian stimulation?

PURPOSE

The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) in selected genes, responsible for hormonal regulation of folliculogenesis, are associated with response to controlled ovarian hyperstimulation (COH) and clinical characteristics of women enrolled in in vitro fertilization (IVF) programs.

METHODS

In a cross-sectional study, 60 (IVF) patients underwent COH by using gonadotropin-releasing hormone (GnRH) antagonist and recombinant follicle-stimulating hormone (rFSH) protocol. Patients were classified into three groups: poor-responders (according to Bologna criteria), normo-responders (≤ 15 oocytes), and hyper-responders (> 15 oocytes). Genotyping of SNPs AMH rs10407022, AMHR rs3741664, FSHR rs1394205 and rs6166, and ESR1 rs2234693 was performed using high-resolution melting analysis (HRMA). Basal FSH (bFSH), estradiol (E2), and anti-Müllerian hormone (AMH) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Patients with GG genotype of FSHR rs1394205 had significantly lower AMH level (P = 0.016) and required higher rFSH dose per oocyte compared to women with AA or AG genotype (P = 0.036). We also found higher frequency of GG genotype of FSHR rs1394205 in poor- (76.5%) than in hyper-responders (37.5%, P = 0.002). Patients with AA genotype of FSHR rs6166 had higher level of measured bFSH compared to those with AG or GG genotypes (P = 0.043). Women with GG genotype of AMHR rs3741664 required higher rFSH dose in comparison with patients carrying genotypes AA or AG (P = 0.028).

CONCLUSIONS

The GG genotype at position rs1394205 is associated with poor ovarian response to COH. Patients with this genotype may require higher doses of rFSH for ovulation induction.

Individualization of FSH Doses in Assisted Reproduction: Facts and Fiction

The art of ovarian stimulation for IVF/ICSI treatment using exogenous FSH should be balanced against the relative contribution of other steps of the ART process such as the IVF-lab-phase and the Embryo-Transfer. The aim of ovarian stimulation is to obtain a certain number of oocytes, that will enable the best probability of achieving a live birth. It has been suggested that more oocytes will create a better prospect for pregnancy, but studies on the question whether the retrieval of a few oocytes less or more will make the difference are not clearly supportive for this mantra. Personalization strategies have been the subject of many studies over the past 20 years. Creating the optimal response in a patient in terms of live birth prognosis as well as OHSS risks may be based on information from the Ovarian Reserve testing using the Antral Follicle Count or Anti-Mullerian Hormone, the patient's bodyweight, the ovarian response in a previous cycle, and the dosage level of FSH. Taken together, steering the ovarian response into a supposed optimal range may appear difficult as the interrelation for each of these factors with the egg number is weak. Using OR testing for choosing FSH dosage, compared to a standard normal dosage of 150 IU, has been studied in several trials. Dosage individualization, in general, does not appear to improve the prospects for live birth, but the reduction in OHSS risk may be substantial. This implies that the use of high dosages of FSH in predicted LOW responders lacks any cost-benefit for the patient and may be abandoned, while in predicted HIGH responders, reduction of the usual dosage level of 150 IU may create better safety, provided that in case of an unexpected LOW response cancelation of the cycle is refrained from. In view of recent developments in using GnRH agonist triggering of final oocyte maturation, the trend could be that with the Antagonist co-medication system and a standard dosage of 150 IU of FSH, prior ovarian reserve testing may become futile, as safety can be managed well in actual HIGH responders by replacing the high dose hCG trigger.

Pharmacogenomics in IVF: A New Era in the Concept of Personalized Medicine

Pharmacogenomics is a promising approach in the field of individualized medicine in in vitro fertilization (IVF) treatment that aims to develop optimized pharmacotherapy depending on the genetic background of each infertile woman, thus to ensure maximum effectiveness of the medication used, with minimal side effects. The unique genetic information of each infertile woman, in combination with already known, as well as new predictors of ovarian response and the progress of pharmacoepigenomics, is anticipated to greatly benefit the process of controlled ovarian stimulation. This review analyses current data on IVF pharmacogenomics, a new approach that is gradually moving to the frontline of modern IVF treatment.

