Improved responsiveness of PCOS patients to clomiphene after CYP17a inhibitor

The comparative effectiveness of 55 interventions in obese patients with polycystic ovary syndrome: A network meta-analysis of 101 randomized trials

BACKGROUND

Polycystic ovary syndrome (PCOS) affects up to 18% of reproductive-age females. The prevalence of obesity in PCOS patients reaches up to 80%, which is 2-fold higher than the general population.

OBJECTIVE

The present study aimed to compare the effectiveness of 55 pharmacological interventions across 17 different outcomes in overweight/obese PCOS patients with hyperandrogenism manifestations for both short- and long-term follow-ups. A comprehensive literature search was performed on PubMed, Scopus, Embase, Science Direct, Web of Science, and Cochrane CENTRAL for randomized controlled trials comparing any conventional pharmacological intervention as a monotherapy or a combination in overweight/obese patients with polycystic ovary syndrome and hyperandrogenism manifestations. Extracted data included three main parameters; I. Anthropometric parameters (BMI, Waist and Hip circumferences, and Waist/HIP ratio), II. Hormonal parameters (FSH, LH, FSG, SHBG, Estradiol, Total Testosterone, Free testosterone, DHEAS, Androstenedione), and III. Metabolic parameters (Total Cholesterol, LDL-C, HDL-C, Triglycerides, Fasting glucose, Fasting glucose, HOMA-IR). Critical appraisal and risk of bias assessments were performed using the modified Jadad scale, and the overall quality of this network meta-analysis was evaluated according to the CINeMA framework. We performed both a pairwise meta-analysis and a network meta-analysis to evaluate the effect sizes with 95% CI, and we calculated the surface under the cumulative ranking curve (SUCRA) for each intervention.

RESULTS

Our final search on May 15th 2021 retrieved 23,305 unique citations from searching six electronic databases. Eventually, 101 RCTs of 108 reports with a total of 8,765 patients were included in our systematic review and multi-treatments meta-analysis. 55 different interventions were included: 22 monotherapies, and 33 combinations. The two-dimensional cluster ranking of the average SUCRA values for metabolic and hormonal parameters with significant estimates revealed flutamide (77.5%, 70%; respectively) as the highest and rosiglitazone (38.2%, 26.3%; respectively) as the lowest, in terms of the overall efficacy in reducing weight and hyperandrogenism. However, cyproterone-acetate+ethinylestradiol exhibited a higher ranking in improving hormonal parameters (71.1%), but even a lower-ranking regarding metabolic parameters (34.5%).

CONCLUSIONS AND RELEVANCE

Current evidence demonstrated the superiority of flutamide in improving both metabolic and hormonal parameters, and the higher efficacy of cyproterone-acetate+ethinylestradiol only in improving hormonal parameters. Nearly all interventions were comparable in female hormones, FGS, HDL, glucose, and insulin levels improvements.

Clomiphene and other antioestrogens for ovulation induction in polycystic ovarian syndrome

BACKGROUND

Subfertility due to anovulation is a common problem in women. First-line oral treatment is with antioestrogens such as clomiphene citrate, but resistance may be apparent with clomiphene. Alternative and adjunctive treatments have been used including tamoxifen, dexamethasone, and bromocriptine. The effectiveness of these is to be determined.

OBJECTIVES

To determine the relative effectiveness of antioestrogen agents including clomiphene alone or in combination with other medical therapies in women with subfertility associated with anovulation, possibly caused by polycystic ovarian syndrome.

SEARCH METHODS

We conducted a search of the Cochrane Gynaecology and Fertility Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, and CINAHL (all from inception to August 2016) to identify relevant randomised controlled trials (RCTs). We searched the United Kingdom National Institute for Clinical Excellence (NICE) guidelines and the references of relevant reviews and RCTs. We also searched the clinical trial registries for ongoing trials (inception until August 2016).

SELECTION CRITERIA

We considered RCTs comparing oral antioestrogen agents for ovulation induction (alone or in conjunction with medical therapies) in anovulatory subfertility. We excluded insulin-sensitising agents, aromatase inhibitors, and hyperprolactinaemic infertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment. The primary outcome was live birth; secondary outcomes were pregnancy, ovulation, miscarriage, multiple pregnancy, ovarian hyperstimulation syndrome, and adverse effects.

