Clomiphene citrate or letrozole as first-line ovulation induction drug in infertile PCOS women: A prospective randomized trial

Pharmacological and Non-Pharmacological Interventions for Polycystic Ovary Syndrome (PCOS) in Indian Women: A Systematic Review and Meta-Analysis

Background: Polycystic ovary syndrome (PCOS) is an endocrine disorder prevalent in women of reproductive age. Treatment or management of this syndrome includes several pharmacological and non-pharmacological treatment approaches for different manifestations of the disease that vary with the patient's age, symptoms, requirements, and geographical location. Objective: This systematic review aims to conduct a comprehensive and evidence-based analysis of the various available treatment options and identify knowledge gaps in PCOS management in India. Methods: A comprehensive search was conducted in PubMed, Scopus, and Embase databases from January 2010 till February 2024. We included randomized control trials (RCTs) using any pharmacological drugs (e.g., insulin sensitizers, anti-androgens, anti-obesity drugs, oral contraceptive pills, ovulation induction drugs, etc.) or non-pharmacological intervention (e.g., yoga, diet, herbal supplements, etc.) with Indian PCOS patients for improving common manifestations of PCOS and written in the English language. Studies were screened by two authors independently in a two-level process. Data extraction was also performed by two authors. Risk of bias was performed using the RoB 2 Tool. Subgroup analysis and meta-analysis were performed using the RevMan tool. Results: Thirty RCTs on pharmacological and eight on non-pharmacological interventions were included in the study. However, all the RCTs were so heterogeneous in terms of intervention used, subject recruited, and outcomes measured that meta-analysis was possible for only three subgroups (metformin vs. inositol, metformin vs. metformin+ inositol, and letrozole vs. clomiphene citrate), with only two or three studies per analysis. Most studies were single-centric and small-sized and had a high risk of bias, limiting their generalizability. Conclusions: This systematic review synthesized existing research and evaluated the effectiveness and safety of existing treatments. Limitations and gaps in the current research were identified, which may inform future research for better understanding and management of PCOS in the Indian context.

Differential Effects of Canonical Androgens and 11-Ketotestosterone on Reproductive Phenotypes and Folliculogenesis in Mouse Model of PCOS

Background: Polycystic ovary syndrome (PCOS) is a common female endocrine disorder characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. While canonical androgens like testosterone (T) and dihydrotestosterone (DHT) are well studied in PCOS pathophysiology, the role of 11-ketotestosterone (11KT) remains unclear. This study investigates the differential effects of these androgens on folliculogenesis, ovulation, and steroidogenesis using in vivo and in vitro models. Methods: Four-week-old female C57BL/6 mice received T, DHT, or 11KT for six weeks. The assessments included body weight, estrous cyclicity, serum hormone profiles, ovarian histology, and follicle classification. In parallel, large preantral follicles were cultured with each androgen to evaluate follicle growth, antrum formation, and ovulation capacity. Androgen receptor (AR) signaling and steroidogenic function were analyzed using western blotting, RT-qPCR, and luciferase reporter assays. Results: The DHT-treated mice exhibited increased weight gain, whereas 11KT-treated mice showed reduced weight gain. T and DHT disrupted the estrous cycle, while 11KT prolonged diestrus. All androgen treatments led to ovarian morphological changes, including follicular arrest and cystic features. In vitro, all androgens enhanced follicle growth, but only T and DHT inhibited ovulation. The AR expression was elevated across all androgen-treated groups, but only DHT significantly activated AR and CYP19A1 promoters. Conclusions: 11KT induces a distinct and milder PCOS-like phenotype compared to classical androgens, promoting follicle growth with minimal impact on ovulation or steroidogenic disruption. These findings underscore the heterogeneity of PCOS and suggest that different androgen profiles may drive diverse clinical phenotypes. By elucidating the distinct roles of different androgens, this may lead to better stratification of PCOS phenotypes based on predominant androgen types for more precise diagnosis and individualized management.

Letrozole Cotreatment Reduces Unexpectedly Poor Responses in Ovarian Stimulation With Follitropin Delta: A Strategy to Prevent High Anti-Müllerian Hormone (AMH) but Poor Response

BACKGROUND

Follitropin delta is a novel recombinant follicle-stimulating hormone preparation used for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). The dosage is determined using an original algorithm designed to achieve a target retrieval of 8-14 oocytes based on body weight and anti-Müllerian hormone (AMH) levels. However, unexpected poor responses, characterized by low oocyte retrieval numbers, occasionally occur in patients with high AMH levels who are otherwise expected to respond well. This study investigated whether cotreatment with letrozole reduces such poor responses.