Relationship Between Genotype Variants Follicle-stimulating Hormone Receptor Gene Polymorphisms (FSHR) and Morphology of Oocytes Prior to ICSI Procedures

INTRODUCTION

This study investigated association of Asn680Ser FSHR polymorphism with the ovarian response in 104 women of Albanian ethnic population enrolled in ICSI program. The reason of infertility in all cases has been identified as male factor.

METHODS

Analysis of the Asn680Ser polymorphism was performed using TaqMan^® SNP Genotyping Assay. Clinical and endocrinologic parameters were analyzed based on the genotype, age, BMI, oocyte yield, number of transferred embryos and pregnancy rate.

RESULTS

The frequencies of the Asn680 Ser genotype variants were as follows: Asn/Asn 22.1%, Asn/Ser 47.1%, and Ser/Ser 30.8%, respectively. BMI was significantly higher in the Ser/Ser group as compared to those from the Asn/Ser or the Asn/Asn group (p= 0.0010). The genotype variants Ser/Ser indicates a higher rate of oocyte retrieval (25.9%) in the immature form, metaphase I (MI) as opposed to the other two groups (Asn/Asn 23.7 % vs. Asn/Ser 21.9%), which was statistically significant (p = 0.3020).

CONCLUSIONS

FSH receptor polymorphism is associated with different ovarian response to controlled ovarian stimulation (COS), but is not an important factor in increasing the degree of pregnancy. Polymorphisms of the FSH receptor is associated with normal morphology and genetic maturation (metaphase II) oocytes in dependence of genotypic variation polymorphisms.

The carriers of the A/G-G/G allelic combination of the c.2039 A>G and c.-29 G>A FSH receptor polymorphisms retrieve the highest number of oocytes in IVF/ICSI cycles

PURPOSE

The objective of this study was the elucidation of the possible role of the single-nucleotide polymorphisms (SNP) at position -29 and 2039 of the FSH receptor gene (FSHR) as independent predictive markers of ovarian response. Indeed, the tailoring of reproductive treatments is crucial for both maximizing the success of IVF patients and obtaining a reduction in hypo- or hyper-response rates.

METHODS

This prospective, observational study analyzed the association of -29 and 2039 FSHR polymorphisms with the number of retrieved oocytes in 140 patients attending an IVF/ICSI cycle for severe male factors (≤5,000,000 spermatozoa/mL) or tubal factors at the ANDROS Day Surgery Clinic, Palermo, Italy.

RESULTS

The results of this study demonstrate that the genetic combination of A/G for polymorphism c.2039 A>G with G/G for polymorphism c.-29 G>A is significantly associated with the highest number of collected oocytes (p = 0.03). This association was significant even after controlling for the effect of other clinical variables.

CONCLUSIONS

The A/G-G/G allelic variant, identified as an independent variable, if confirmed in a larger number of patients, could be considered as a new genetic biomarker, which could increase the efficacy of prediction models for ovarian stimulation.

In Estimated Good Prognosis Patients Could Unexpected "Hyporesponse" to Controlled Ovarian Stimulation be Related to Genetic Polymorphisms of FSH Receptor?

It has been reported that 10% to 15% of young normogonadotrophic women show suboptimal response to standard gonadotropin-releasing hormone-a long protocol. These patients require higher doses of exogenous follicle-stimulating hormone (FSH). This phenomenon could be associated with genetic characteristics. In this study, FSH receptor polymorphism was retrospectively evaluated in 42 normoresponder young women undergoing an in vitro fertilization/intracytoplasmic sperm injection cycle; patients were stratified according to recombinant human FSH (r-hFSH) consumption. We selected 17 normoresponder young patients who required a cumulative dose of recombinant FSH (rFSH) >2500 UI (group A). A control group was randomly selected among patients who required a cumulative dose of rFSH <2500 UI (group B). Follicle-stimulating hormone receptor (FSH-R) 307Ala and 680Ser variants were analyzed in all our patients. Our results show that the mean number of rFSH vials (36.3 ± 7.5 vs 28.6 ± 4.5, P = .0001) and days of stimulation (12.7 ± 2.4 vs 10.8 ± 2.8, P = .03) were significantly lower in group B, whereas the number of oocytes retrieved (7.1 ± 1.5 vs 9.6 ± 2.4; P = .0005) and the average number of embryos transferred (2.1 ± 0.7 vs 2.7 ± 0.4; P = .001) were significantly lower in group A. Estradiol serum levels on the human chorionic gonadotrophin day were significantly lower in group A (997.8 ± 384.9 pg/mL vs 1749.1 ± 644.4; P = .0001). The incidence of the Ser/Ser genotype was higher in patients with higher r-hFSH consumption (group A; P = .02). Based on our results, we hypothesize an association between the FSH-R polymorphisms and a "hyporesponse" to exogenous FSH.