MAIN RESULTS

This is a substantive update of a previous review. We identified an additional 13 studies in the 2016 update. The review now includes 28 RCTs (3377 women) and five RCTs awaiting classification. Five of the 28 included trials reported live birth/ongoing pregnancy. Secondary outcomes were poorly reported.The quality of the evidence ranged from low to very low. The primary reasons for downgrading the evidence were imprecision and risk of bias associated with poor reporting. Antioestrogen versus placebo Live birth rate, miscarriage rate, multiple pregnancy rate, and ovarian hyperstimulation syndrome (OHSS)No data were reported for these outcomes. Clinical pregnancy rateClomiphene citrate was associated with an increased chance of a clinical pregnancy compared with placebo, though the size of the benefit was very uncertain (odds ratio (OR) 5.91, 95% confidence interval (CI) 1.77 to 19.68; 3 studies; 133 women; low-quality evidence). If the chance of a clinical pregnancy was 5% in the placebo group, then between 8% and 50% of women would have a clinical pregnancy in the clomiphene group. Clomiphene citrate versus tamoxifen Live birth rateThere was no clear evidence of a difference in the chance of a live birth between the clomiphene citrate and tamoxifen groups (OR 1.24, 95% CI 0.59 to 2.62; 2 studies; 195 women; low-quality evidence). If 20% of women in the tamoxifen group had a live birth, then between 13% and 40% of women in the clomiphene citrate group would have a live birth. Miscarriage rateThere was no clear evidence of a difference in the chance of a miscarriage between the clomiphene citrate and tamoxifen groups (OR 1.81, 95% CI 0.80 to 4.12; 4 studies; 653 women; low-quality evidence). If 3% of women in the tamoxifen group had a miscarriage, then between 2% and 10% in the clomiphene citrate group would have a miscarriage. Clinical pregnancy rateThere was no clear evidence of a difference in the chance of a clinical pregnancy between the clomiphene citrate and tamoxifen groups (OR 1.30, 95% CI 0.92 to 1.85; 5 studies; 757 women; I² = 69%; low-quality evidence). If 22% of women in the tamoxifen group had a clinical pregnancy, then between 21% and 35% in the clomiphene citrate group would have a clinical pregnancy. Multiple pregnancy rate There was insufficient evidence of a difference in the chance of a multiple pregnancy between the clomiphene citrate group (OR 2.34, 95% CI 0.34 to 16.04; 3 studies; 567 women; very low-quality evidence). If 0% of women in the tamoxifen group had a multiple pregnancy, then between 0% and 0.5% of women in the clomiphene group would have a multiple pregnancy. OHSSThere were no instances of OHSS in either the clomiphene citrate or the tamoxifen group reported from three studies. Clomiphene citrate with tamoxifen versus tamoxifen alone Clinical pregnancy rateThere was insufficient evidence to determine whether there was a difference between groups (OR 3.32, 95% CI 0.12 to 91.60; 1 study; 20 women; very low-quality evidence). No data were reported for the other outcomes. Other comparisons of interestLimited evidence suggested that compared with a gonadotropin, clomiphene citrate was associated with a reduced chance of a pregnancy, ongoing pregnancy, or live birth, with no clear evidence of a difference in multiple pregnancy rates.The comparison of clomiphene citrate plus medical adjunct versus clomiphene alone was limited by the number of trials reporting the comparison and poor reporting of clinical outcomes relevant to this systematic review and by the number of adjuncts reported (ketoconazole, bromocriptine, dexamethasone, combined oral contraceptive, human chorionic gonadotropin, hormone supplementation). The addition of dexamethasone or combined oral contraceptive suggested a possible benefit in pregnancy outcomes, but findings were very uncertain and further research is required to confirm this.There was limited evidence suggesting that a 10-day regimen of clomiphene citrate improves pregnancy outcomes compared with a 5-day regimen. Data for early versus late regimens of clomiphene citrate were insufficient to be able to make a judgement on differences for pregnancy outcomes.

