Single-nucleotide polymorphisms in the FSH receptor gene and ovarian performance: future role in IVF

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.

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.

Advances in the Regulation of Mammalian Follicle-Stimulating Hormone Secretion

Simple Summary

The reproduction of mammals is regulated by the hypothalamic-pituitary-gonadal axis. Follicle stimulating hormone, as one of the gonadotropins secreted by the pituitary gland, plays an immeasurable role. This article mainly reviews the molecular basis and classical signaling pathways that regulate the synthesis and secretion of follicle stimulating hormone, and summarizes its internal molecular mechanism, which provides a certain theoretical basis for the research of mammalian reproduction regulation and the application of follicle stimulating hormone in production practice.

Abstract

Mammalian reproduction is mainly driven and regulated by the hypothalamic-pituitary-gonadal (HPG) axis. Follicle-stimulating hormone (FSH), which is synthesized and secreted by the anterior pituitary gland, is a key regulator that ultimately affects animal fertility. As a dimeric glycoprotein hormone, the biological specificity of FSH is mainly determined by the β subunit. As research techniques are being continuously innovated, studies are exploring the underlying molecular mechanism regulating the secretion of mammalian FSH. This article will review the current knowledge on the molecular mechanisms and signaling pathways systematically regulating FSH synthesis and will present the latest hypothesis about the nuclear cross-talk among the various endocrine-induced pathways for transcriptional regulation of the FSH β subunit. This article will provide novel ideas and potential targets for the improved use of FSH in livestock breeding and therapeutic development.

The relationship between FSH receptor polymorphism status and IVF cycle outcome: a retrospective observational study

RESEARCH QUESTION

What is the association between FSH receptor (FSHR) gene polymorphism at position 680 and live birth in women undergoing IVF and intracytoplasmic sperm injection (ICSI).

DESIGN

In this retrospective cohort study, data were collected from the Electronic Patient Database of the VU University Medical Centre, Amsterdam, The Netherlands. Women undergoing their first IVF/ICSI cycle between January 2008 and March 2012, of whom the FSHR genotype was determined, were included. The main outcome was live birth rate. Secondary outcomes were ongoing pregnancy, total number of follicles, oocytes and embryos.

RESULTS

The FSHR genotype distribution was as follows: 334 women in the Asn/Asn group (28.2%), 617 in the Asn/Ser group (52.1%) and 234 in the Ser/Ser group (19.7%). Basal FSH concentration was highest in the Ser/Ser group (P = 0.006). The number of oocytes (P = 0.01) and number of embryos (P = 0.02) were lowest in the Ser/Ser group. The Asn/Asn group showed a significantly lower live birth rate. Live birth rates were 21.9% versus 31.1% and 27.6% (P = 0.009), for Asn/Asn, Asn/Ser and Ser/Ser, respectively. Logistic regression analysis, however, showed no significant difference on cumulative live birth rate between the three genotypes either unadjusted or when adjusted for age.

CONCLUSION

The homozygous Ser/Ser genotype of FSHR polymorphism at position 680 is associated with a reduced ovarian response to ovarian stimulation in IVF/ICSI. No difference in cumulative live birth rate was found.

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.

Understanding Ovarian Hypo-Response to Exogenous Gonadotropin in Ovarian Stimulation and Its New Proposed Marker-The Follicle-To-Oocyte (FOI) Index

Hypo-responsiveness to controlled ovarian stimulation is an undervalued topic in reproductive medicine. This phenomenon manifests as a low follicles output rate (FORT) with a discrepancy between the relatively low number of pre-ovulatory follicles which develop following ovarian stimulation as compared to the number of antral follicles available at the start of stimulation. The pathophysiology mechanisms explaining the ovarian resistance to gonadotropin stimulation are not fully understood, but the fact that both hypo-responders and normal responders share similar phenotypic characteristics suggests a genotype-based mechanism. Indeed, existing evidence supports the association between specific gonadotropin and their receptor polymorphisms and ovarian hypo-response. Apart from genotypic trait, environmental contaminants and oxidative stress might also be involved in the hypo-response pathogenesis. The ratio between the number of oocytes collected at the ovum pick up and the number of antral follicles at the beginning of OS [Follicle to oocyte index (FOI)] is proposed as a novel parameter to assess the hypo-response. Compared with traditional ovarian reserve markers, FOI might reflect most optimally the dynamic nature of follicular growth in response to exogenous gonadotropin. In this review, we contextualize the role of FOI as a parameter to identify this condition, discuss the underlying mechanisms potentially implicated in the pathogenesis of hypo-response, and appraise possible the treatment strategies to overcome hyper-responsiveness to gonadotropin stimulation.

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.