Effect of follicle-stimulating hormone receptor Asn680Ser polymorphism on the outcomes of controlled ovarian hyperstimulation: an updated meta-analysis of 16 cohort studies

PURPOSE

The purpose of this study is to evaluate the influence of follicle-stimulating hormone receptor (FSHR) Asn680Ser polymorphism on the ovarian response to exogenous follicle-stimulating hormone (FSH) and clinical outcomes in women undergoing controlled ovarian hyperstimulation (COH).

METHODS

A database search was conducted to identify the eligible studies that investigated the effect of FSHR Asn680Ser polymorphism on ovarian response and clinical outcomes. A pooled analysis was performed with the odds ratio (OR) or weighted mean difference (WMD) and their respective 95 % confidence interval (CI) by the STATA software with random effects model.

RESULTS

Sixteen cohort studies comprising a total of 4287 subjects were included. The number of retrieved oocytes was significantly fewer in subjects with the SS genotype at position 680, compared to subjects with the NN or NS genotype (WMD = -1.36, 95 % CI = -1.85 to -0.87). Lack of association was detected between the genotypes (SS genotype vs. NN or NS genotype) and clinical outcomes such as exogenous FSH dose (WMD = 98.96 IU, 95 % CI = -22.33 to 220.24), poor response (OR = 1.08, 95 % CI = 0.71-1.64), ovarian hyperstimulation syndrome (OHSS) (OR = 1.58, 95 % CI = 0.41-6.07), and clinical pregnancy rate (OR = 1.10, 95 % CI = 0.86-1.40). However, poor ovarian response and number of retrieved oocytes were significantly influenced by the Asn680Ser polymorphism in the Asian subjects. In addition, no publication bias was detected.

CONCLUSION

FSHR Asn680Ser polymorphism might be a significant biomarker for predicting the number of retrieved oocytes and poor response, especially in Asian subjects. Other outcomes such as exogenous FSH dose, OHSS, and pregnancy rate were not influenced by FSHR Asn680Ser polymorphism.

Follicle-stimulating hormone receptor polymorphism affects the outcome of ovulation induction in normogonadotropic (World Health Organization class 2) anovulatory subfertility

OBJECTIVE

To assess whether an FSH receptor polymorphism (Asn680Ser, rs6166) can affect the outcome of ovulation induction in normogonadotropic (World Health Organization class 2 [WHO2]) anovulatory subfertile women.

DESIGN

Prospective, longitudinal, cohort study.

SETTING

University-based fertility unit.

PATIENT(S)

A total of 240 consecutive women diagnosed with WHO2 anovulatory subfertility who underwent ovulation induction therapy. Results were replicated in a retrospective cohort of 185 patients with polycystic ovary syndrome (PCOS) (Rotterdam criteria).

INTERVENTION(S)

Ovulation induction using clomiphene citrate (CC) as first-line and exogenous gonadotropins (exFSH) as second-line therapy.

MAIN OUTCOME MEASURE(S)

Clomiphene-resistant anovulation (CRA), clomiphene failure (CCF), and ongoing pregnancy rate.

RESULT(S)

Genotyped patients (n = 159) were similar to nongenotyped women (n = 81) regarding clinical characteristics and outcomes of ovulation induction. The 680(Ser) allele was associated with CRA. A pooled analysis of both cohorts showed an 89% higher chance of CRA after CC treatment (odds ratio 1.9 [95% confidence interval 1.1-3.3]) in homozygous carriers of the FSH receptor variant (680(Ser/Ser)). A lower chance of ongoing pregnancy (hazard ratio 0.51 [95% confidence interval 0.27-0.98]) was observed among these patients during CC treatment in the prospective cohort.

CONCLUSION(S)

An FSH receptor polymorphism is associated with CRA during treatment with clomiphene citrate. These data may be used to design a treatment algorithm that is more efficacious and better tailored to the individual patient.