AUTHORS' CONCLUSIONS

We found evidence suggesting that clomiphene citrate improves the chance of a clinical pregnancy compared with placebo, but may reduce the chance of live birth or ongoing pregnancy when compared with a gonadotropin. Due to low event rates, we advise caution interpreting these data.The comparison of clomiphene citrate plus medical adjunctive versus clomiphene alone was limited by the number of trials reporting the comparison. The evidence was very low quality and no firm conclusions could be drawn, but very limited evidence suggested a benefit from adjunctive dexamethasone or combined oral contraceptives. Low-quality evidence suggested that a 10-day regimen of clomiphene citrate improves pregnancy rates compared with a 5-day regimen, but further research is required.

Ketoconazole inhibits ovulation as a result of arrest of follicular steroidogenesis in the rat ovary

OBJECTIVE

Ketoconazole (KCZ) is a known inhibitor of steroidogenic P450 enzymes in the adrenal cortex and the gonads. Previous studies examined the potential clinical use of KCZ for attenuation of ovarian response to gonadotropin treatments. This study aimed to use the superovuating rat model to explore the effect of KCZ on ovarian steroidogenesis, follicular function, and development toward ovulation.

METHODS

Prepubertal rats were treated with equine chorionic gonadotropin (eCG)/human CG (hCG) resulting in multiple follicular development and ovulation. The effect of KCZ on this model was examined by administration of KCZ-gel formula and subsequent analyses of ovarian steroidogenesis, rate of ovulation, morphometric assessments of follicular parameters, and cell-specific steroidogenic maturation of the treated ovaries.

RESULTS

When applied shortly before gonadotropin stimulation, KCZ markedly reduced ovarian progesterone, androstenedione, and estradiol levels down to 18.7, 36.5, and 19.0%, respectively (P < 0.001). A single KCZ-gel administration of 6, 12, and 24 mg/rat resulted in reduction of ovulated ova/ovary down to 8.6 ± 4.9, 5.1 ± 4.3, and 2.4 ± 3.2, respectively, as compared to 13.6 ± 4.4 ova found in the oviduct of control-gel-injected animals (P < 0.001). An alternative protocol made use of small KCZ doses injected in non-gel formula (5 mg/dose/8 hours), commenced with the eCG administration and terminated 24 hours later; this treatment readily inhibited the ovulation rates to 6.6 ± 6.6 as compared to 16.5 ± 4.1 ova/ovary in the control group (P < 0.01). By contrast, KCZ failed to inhibit ovulation if administered 24 hours after eCG injection. Anovulation by KCZ resulted from arrest of follicular development at the stage of 800–840 μm Graafian follicles as compared to 920 μm of peri-ovulatory follicles (OFs) observed in the control group, P = 0.029. In addition, absence of CYP11A1 expression was evident in the granulosa cell layers of the growth-arrested follicles, which also lacked mucified mature cumulus cell complexes.

CONCLUSION

These results suggest that KCZ-mediated inhibition of follicular maturation probably results from impaired steroidogenesis at early phase of follicular development toward ovulation. Hence, attenuation of folliculogenesis by KCZ may be harnessed to modulate gonadotropin-ovarian stimulation in fertility treatments.

Selective inhibition of steroidogenic enzymes by ketoconazole in rat ovary cells

OBJECTIVE

Ketoconazole (KCZ) is an anti-fungal agent extensively used for clinical applications related to its inhibitory effects on adrenal and testicular steroidogenesis. Much less information is available on the effects of KCZ on synthesis of steroid hormones in the ovary. The present study aimed to characterize the in situ effects of KCZ on steroidogenic enzymes in primary rat ovary cells.

METHODS

Following the induction of folliculogenesis in gonadotropin treated rats, freshly prepared ovarian cells were incubated in suspension for up to four hours while radiolabeled steroid substrates were added and time dependent generation of their metabolic products was analyzed by thin layer chromatography (TLC).