AMH type II receptor and AMH gene polymorphisms are not associated with ovarian reserve, response, or outcomes in ovarian stimulation

Purpose

Genetic variation may influence women’s response to ovarian stimulation therapy. The purpose of this study was to investigate any effects of genetic variants in the anti-Müllerian hormone (AMH) and AMH type II receptor genes on ovarian response/treatment outcomes and on current markers of ovarian reserve in individuals undergoing in vitro fertilisation (IVF) treatment.

Methods

In this prospective observational study, we genotyped the AMH c.146G>T, p.(Ile49Ser) and AMHR2 -482A>G variants in 603 unrelated women undergoing their first cycle of controlled ovarian stimulation for IVF and ICSI (intracytoplasmic sperm injection) using gonadotrophins at a tertiary referral centre for reproductive medicine. Pelvic ultrasound and blood hormone levels were taken on days 2–3 of the cycle. Genotypes were determined using TaqMan allelic discrimination assay. Regression analysis was performed to assess the relationship between the genotypes and the ovarian reserve markers (FSH, AMH, antral follicle count) and the early outcomes of response (number of oocytes retrieved and gonadotropin dose) as well as the treatment outcome (live birth).

Results

There were no significant associations between the variants AMH c.146G>T and AMHR2 -482A>G with ovarian response in terms of number of oocytes retrieved (p = 0.08 and p = 0.64, respectively), live births (p = 0.28 and p = 0.52) and/or markers of ovarian reserve.

Conclusions

Genotyping of the AMH c.146G>T and AMHR2 -482A>G polymorphisms does not provide additional useful information as a predictor of ovarian reserve or ovarian response and treatment outcomes.

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.

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.

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.

Association of follicle-stimulating hormone receptor polymorphisms with ovarian response in Chinese women: a prospective clinical study

BACKGROUND

Follicular stimulating hormone (FSH) is a glycoprotein and widely used for the treatment of infertility; FSH action is mediated by FSH receptor (FSHR), SNPs of which determine the ovarian response. Two polymorphisms of the FSHR gene were identified, which caused a change of threonine (T) to alanine (A) at position 307 and asparagine (N) to serine(S) at position 680. Both polymorphic sites give rise to three discrete variants of the FSHR: TT, TA, and AA for position 307; NN, NS, and SS for position 680.

METHODOLOGY/PRINCIPAL FINDINGS

450 Chinese women were recruited in an assisted reproductive technology program from October 2011 to March 2012. FSHR polymorphisms at the positions 307 and 680 were examined by PCR-RFLP. Serum FSH and estradiol level, FSH amount, ovarian response and pregnancy rate were recorded during treatment. The basal FSH levels were higher in AA [7.38 ± 2.07 vs 6.34 ± 1.75, 6.63 ± 1.94, P<0.05, 95% CI (6.75, 8.01)] and SS [7.51 ± 2.01 vs 6.31 ± 1.75, 6.66 ± 1.96, P<0.05, 95% CI (6.88, 8.15)] compared to other genotypes respectively; the days for ovulation induction was slightly longer in AA and SS. Women with AA and SS have higher rates of poor response compared to carriers of other genotypes (P<0.05). Furthermore, there is a nearly complete linkage between these two polymorphisms in Chinese women (D'=0.95, r(2)=0.84).

CONCLUSIONS/SIGNIFICANCE

In Chinese women receiving ART, the subjects with AA and SS genotypes have higher basal FSH levels, and these genotypes are associated with an increased risk of poor response. Our data suggested that the personalized FSH therapy may be applied according to patient's genetic background in clinical settings. The linkage suggested that the polymorphisms of Thr307Ala and Asn680Ser may be used as TAG-SNP markers for analysis of potential genotyping in ART.

PCOS and peripheral AMH levels in relation to FSH receptor gene single nucleotide polymorphisms

OBJECTIVES

To determine if an association exists between the follicle-stimulating hormone receptor (FSHR) gene p.Asn680Ser polymorphism and polycystic ovary syndrome (PCOS) or with high anti-mullerian hormone (AMH) levels without PCOS.

PATIENTS

Fifty-eight women with PCOS, 24 women with high AMH (>44.5 pmol/L) without PCOS and 80 healthy ethnically matched female controls.

MAIN OUTCOME MEASURES

Prevalence of the FSHR p.Asn680Ser polymorphism, baseline serum AMH levels and response to ovulation induction with clomiphene citrate.

RESULTS

The frequency of FSHR p.Asn680Ser genotypes were not significantly different between PCOS patients, patients with high AMH without PCOS and controls (p = 0.88). Of the women with PCOS, 34/58 were on clomiphene citrate treatment and 12/34 were resistant. There was no association between sensitivity or resistance to clomiphene and p.Asn680Ser genotypes (p = 0.38).

CONCLUSIONS

There is no evidence that FSHR p.Asn680Ser genotypes are associated with PCOS, high AMH levels or response to clomiphene citrate.