Pharmacogenetics of ovarian response

Effective controlled ovarian stimulation (COS) is crucial for IVF outcome. Ovarian response to follicle-stimulating hormone, however, varies widely among women undergoing ovarian stimulation. Advance identification of patients who will elicit a poor or high response to standard treatment would be of great clinical benefit for such patients. Application of pharmacogenetics to ovarian response may predict stimulation success but also help in the adjustment and design of doses prior to treatment. Different studies have examined the impact of variations in follicle-stimulating hormone receptor, biochemical pathways involved in estrogen production and action, folliculogenesis and other aspects. Recently, gene-association studies have tried to identify a number of genetic variations affecting interindividual variability in COS.

Role of the Extracellular and Intracellular Loops of Follicle-Stimulating Hormone Receptor in Its Function

Follicle-stimulating hormone receptor (FSHR) is a leucine-rich repeat containing class A G-protein coupled receptor belonging to the subfamily of glycoprotein hormone receptors (GPHRs), which includes luteinizing hormone/choriogonadotropin receptor (LH/CGR) and thyroid-stimulating hormone receptor. Its cognate ligand, follicle-stimulating hormone binds to, and activates FSHR expressed on the surface of granulosa cells of the ovary, in females, and Sertoli cells of the testis, in males, to bring about folliculogenesis and spermatogenesis, respectively. FSHR contains a large extracellular domain (ECD) consisting of leucine-rich repeats at the N-terminal end and a hinge region at the C-terminus that connects the ECD to the membrane spanning transmembrane domain (TMD). The TMD consists of seven α-helices that are connected to each other by means of three extracellular loops (ELs) and three intracellular loops (ILs) and ends in a short-cytoplasmic tail. It is well established that the ECD is the primary hormone binding domain, whereas the TMD is the signal transducing domain. However, several studies on the ELs and ILs employing site directed mutagenesis, generation of chimeric receptors and in vitro characterization of naturally occurring mutations have proven their indispensable role in FSHR function. Their role in every phase of the life cycle of the receptor like post translational modifications, cell surface trafficking, hormone binding, activation of downstream signaling, receptor phosphorylation, hormone-receptor internalization, and recycling of hormone-receptor complex have been documented. Mutations in the loops causing dysregulation of these processes lead to pathophysiological conditions. In other GPHRs as well, the loops have been convincingly shown to contribute to various aspects of receptor function. This review article attempts to summarize the extensive contributions of FSHR loops and C-terminal tail to its function.

Evaluating influence of the genotypes in the follicle-stimulating hormone receptor (FSHR) Ser680Asn (rs6166) polymorphism on poor and hyper-responders to ovarian stimulation: a meta-analysis

Background/aims

Reported associations of controlled ovarian hyperstimulation response (COH) with genotypes of the Ser680Asn (N680S) polymorphism in the follicle stimulating hormone receptor (FSHR) gene have conflicting results.

Methods

PubMed and Embase databases were searched for studies that investigated the N680S polymorphism in the FSHR gene in COH. Parameters used to examine ovarian response were poor and hyper-responses to COH. Using the meta-analytic approach, we estimated ovarian response risk (odds ratio [OR] with 95% confidence intervals) according to genotype.

Results

Our findings showed that SS genotype carriers were most likely to be poor responders (OR 1.61, p = 0.08) compared to the NN and NS genotypes which showed no associations (OR 0.93-0.95, p = 0.75-0.78). Heterogeneity of these pooled ORs warranted examining its sources. We detected outlying studies in each of the three N680S genotypes. Omitting these outliers erased the heterogeneity of the recalculated pooled outcomes. It also materially altered the SS effects where carriers became slightly unlikely to be poor responders (OR 0.90, p = 0.52). The S allele carrier effect was modulated for poor responders (OR 1.24, p = 0.39) in the Non-Hispanic Caucasian (NHC) subgroup. The likelihood of the S allele carriers (OR 1.47, p = 0.02) and the unlikelihood of the N allele carriers (OR 0.64, p = 0.007) were significant in our hyper-response findings. Confined to NHC retained significance of the S allele effects (OR 1.57, p = 0.01) but not among the N allele carriers (OR 0.68, p = 0.18).