RESULTS

KCZ inhibits the P450 steroidogenic enzymes in a selective and dose dependent manner, including cholesterol side-chain cleavage cytochrome P450 (CYP11A1/P450scc), the 17α-hydroxylase activity of CYP17A1/P450c17, and CYP19A1/P450arom, with IC₅₀ values of 0.3, 1.8, and 0.3 μg/mL (0.56, 3.36, and 0.56 μM), respectively. Unaffected by KCZ, at 10 μg/mL, were the 17,20 lyase activity of CYP17A1, as well as five non-cytochrome steroidogenic enzymes including 3β-hydroxysteroid dehydrogenase-Δ^5–4 isomerase type 1 (3βHSD1), 5α-reductase, 20α-hydroxysteroid dehydrogenase (20α-HSD), 3α-hydroxysteroid dehydrogenase (3α-HSD), and 17β-hydroxysteroid dehydrogenase type 1 (17HSD1).

CONCLUSION

These findings map the effects of KCZ on the ovarian pathways of progestin, androgen, and estrogen synthesis. Hence, the drug may have a potential use as an acute and reversible modulator of ovarian steroidogenesis in pathological circumstances.

Clomiphene and anti-oestrogens for ovulation induction in PCOS

BACKGROUND

Subfertility due to anovulation is a common problem in women. First-line oral treatment is with anti-oestrogens, for example clomiphene citrate, but resistance (failure to ovulate) may be apparent with clomiphene. Alternative and adjunctive treatments have been developed such as tamoxifen, dexamethasone, and bromocriptine.

OBJECTIVES

To determine the relative effectiveness of anti-oestrogen agents alone or in combination with other medical therapies in women with subfertility associated with anovulation, possibly caused by polycystic ovarian syndrome (PCOS).

SEARCH STRATEGY

A search was conducted using the Cochrane Menstrual Disorders and Subfertility Group Trials Register (May 2009), CENTRAL (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to May 2009), and EMBASE (1980 to May 2009) for identification of relevant randomised controlled trials (RCTs). The United Kingdom National Institute for Clinical Excellence (NICE) guidelines and the references of relevant reviews and RCTs were searched.

SELECTION CRITERIA

RCTs comparing oral anti-oestrogen agents for ovulation induction (alone or in conjunction with medical therapies) in anovulatory subfertility were considered. Insulin sensitising agents, aromatase inhibitors, and hyperprolactinaemic infertility were excluded.

DATA COLLECTION AND ANALYSIS

Data extraction and quality assessment were done independently by two review authors. The primary outcome was live birth; secondary outcomes were pregnancy, ovulation, miscarriage, multiple pregnancy, overstimulation, ovarian hyperstimulation syndrome, and women reported adverse effects.

MAIN RESULTS

This is a substantive update of a previous review. Fifteen RCTs were included. One trial reported live birth. Miscarriage, multiple pregnancy rates and adverse events were poorly reported.Clomiphene was effective in increasing pregnancy rate compared to placebo (OR 5.8, 95% CI 1.6 to 21.5) as was clomiphene plus dexamethasone treatment (OR 9.46, 95% CI 5.1 to 17.7) compared to clomiphene alone. No evidence of a difference in effect was found between clomiphene versus tamoxifen or clomiphene in conjunction with human chorionic gonadotrophin (hCG) versus clomiphene alone.The remaining results had only one study in each comparison. A significant improvement in the pregnancy rate was reported for clomiphene plus combined oral contraceptives versus clomiphene alone. No evidence of a difference in effect on pregnancy rate was found with any of the other comparisons.

AUTHORS' CONCLUSIONS

This review shows evidence supporting the effectiveness of clomiphene citrate and clomiphene in combination with dexamethasone for pregnancy rate only. There is limited evidence on the effects of these drugs on outcomes such as miscarriage. Evidence in favour of these interventions is flawed due to the lack of evidence on live births.

Polycystic ovarian syndrome--prognosis and outcomes

Polycystic ovarian syndrome (PCOS) is a condition that is present in 5-6% of women of reproductive age. It has potentially profound implications for women with regard to anovulatory infertility and symptoms related to elevated androgen levels. In addition, in later life women are prone to significant health problems related to hyperinsulinaemia, with an excess risk for diabetes and cardiovascular risk factors. Evidence suggests that the adverse features of PCOS can be ameliorated with lifestyle intervention, such as diet and exercise, while further short-term benefits related to ovulation and cardiac risk factors may be derived from medication with metformin. Evidence for the long-term use of metformin to protect against adverse cardiovascular outcomes and for the use of metformin throughout pregnancy to reduce the risk of miscarriage, gestational diabetes, pre-eclampsia and fetal macrosomia is still lacking.