METHODS

A retrospective cohort study including 153 controlled ovarian stimulation (COS) cycles for IVF/ICSI using follitropin delta was performed at Haruki Ladies Clinic in Japan from October 2021 to March 2023. In total, 42 cycles were performed in the letrozole cotreatment group, and 111 cycles were performed in the group treated with follitropin delta alone. According to the concept of follitropin delta, seven or fewer oocytes retrieved were defined as a poor response.

RESULTS

An unexpectedly poor response was observed at 6.0-6.9 µg daily doses of follitropin delta. The poor response was less frequent in the cotreatment group: one of 36 cycles (2.8%) in the cotreatment group and nine of 49 cycles (18.4%) in the follitropin delta alone group (p < 0.05). At daily doses of 7.0-11.9 μg, poor response was not often observed in both groups (0% vs. 3.6%). At 12.0 μg of daily dose, poor response frequently occurred in both groups. The duration of ovarian stimulation was decreased by cotreatment with letrozole (10.4 days vs. 8.7 days, p < 0.01). Letrozole cotreatment also reduced the total dosage of follitropin delta (65.2 µg vs. 53.3 µg, p < 0.01).

CONCLUSIONS

Cotreatment with letrozole may reduce unanticipated suboptimal responses in patients expected to have good responses. Additionally, it may shorten the duration of ovarian stimulation and decrease the total dosage of follitropin delta required.

Acupuncture for hormonal readiness and gut microbiota in obese polycystic ovary syndrome: an open-label, randomized controlled trial

Objective

To explore whether acupuncture combined with clomiphene can reduce the luteinizing hormone-to follicle-stimulating hormone ratio and impact the gut microbiota in patients with obese polycystic ovary syndrome.

Methods

This open-label, randomized, parallel-group controlled trial included 86 women aged 20-40 years with obese polycystic ovary syndrome and 19 healthy controls. Participants were randomly assigned to either an acupuncture combined with clomiphene group or a clomiphene-only group, with a healthy control group for comparison. The treatment lasted three menstrual cycles, with acupuncture administered three times weekly and clomiphene given daily from day five of menstruation for five consecutive days per cycle. The primary outcome was the change in the luteinizing hormone-to-follicle-stimulating hormone (LH/FSH) ratio. Secondary outcomes included levels of other sex hormones, glucose and lipid metabolism parameters, self-rating anxiety and depression scale scores, and gut microbiota composition.

Results

Intention-to-treat analysis showed that the adjusted mean luteinizing hormone-to follicle-stimulating hormone ratio decrease was -0.8 (95% CI: -1.14 to -0.46) in the acupuncture combined with clomiphene group and -0.22 (95% CI: -0.47 to 0.01) in the clomiphene group. The adjusted between-group difference was 0.53 (95% CI: 0.24 to 0.82, p < 0.001). The levels of Agathobacter faecis increased, and those of Erysipelatoclostridium spiroforme, Streptococcus lutetiensis, and Lactococcus lactis decreased after acupuncture combined with clomiphene treatment (p < 0.05).

Conclusion

Acupuncture combined with clomiphene may be safe and effective, reduce the luteinizing hormone-to follicle-stimulating hormone ratio, and improve insulin resistance in obese polycystic ovary syndrome, and these outcomes may be related to the gut microbiota.

Strong Early Impact of Letrozole on Ovulation Induction Outperforms Clomiphene Citrate in Polycystic Ovary Syndrome