Conclusions

In summary, this is a meta-analytical confirmation of the FSHR SS genotype role in COH response. Hyper-responder analysis strengths lie on the non-heterogeneity and robustness of its results. Non-robustness and heterogeneity of the poor-responder results compose its limitations. Thus, poor response findings probably require caution as to the interpretation as a susceptibility marker for ovarian response.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-014-0122-2) contains supplementary material, which is available to authorized users.

The luteinizing hormone beta-subunit exon 3 (Gly102Ser) gene mutation and ovarian responses to controlled ovarian hyperstimulation

BACKGROUND

Despite extensive progress in IVF techniques, one of the most difficult problems is the variability in the response to controlled ovarian hyperstimulation (COH). Recent studies show the effects of individual genetic variability on COH outcome.

OBJECTIVE

To evaluate the correlation between LHβ G1502A polymorphisms in exon 3 of the LH gene and ovarian response to COH.

MATERIALS AND METHODS

A total of 220 women treated with a long protocol for ovarian stimulation were studied. Three genotypes of GG, GA and AA were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

In total, 34 (17%) patients were poor responders, 154 (77%) were normal responders and 12 (6%) were hyper responders. The most frequent genotype was GA (55.5%) whereas 44.5% of patients showed GG genotype and there was no patient with AA genotype. In total 54.5% of normal responders, 61.8% of poor responders and 50% of hyper responders showed GA genotype.

CONCLUSION

Our results did not establish a significant relationship between this polymorphism and the ovarian response. Therefore it is still very difficult to use the genotype of patients for prediction of the ovarian response to stimulation.

Spontaneous ovarian hyperstimulation syndrome following a thawed embryo transfer cycle

This article reports a case of spontaneous ovarian hyperstimulation syndrome (OHSS) following a thawed embryo transfer cycle. OHSS, a potentially life-threatening condition, is an iatrogenic complication of controlled ovarian stimulation; therefore, it is very important to prevent and treat OHSS during treatment with ovulation-inducing agents. Despite our efforts to prevent OHSS, in this case, severe spontaneous OHSS occurred, which resulted in uncontrolled preterm labor and a preterm delivery and also persisted for 6 weeks after delivery. Freezing all embryos cannot entirely prevent the development of OHSS because OHSS can occur spontaneously. Although spontaneous OHSS remains a rare event, females with a history of OHSS may have an elevated risk for spontaneous OHSS. We suggest closely monitoring cases of pregnancy following thawed embryo transfer for early diagnosis of spontaneous OHSS and the use of conservative management.

Follicle-stimulating hormone receptor (FSHR) alternative skipping of exon 2 or 3 affects ovarian response to FSH

Genes critical for fertility are highly conserved in mammals. Interspecies DNA sequence variation, resulting in amino acid substitutions and post-transcriptional modifications, including alternative splicing, are a result of evolution and speciation. The mammalian follicle-stimulating hormone receptor (FSHR) gene encodes distinct species-specific forms by alternative splicing. Skipping of exon 2 of the human FSHR was reported in women of North American origin and correlated with low response to ovarian stimulation with exogenous follicle-stimulating hormone (FSH). To determine whether this variant correlated with low response in women of different genetic backgrounds, we performed a blinded retrospective observational study in a Turkish cohort. Ovarian response was determined as low, intermediate or high according to retrieved oocyte numbers after classifying patients in four age groups (<35, 35-37, 38-40, >40). Cumulus cells collected from 96 women undergoing IVF/ICSI following controlled ovarian hyperstimulation revealed four alternatively spliced FSHR products in seven patients (8%): exon 2 deletion in four patients; exon 3 and exons 2 + 3 deletion in one patient each, and a retention of an intron 1 fragment in one patient. In all others (92%) splicing was intact. Alternative skipping of exons 2, 3 or 2 + 3 were exclusive to low responders and was independent of the use of agonist or antagonist. Interestingly, skipping of exon 3 occurs naturally in the ovaries of domestic cats--a good comparative model for human fertility. We tested the signaling potential of human and cat variants after transfection in HEK293 cells and FSH stimulation. None of the splicing variants initiated cAMP signaling despite high FSH doses, unlike full-length proteins. These data substantiate the occurrence of FSHR exon skipping in a subgroup of low responders and suggest that species-specific regulation of FSHR splicing plays diverse roles in mammalian ovarian function.