Irregular cycles and steroid hormones in polycystic ovary syndrome

BACKGROUND

This cross-sectional study was undertaken to evaluate the factors that relate to menstrual status (oligo-amenorrhoea versus eumenorrhoea) in polycystic ovary syndrome (PCOS).

METHODS

A total of 234 women with clinical and biochemical features suggestive of PCOS underwent metabolic and hormonal evaluation. A forward stepwise logistic regression model was created based on the results to determine variables related to ovulatory status.

RESULTS

Only follicular phase progesterone and estradiol (E(2)) were retained in the final model. This model correctly classified 80% of PCOS women by ovulatory status. Univariate analysis revealed no difference in progesterone between ovulatory groups but E(2) was higher in anovulatory groups. This suggested interaction between progesterone and E(2) and the single interaction variable (progesterone/E(2)) also classified 80% of women by ovulatory status correctly.

CONCLUSION

The results suggest that a low ratio of progesterone to E(2) is associated with menstrual irregularity and ovulatory status in PCOS.

Oral anti-oestrogens and medical adjuncts for subfertility associated with anovulation

BACKGROUND

Infertility due to anovulation is a common problem in women. The first line oral treatment is with anti-oestrogens, such as clomiphene citrate. Unfortunately there may be resistance and alternative and adjunctive treatments have been developed. These include tamoxifen, dexamethasone, bromocriptine and aromatase inhibitors (AIs).

OBJECTIVES

To determine the relative effectiveness of anti-oestrogen agents, with or without medical adjuncts, in women with WHO group 2 anovulation.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trial register (searched 5th July 2004), CENTRAL (The Cochrane Library Issue 2 2004), MEDLINE (1966 to June 2004) and EMBASE (1980 to June 2004) for identification of relevant randomised controlled trials (RCTs). Additionally the United Kingdom National Institute for Clinical Excellence (NICE) guidelines and the references of relevant reviews and RCTs were searched.

SELECTION CRITERIA

RCTs that compare oral anti-oestrogen agents for ovulation induction (alone or in conjunction with medical adjuncts) in anovulatory subfertility, were considered for inclusion in the review. Metformin and other insulin sensitizing agents were not included. Hyperprolactinaemic infertility was not included.

DATA COLLECTION AND ANALYSIS

Data extraction and quality assessment was done independently by two reviewers. The primary outcome was live birth, secondary outcomes were: pregnancy, ovulation, miscarriage, multiple pregnancy, overstimulation, ovarian hyperstimulation syndrome and patient reported adverse effects.

MAIN RESULTS

Twelve RCTs were found and included in this review. No trials reported live birth as an outcome. Miscarriage and multiple pregnancy rates were poorly reported. Clomiphene was shown to be effective in increasing pregnancy rate when compared to placebo (fixed OR 5.8, 95% CI 1.6 to 21.5; NNT 5.9, 95% CI 3.6 to 16.7). No evidence of a difference in effect was found between clomiphene and tamoxifen (fixed OR 1.0, 95% CI 0.5 to 2.1). The use of clomiphene in combination with tamoxifen did not find any evidence of effect on pregnancy rate when compared to clomiphene alone (fixed OR 3.3, 95% CI 0.1 to 91.6). The comparison between two AIs (letrozole and anastrozole) did not find any evidence of a difference in effect on pregnancy rate (fixed OR 1.9, 95% CI 0.4 to 8.9). For the intervention of clomiphene plus ketoconazole vs clomiphene no evidence of a difference in effect for pregnancy rate was found (fixed OR 2.4, 95% CI 0.9 to 6.4). For clomiphene plus bromocriptine vs clomiphene no evidence of a difference in effect on pregnancy rate was found (fixed OR 1.0, 95% CI 0.3 to 3.0) rates. However, clomiphene plus dexamethasone treatment resulted in a significant improvement in the pregnancy rate (fixed OR 11.3, 95% CI 5.3 to 24.0; NNT 2.7, 95% CI 2.1 to 3.6) when compared to clomiphene alone as did clomiphene plus pretreatment with combined oral contraceptives (fixed OR 27.2, 95% CI 3.1 to 235.0; NNT 2.0, 95% CI 1.4 to 3.4).