Polycystic ovary syndrome is a common endocrine disorder, characterized by hyperandrogenism and/or chronic oligo/anovulation, which leads to infertility. The aim of this systematic review and meta-analysis was to explore the efficacy of letrozole compared with clomiphene citrate for ovulation induction in women with polycystic ovarian syndrome. The study protocol has been registered with PROSPERO (registration number CRD42022376611). The literature search included randomized clinical trials. We conducted our systematic literature search across three medical databases: MEDLINE (via PubMed), Cochrane Library (CENTRAL), and Embase. The data synthesis employed a random effects model. Out of the 1994 articles screened, 25 studies fulfilled the inclusion criteria. The letrozole group exhibited a significant increase in endometrial thickness (mean difference = 1.70, confidence interval: 0.55-2.86; I2 = 97%, p-value = 0.008). The odds of ovulation (odds ratio = 1.8, confidence interval: 1.21-2.69; I2 = 51%, p-value = 0.010) and pregnancy (odds ratio = 1.96, confidence interval: 1.37-2.81; I2 = 32%, p-value = 0.002) were significantly higher. The resistance index of the subendometrial arteries showed a significant decrease (mean difference = -0.15, confidence interval: -0.27 to -0.04; I2 = 92%, p-value = 0.030). Women diagnosed with polycystic ovarian syndrome and treated with letrozole for ovulation induction had increased ovulation and pregnancy rates and increased endometrial thickness. The lower resistance index of subendometrial arteries can enhance intrauterine circulation, creating more favorable conditions for embryo implantation and development.

Comparison of Letrozole and Clomiphene Citrate in Pregnancy Outcomes in Patients with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis

Clomiphene citrate (CC) and letrozole are the predominant medical interventions for the management of infertility in patients with polycystic ovary syndrome (PCOS). To comprehensively summarize the evidence, a systematic review and meta-analysis of randomized clinical trials (RCTs) was carried out to assess the effect of letrozole and CC on pregnancy outcomes in PCOS patients. We searched PubMed/MEDLINE, Scopus, and Cochrane Central Register of Controlled Trials from inception to January 2023. We included RCTs conducted on PCOS women comparing letrozole to CC and assessing endometrial thickness, the number and size of follicles, and ovulation and pregnancy rates. The endpoints were summarized as risk ratio (RR) or standardized mean difference (SMD) with 95% confidence interval (CI) using the random-effects model. Heterogeneity was examined using the I2 statistic. Fifty trials met our inclusion criteria. The mean endometrial thickness was significantly higher in the letrozole group compared to CC group (SMD: 0.89; 95% CI: 0.49, 1.28; I2=97.72%); however, the number of follicles was higher in the CC group (SMD: -0.56; 95% CI: -0.96, -0.17; I2=96.34%). Furthermore, letrozole intake induced higher ovulation rate (RR: 1.20; 95% CI: 1.13, 1.26; I2=54.49%) and pregnancy rate (RR: 1.44; 95% CI: 1.28, 1.62; I2=65.58%) compared to CC. Compared to CC, letrozole has a positive effect on endometrial thickness, monofollicular development, and ovulation and pregnancy rates suggesting that letrozole may be a strong alternative to CC as a first-line medical intervention for chronic anovulation in PCOS women. Larger studies are warranted to further clarify these findings.

Pregnancy Rates in Women With Polycystic Ovary Syndrome (PCOS) Using Letrozole Versus Clomiphene Citrate: A Retrospective Record Review

Background and objectives Polycystic ovary syndrome (PCOS) is a prominent cause of anovulation. Thus, this study aimed to compare the pregnancy rates of women with PCOS treated with letrozole (LE) or clomiphene citrate (CC) at King Abdulaziz University Hospital. Patients and methods A retrospective record review was conducted from April 2021 to August 2022 to review 1370 records of women with PCOS from January 2015 to December 2021. Sixty-one patients were included in this analysis. Chi-square tests and independent sample t-tests were used to analyze various associations. Statistical significance was set at P < 0.05. Results Letrozole was associated with a higher pregnancy rate (41.7%) than CC (32.0%). However, this relationship was not statistically significant (P = .619). Furthermore, patients treated with letrozole required fewer cycles to achieve pregnancy (two cycles compared to three cycles). The different age groups and body mass indexes did not affect the pregnancy rate in either group. Conclusion No significant difference was found between CC and LE in ovulation induction and outcome among PCOS patients. Studies with larger sample sizes and multiple centers should be conducted in Saudi Arabia to obtain more conclusive results, which will eventually lead to changes in guidelines for anovulation treatment in women with PCOS.

Letrozole Compared With Clomiphene Citrate for Polycystic Ovarian Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the effect of letrozole and clomiphene citrate in women with infertility and polycystic ovarian syndrome (PCOS).

METHODS OF STUDY SELECTION

MEDLINE through PubMed, Web of Science, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched for relevant studies from inception to February 1, 2022. Two reviewers retrieved, filtered, and extracted data independently using the bibliographic software EndNote X9 and Excel workbook. We included randomized controlled trials (RCTs) reporting ovulation induction outcomes in women with infertility and PCOS treated with either letrozole or clomiphene citrate followed by timed intercourse or intrauterine insemination. The data were merged into a mean difference or risk ratio (RR) with 95% CI, depending on variable types.