Mechanisms in endocrinology: Genetics of FSH action: a 2014-and-beyond view

OBJECTIVE

To assess the pharmacogenetic potential of FSH for infertility treatment.

DESIGN

Review of the literature and genomic databases.

METHODS

Single-nucleotide polymorphism (SNP) assessed: rs6166 (c.2039A>G, p.N680S), rs6165 (c.919A>G, p.T307A), rs1394205 (c.-29G>A) in FSHR, and rs10835638 (c.-211G>T) in FSHB. Literature search via PubMed. Blast analysis of genomic information available in the NCBI nucleotide database. Comparison of allele frequency and haplotype distribution using the http://spsmart.cesga.estool.

RESULTS

All these SNPs appear first in Homo, result in reduced FSH action, and are present with variable frequencies and combinations worldwide. Stringent clinical studies demonstrate that the FSHR genotype influences serum FSH levels and gonadal response in both sexes. Serum FSH levels depend on the -211G>T SNP, influencing transcriptional activity of the FSHB promoter. Genotypes reducing FSH action are overrepresented in infertile subjects.

CONCLUSIONS

Although the clinical relevance of the FSHR polymorphisms alone is limited, the combination of FSHR and FSHB genotypes has a much stronger impact than either one alone in both sexes. About 20% of people are carriers of the alleles associated with lower serum FSH levels/reduced FSHR expression or activity, possibly less favorable for reproduction. Prospective studies need to investigate whether stratification of infertile patients according to their FSHR-FSHB genotypes improves clinical efficacy of FSH treatment compared with the current, naïve approach. A relative enrichment of less favorable FSHR-FSHB genotypes may be related to changes in human reproductive strategies and be a marker of some health-related advantage at the cost of reduced fertility.

Mutations and polymorphisms in FSH receptor: functional implications in human reproduction

FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.

Association between the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) rs4073366 polymorphism and ovarian hyperstimulation syndrome during controlled ovarian hyperstimulation

BACKGROUND

The aim of this study was to determine the relationship between a purported luteinizing hormone/chorionic gonadotropin (LHCGR) high function polymorphism (rs4539842/insLQ) and outcome to controlled ovarian hyperstimulation (COH).

METHODS

This was a prospective study of 172 patients undergoing COH at the Fertility and IVF Center at GWU. DNA was isolated from blood samples and a region encompassing the insLQ polymorphism was sequenced. We also investigated a polymorphism (rs4073366 G > C) that was 142 bp from insLQ. The association of the insLQ and rs4073366 alleles and outcome to COH (number of mature follicles, estradiol level on day of human chorionic gonadotropin (hCG) administration, the number of eggs retrieved and ovarian hyperstimulation syndrome (OHSS)) was determined.

RESULTS

Increasing age and higher day 3 (basal) FSH levels were significantly associated with poorer response to COH. We found that both insLQ and rs4073366 were in linkage disequilibrium (LD) and no patients were homozygous for both recessive alleles (insLQ/insLQ; C/C). The insLQ variant was not significantly associated with any of the main outcomes to COH. Carrier status for the rs4073366 C variant was associated (P = 0.033) with an increased risk (OR 2.95, 95% CI = 1.09-7.96) of developing OHSS.

CONCLUSIONS

While age and day 3 FSH levels were predictive of outcome, we found no association between insLQ and patient response to COH. Interestingly, rs4073366 C variant carrier status was associated with OHSS risk. To the best of our knowledge, this is the first report suggesting that LHCGR genetic variation might function in patient risk for OHSS.

Do estrogen receptor alpha polymorphisms have any impact on the outcome in an ART program?

PURPOSE

To investigate two of the most studied estrogen receptor alpha polymorphisms (PvuII and XbaI) in combination, in order to evaluate their impact on an ART program outcome.

METHODS

203 normally ovulating women who underwent IVF or ICSI treatment were genotyped for PvuII and XbaI polymorphisms in ESR1 intron 1 using Real-Time PCR. The relationship between the presence of polymorphic alleles and the ovulation induction parameters and outcome was examined.

RESULTS

Women were grouped according to the number of polymorphic alleles they carried in two groups (0-2 versus 3-4 polymorphic alleles). The presence of 3 or more polymorphic alleles was associated with significantly lower E2 levels on the day of hCG administration and a significantly lower rate of good quality embryos.