AUTHORS' CONCLUSIONS

This review shows evidence supporting the effectiveness of the current first line treatment, clomiphene citrate. No evidence of a difference in effect was found between clomiphene and tamoxifen. The use of dexamethasone as an adjunct to clomiphene therapy appears promising as do combined oral contraceptives. This review has highlighted a gap in the literature on effects of these drugs on outcomes such as miscarriage rate. Evidence in favour of these interventions is flawed. RCTs of adequate power and of high methodological quality are required for the older treatments such as clomiphene, alone and with medical adjuncts, and also for the newer drugs such as the AIs.

PCOS: an ovarian disorder that leads to dysregulation in the hypothalamic–pituitary–adrenal axis?

This review focuses on the role of the ovaries in the pathogenesis of the polycystic ovarian syndrome. In particular, the failure of follicular development, hypothalamo-pituitary dysregulation, alterations in adrenal steroid output and derangement of intermediary metabolism are discussed in the context of the ovaries. It is concluded that the central and adrenal alterations associated with PCOS are unlikely to be primary but rather are secondary to the events within the ovary.

Is ovulation induction still a therapeutic problem in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases affecting women of fertile age, and is characterized by hyperandrogenism, chronic anovulatory cycles and oligomenorrhea or amenorrhea. Given the repercussions of chronic anovulation on sterility, PCOS is a heavy social burden. Here we describe the procedures used to induce ovulation in PCOS patients, the surgical approach and medical treatments that are still being experimented.

Monitoring plasma concentrations to individualize treatment with clomiphene citrate

OBJECTIVE

Recent reports have indicated that a number of individual patient characteristics are responsible for the success or failure of clomiphene citrate treatment. However, a priori individualization of doses in different patients has not been investigated. We examined the thesis that wide variability in the metabolism of the active component (zuclomiphene) contributes to variability in response.

METHODS

The dose-response relationship of clomiphene was established from a meta-analysis of data from 13 published reports. Limited data relating plasma drug concentrations to treatment outcome were examined to determine whether insufficient systemic exposure at a fixed dosage might contribute to therapeutic failure.

RESULTS

A fixed-dosage regimen of 50 mg clomiphene per day is likely to cause ovulation in only 46% of patients; subsequent increment in dosage increases the number of responders but at the expense of considerable delay in individualization of treatment. Case reports indicated that dosage based on plasma drug concentration monitoring could improve patient management, and an algorithm is proposed to facilitate treatment.

CONCLUSIONS

Prospective studies of clomiphene citrate should be performed to confirm the hypothesis that the monitoring of plasma zuclomiphene concentrations can significantly accelerate dose individualization and improve the therapeutic outcome with this "orphan" drug.

Treatment of the infertile patient with polycystic ovarian syndrome

Polycystic ovarian syndrome is associated with infertility due to anovulation caused by this disorder. Many treatments can increase both ovulation and fertility rates in these women. This is a comprehensive review of the literature, with an emphasis on randomized controlled trials of the medical and surgical treatment options for women with polycystic ovarian syndrome and infertility. Both standard and novel treatments are addressed. In the past, clomiphene citrate was the first-line medical treatment for subfertility in these women, followed by gonadotropins with or without gonadotropin releasing-hormone agonists for those women with clomiphene-resistance. Surgical treatments such as ovarian drilling were occasionally added to these regimens. The introduction of the insulin-sensitizing agents as adjuvants to clomiphene citrate and gonadotropins has changed the treatment strategy. The evidence in support of this change will be discussed. Data on the use of glucocorticoids, opioid receptor antagonists, and antiandrogens as adjuvants to standard therapies, as well as surgical treatments such as wedge resection and ovarian drilling will also be discussed. Based upon the evidence, medical treatment remains the primary therapy for women with this syndrome, especially in light of the recent introduction of insulin-sensitizing agents to the treatment armamentarium. These drugs have allowed us to develop less aggressive therapies that are safer and easier for women to utilize, and may in the future become the primary treatment for women with this syndrome.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to explain the pathophysiology of PCOS, to list the factors that predispose women to develop PCOS, and to outline the treatment regiments for PCOS-associated infertility.