TABULATION, INTEGRATION, AND RESULTS

Data collection and organization were conducted in accordance with the 2020 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement. Twenty-nine RCTs were eligible, which included 3,952 women and 7,633 ovulation induction cycles. We acquired evidence from 22 RCTs for the ovulation rate, 28 RCTs for the clinical pregnancy rate, and eight RCTs for live-birth rate. Pooled analysis indicated that letrozole treatment prevailed against clomiphene citrate in ovulation rate (RR 1.14, 95% CI 1.06-1.21, P <.001), clinical pregnancy rate (RR 1.48, 95% CI 1.34-1.63, P <.001), and live-birth rate (RR 1.49, 95% CI 1.27-1.74, P <.001).

CONCLUSIONS

Letrozole was associated with improved ovulation, pregnancy, and live-birth rates compared with clomiphene citrate. We recommend letrozole over clomiphene citrate as an ovulation induction drug in women with infertility and PCOS, although the quality of the evidence is mixed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022308777.

Female infertility in the era of obesity: The clash of two pandemics or inevitable consequence?

Obesity is an epidemic that has led to a rise in the incidence of many comorbidities: among others, reduced fertility is often under-evaluated in clinical practice. The mechanisms underlying the link between reduced fertility and obesity are numerous, with insulin resistance, hyperglycaemia and the frequent coexistence of polycystic ovary syndrome being the most acknowledged. However, several other factors concur, such as gut microbiome alterations, low-grade chronic inflammation and oxidative stress. Not only do women with obesity take longer to conceive, but in vitro fertilization (IVF) is also less likely to succeed. We herein provide an updated state-of-the-art regarding the molecular bases of what we could define as dysmetabolic infertility, focusing on the clinical aspects, as well as possible treatment.

Effects of letrozole combined with ethinylestradiol and cyproterone acetate tablets on serum sex hormones and lipid metabolism in patients with polycystic ovary syndrome

OBJECTIVE

To investigate the effects of letrozole combined with ethinylestradiol and cyproterone acetate tablets on serum sex hormones and lipid metabolism in patients with polycystic ovary syndrome (PCOS).

METHODS

Clinical data of 152 PCOS patients in the First Affiliated Hospital of Guangxi University of Chinese Medicine from May 2019 to June 2021 were collected for a retrospective analysis. Among the patients, 73 treated with ethinylestradiol and cyproterone acetate tablets alone were seen as control group (CG), and the rest 79 with letrozole combined with ethinylestradiol and cyproterone acetate tablets were seen as observation group (OG). The treatment efficacy was observed, and the adverse reactions in the course of treatment were counted. The levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T), estrogen (E₂), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) were compared before and after treatment. The number of mature follicles, ovulation rate and pregnancy rate were assessed. Multivariate logistic regression analysis was used to detect the independent risk factors of ineffective efficacy.

RESULTS

After the treatment, the total efficacy rate of the OG was higher than that of the CG (P<0.05); moreover, the levels of TC, TG, LDL, FSH, LH and T in OG were lower while HDL and E₂ were higher (all P<0.05) than those of the CG. Also, the number of mature follicles, ovulation rate and pregnancy rate were higher in OG than those in the CG (all P<0.05). There was no obvious difference in the incidence of adverse reactions between the groups (P>0.05). Higher fasting glucose, higher Ferriman-Gallway hair score, single drug treatment regimen, higher systolic blood pressure, and lower E₂ before treatment were independent risk factors for ineffective treatment efficacy.

CONCLUSION

Letrozole combined with ethinylestradiol and cyproterone acetate tablets can enhance the treatment efficiency of PCOS and improve serum sex hormones and lipid metabolism in PCOS patients.

Aromatase inhibitors (letrozole) for ovulation induction in infertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 5% to 20% of women worldwide and often leads to anovulatory infertility. Aromatase inhibitors (AIs) are a class of drugs that were introduced for ovulation induction in 2001. Since about 2001 clinical trials have reached differing conclusions as to whether the AI, letrozole, is at least as effective as the first-line treatment clomiphene citrate (CC), a selective oestrogen receptor modulator (SERM).