CONCLUSION

There is an association between ESR1 polymorphisms and some ART parameters such as the level of E2 on the day of hCG administration and the quality of the embryos. These results underline the importance of ESR1 as a candidate gene for the prediction of ovarian response to IVF/ICSI protocols. Future research work concerning several more genes is necessary for a better evaluation of patients before entering an IVF/ICSI program.

Polymorphisms in gonadotropin and gonadotropin receptor genes as markers of ovarian reserve and response in in vitro fertilization

Since gonadotropins are the fundamental hormones that control ovarian activity, genetic polymorphisms may alter gonadal responsiveness to glycoproteins; hence they are important regulators of hormone activity at the target level. The establishment of the pool of primordial follicles takes place during fetal life and is mainly under genetic control. Consequently, single nucleotide polymorphisms (SNPs) in gonadotropins and their receptors do not seem to be associated with any significant modification in the endowment of nongrowing follicles in the ovary. Indeed, the age at menopause, a biological characteristic strongly related to ovarian reserve, as well as markers of functional ovarian reserve such as anti-Müllerian hormone and antral follicle count, are not different in women with different genetic variants. Conversely, some polymorphisms in FSH receptor (FSHR) seem to be associated with modifications in ovarian activity. In particular, studies suggest that the Ser680 genotype for FSHR is a factor of relative resistance to FSH stimulation resulting in slightly higher FSH serum levels, thus leading to a prolonged duration of the menstrual cycle. Moreover, some FSHR gene polymorphisms show a positive association with ovarian response to exogenous gonadotropin administration, hence exhibiting some potential for a pharmacogenetic estimation of the FSH dosage in controlled ovarian stimulation. The study of SNPs of the FSHR gene is an interesting field of research that could provide us with new information about the way each woman responds to exogenous gonadotropin administration during ovulation induction.

The molecular basis of impaired follicle-stimulating hormone action: evidence from human mutations and mouse models

The pituitary gonadotropin follicle-stimulating hormone (FSH) interacts with its membrane-bound receptor to produce biologic effects. Traditional functions of FSH include follicular development and estradiol production in females, and the regulation of Sertoli cell action and spermatogenesis in males. Knockout mice for both the ligand (Fshb) and the receptor (Fshr) serve as models for FSH deficiency, while Fshb and Fshr transgenic mice manifest FSH excess. In addition, inactivating mutations of both human orthologs (FSHB and FSHR) have been characterized in a small number of patients, with phenotypic effects of the ligand disruption being more profound than those of its receptor. Activating human FSHR mutants have also been described in both sexes, leading to a phenotype of normal testis function (male) or spontaneous ovarian hyperstimulation syndrome (females). As determined from human and mouse models, FSH is essential for normal puberty and fertility in females, particularly for ovarian follicular development beyond the antral stage. In males, FSH is necessary for normal spermatogenesis, but there are differences in human and mouse models. The FSHB mutations in humans result in azoospermia; while FSHR mutations in humans and knockouts of both the ligand and the receptor in mice affect testicular function but do not result in absolute infertility. Available evidence also indicates that FSH may also be necessary for normal androgen synthesis in males and females.

A common Asn680Ser polymorphism in the follicle-stimulating hormone receptor gene is not associated with ovarian response to gonadotropin stimulation in patients undergoing in vitro fertilization

OBJECTIVE

To assess the role of the variant p.Asn680Ser in the follicle-stimulating hormone receptor (FSHR) gene in determining ovarian response in patients undergoing in vitro fertilization (IVF) treatment.

DESIGN

Prospective observational study.

SETTING

Tertiary referral center for reproductive medicine.

PATIENT(S)

Women (n = 421) undergoing their first cycle of controlled ovarian stimulation for IVF and 83 healthy, ethnically matched controls.

INTERVENTION(S)

Baseline pelvic ultrasound and blood tests taken on days 2 to 3 of the cycle for assessment of baseline hormones and for DNA extraction.

MAIN OUTCOME MEASURE(S)

Genotypes for FSHR p.Asn680Ser determined using TaqMan allelic discrimination assay, and ovarian response to gonadotropin treatment classified as normal, poor, or overresponse based on the number of oocytes retrieved.