Hormonal, functional and genetic biomarkers in controlled ovarian stimulation: tools for matching patients and protocols

Variability in the subfertile patient population excludes the possibility of a single approach to controlled ovarian stimulation (COS) covering all the requirements of a patient. Modern technology has led to the development of new drugs, treatment options and quantitative methods that can identify single patient characteristics. These could potentially be used to match patients with the right treatment options to optimise efficacy, safety and tolerability during COS. Currently, age and follicle-stimulating hormone (FSH) level remain the most commonly used single patient characteristics in clinical practice. These variables only provide a basic prognosis for success and indications for standard COS treatment based on gross patient categorisation. In contrast, the anti-Müllerian hormone level appears to be an accurate predictor of ovarian reserve and response to COS, and could be used successfully to guide COS. The antral follicle count is a functional biomarker that could be useful in determining the dose of FSH necessary during stimulation and the success of treatment. Finally, in the future, genetic screening may allow an individual patient's response to stimulation during COS to be predicted based on genotype. Unfortunately, despite the predictive power of these measures, no single biomarker can stand alone as a guide to determine the best treatment option. In the future, hormonal, functional and genetic biomarkers will be used together to personalise COS.

FSH-receptor Ala307Thr polymorphism is associated to polycystic ovary syndrome and to a higher responsiveness to exogenous FSH in Italian women

OBJECTIVE

Herein we analyzed FSH-R polymorphism at position 307 aiming (a) to assess the prevalence of the three allelic variants (Ala307Ala, Ala307Thr and Thr307Thr) in relation to the type of ovary and (b) to clarify if the allelic variant could influence the responsiveness to exogenous FSH.

STUDY DESIGN

We prospectively studied a group of 106 Italian women undergoing in vitro fertilization (IVF), among which 40 were subjects with polycystic ovary syndrome (PCOS) and 66 were normo-ovulatory women with a normal ovarian morphology at transvaginal ultrasound. DNA extraction, denaturing high-performance liquid chromatography (dHPLC) and DNA sequencing were used to detect the FSH-R 307 polymorphic genotype and the whole exon 10 was analyzed.

RESULTS

The heterozygote variant Ala307Thr was significantly more frequent than the homozygote variants in women with PCOS, whereas in normo-ovulatory women with normal ovary the three allelic variants had a comparable prevalence. Women bearing the Ala307Thr variant showed a higher ovarian responsiveness to exogenous FSH than normo-ovulatory subjects.

CONCLUSIONS

The heterozygote FSH-R polymorphism Ala307Thr is significantly more frequent in women with PCOS than in normo-ovulatory subjects and is more frequently associated with a higher ovarian responsiveness to exogenous FSH.

Individualised controlled ovarian stimulation (iCOS): maximising success rates for assisted reproductive technology patients

BACKGROUND

In the last two decades, pregnancy rates for patients undergoing in-vitro fertilisation (IVF) have significantly increased. Some of the major advances responsible for this improvement were the introduction of controlled ovarian stimulation (COS) for the induction of multiple follicle development, and the utilisation of mid-luteal gonadotropin-releasing hormone agonists to achieve pituitary down-regulation and full control of the cycle. As a result, a combination of a gonadotropin-releasing hormone agonist with high doses (150-450 IU/day) of recombinant follicle-stimulating hormone has become the current standard approach for ovarian stimulation. However, given the heterogeneity of patients embarking on IVF, and the fact that many different drugs can be used alone or in different combinations (generating multiple potential protocols of controlled ovarian stimulation), we consider the need to identify special populations of patients and adapt treatment protocols accordingly, and to implement a more individualised approach to COS.

DISCUSSION

Studies on mild, minimal and natural IVF cycles have yielded promising results, but have focused on fresh embryo transfers and included relatively young patient populations who generally have the potential for more favourable outcomes. The efficacy of these protocols in patients with a poorer prognosis remains to be tested. When comparing protocols for COS, it is important to think beyond current primary endpoints, and to consider the ideal quality and quantity of oocytes and embryos being produced per stimulated patient, in order to achieve a pregnancy. We should also focus on the cumulative pregnancy rate, which is based on outcomes from fresh and frozen embryos from the same cycle of stimulation. Individualised COS (iCOS) determined by the use of biomarkers to test ovarian reserve has the potential to optimise outcomes and reduce safety issues by adapting treatment protocols according to each patient's specific characteristics. As new objective endocrine, paracrine, functional and/or genetic biomarkers of response are developed, iCOS can be refined further still, and this will be a significant step towards a personalised approach for IVF.

CONCLUSIONS

A variety of COS protocols have been adopted, with mixed success, but no single approach is appropriate for all patients within a given population. We suggest that treatment protocols should be adapted for individual patients through iCOS; this approach promises to be one of the first steps towards implementing personalised medicine in reproductive science.