RESULT(S)

The FSHR p.Asn680Ser genotype frequencies were similar in IVF patients and controls. The number of oocytes retrieved was comparable between patients with different FSHR receptor genotypes. The total amount of gonadotropin used was also similar in all the genotype groups. A logistic regression analysis showed nonstatistically significant twofold difference in the distribution of genotypes between the groups with poor and normal ovarian response.

CONCLUSION(S)

The variant FSHR p.Asn680Ser was not shown to be predictive of ovarian response, but clinically relevant differences cannot be ruled out.

LH receptor gene expression in cumulus cells in women entering an ART program

PURPOSE

Luteinizing hormone (LH) exerts its actions through its receptor (LHR), which is mainly expressed in theca cells and to a lesser extent in oocytes, granulosa and cumulus cells. The aim of the present study was the investigation of a possible correlation between LHR gene and LHR splice variants expression in cumulus cells and ovarian response as well as ART outcome.

METHODS

Forty patients undergoing ICSI treatment for male factor infertility underwent a long luteal GnRH-agonist downregulation protocol with a fixed 5-day rLH pre-treatment prior to rFSH stimulation and samples of cumulus cells were collected on the day of egg collection. RNA extraction and cDNA preparation was followed by LHR gene expression investigation through real-time PCR. Furthermore, cumulus cells were investigated for the detection of LHR splice variants using reverse transcription PCR.

RESULTS

Concerning LHR expression in cumulus cells, a statistically significant negative association was observed with the duration of ovarian stimulation (odds ratio = 0.23, p = 0.012). Interestingly, 6 over 7 women who fell pregnant expressed at least two specific types of LHR splice variants (735 bp, 621 bp), while only 1 out of 19 women that did not express any splice variant achieved a pregnancy.

CONCLUSIONS

Consequently, the present study provide a step towards a new role of LHR gene expression profiling as a biomarker in the prediction of ovarian response at least in terms of duration of stimulation and also a tentative role of LHR splice variants expression in the prediction of pregnancy success.

Effects of polymorphisms in gonadotropin and gonadotropin receptor genes on reproductive function

Gonadotropins, the action of which is mediated at the level of their gonadal receptors, play a key role in sexual development, reproductive functions and in metabolism. The involvement of the gonadotropins and their receptor genotypes on reproductive function are widely studied. A large number of gonadotropins and their receptors gene polymorphisms are known, but the only one considerable as a clear, absolute genetic marker of reproductive features or disfunctions is the FSHR Asn680Ser polymorphism, since it modulates ovarian response to FSH. The aim of these studies would to be the prediction of the genetic causes of sex-related diseases to enable a customized clinical setting based on individual response of patients undergoing gonadotropin stimulation. In this review we discuss the latest information about the effects of polymorphisms of the gonadotropins and their receptor genes on reproductive functions of both male and female, and discuss their patho-physiological implications.

Genetic variants and environmental factors associated with hormonal markers of ovarian reserve in Caucasian and African American women

BACKGROUND

The ovarian reserve (number and quality of oocytes) is correlated with reproductive potential as well as somatic health, and is likely to have multiple genetic and environmental determinants. Several reproductive hormones are closely linked with the oocyte pool and thus can serve as surrogate markers of ovarian reserve. However, we know little about the underlying genes or genetic variants.

METHODS

We analyzed genetic variants across the genome associated with two hormonal markers of ovarian reserve, FSH and anti-Mullerian hormone, in a reproductively normal population of Caucasian (n = 232) and African American (n = 200) women, aged 25–45 years. We also examined the effects of environmental or lifestyle factors on ovarian reserve phenotypes.

RESULTS

We identified one variant approaching genome-wide significance (rs6543833; P= 8.07 × 10⁻⁸) and several nominal variants nearby and within the myeloid-associated differentiation marker-like (MYADML) gene, that were associated with FSH levels in African American women; these were validated in Caucasian women. We also discovered effects of smoking and oral contraceptive use on ovarian reserve phenotypes, with alterations in several reproductive hormones.

CONCLUSIONS

This work is the largest study on ovarian reserve in women of reproductive age and is the only genome-wide study on ovarian reserve markers. The genes containing or near the identified variants have no known roles in ovarian biology and represent interesting candidate genes for future investigations. The discovery of genetic markers may lead to better long-range predictions of declining ovarian function, with implications for reproductive and somatic health.