OBJECTIVES

To evaluate the effectiveness and safety of AIs (letrozole) (with or without adjuncts) compared to SERMs (with or without adjuncts) for infertile women with anovulatory PCOS for ovulation induction followed by timed intercourse or intrauterine insemination.

SEARCH METHODS

We searched the following sources, from their inception to 4 November 2021, to identify relevant randomised controlled trials (RCTs): the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase and PsycINFO. We also checked reference lists of relevant trials, searched the trial registers and contacted experts in the field for any additional trials. We did not restrict the searches by language or publication status.

SELECTION CRITERIA

We included all RCTs of AIs used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed risks of bias using RoB 1. We pooled trials where appropriate using a fixed-effect model to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes, and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth rate and OHSS rate. Secondary outcomes were clinical pregnancy, miscarriage and multiple pregnancy rates. We assessed the certainty of the evidence for each comparison using GRADE methods.

MAIN RESULTS

This is a substantive update of a previous review; of six previously included trials, we excluded four from this update and moved two to 'awaiting classification' due to concerns about validity of trial data. We included five additional trials for this update that now includes a total of 41 RCTs (6522 women). The AI, letrozole, was used in all trials. Letrozole compared to SERMs with or without adjuncts followed by timed intercourse Live birth rates were higher with letrozole (with or without adjuncts) compared to SERMs followed by timed intercourse (OR 1.72, 95% CI 1.40 to 2.11; I2 = 0%; number needed to treat for an additional beneficial outcome (NNTB) = 10; 11 trials, 2060 participants; high-certainty evidence). This suggests that in women with a 20% chance of live birth using SERMs, the live birth rate in women using letrozole with or without adjuncts would be 27% to 35%. There is high-certainty evidence that OHSS rates are similar with letrozole or SERMs (0.5% in both arms: risk difference (RD) -0.00, 95% CI -0.01 to 0.01; I2 = 0%; 10 trials, 1848 participants; high-certainty evidence). There is evidence for a higher pregnancy rate in favour of letrozole (OR 1.69, 95% CI 1.45 to 1.98; I2 = 0%; NNTB = 10; 23 trials, 3321 participants; high-certainty evidence). This suggests that in women with a 24% chance of clinical pregnancy using SERMs, the clinical pregnancy rate in women using letrozole with or without adjuncts would be 32% to 39%. There is little or no difference between treatment groups in the rate of miscarriage per pregnancy (25% with SERMs versus 24% with letrozole: OR 0.94, 95% CI 0.66 to 1.32; I2 = 0%; 15 trials, 736 participants; high-certainty evidence) and multiple pregnancy rate (2.2% with SERMs versus 1.6% with letrozole: OR 0.74, 95% CI 0.42 to 1.32; I2 = 0%; 14 trials, 2247 participants; high-certainty evidence). However, a funnel plot showed mild asymmetry, indicating that some trials in favour of SERMs might be missing.  Letrozole compared to laparoscopic ovarian drilling (LOD) One trial reported very low-certainty evidence that live birth rates may be higher with letrozole compared to LOD (OR 2.07, 95% CI 0.99 to 4.32; 1 trial, 141 participants; very low-certainty evidence). This suggests that in women with a 22% chance of live birth using LOD with or without adjuncts, the live birth rate in women using letrozole with or without adjuncts would be 24% to 47%. No trial reported OHSS rates. Due to the low-certainty evidence we are uncertain if letrozole improves pregnancy rates compared to LOD (OR 1.47, 95% CI 0.95 to 2.28; I² = 0%; 3 trials, 367 participants; low-certainty evidence). This suggests that in women with a 29% chance of clinical pregnancy using LOD with or without adjuncts, the clinical pregnancy rate in women using letrozole with or without adjuncts would be 28% to 45%. There seems to be no evidence of a difference in miscarriage rates per pregnancy comparing letrozole to LOD (OR 0.65, 95% CI 0.22 to 1.92; I² = 0%; 3 trials, 122 participants; low-certainty evidence). This also applies to multiple pregnancies (OR 3.00, 95% CI 0.12 to 74.90; 1 trial, 141 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth rates and pregnancy rates in infertile women with anovulatory PCOS, compared to SERMs, when used for ovulation induction, followed by intercourse. There is high-certainty evidence that OHSS rates are similar with letrozole or SERMs. There was high-certainty evidence of no difference in miscarriage rate and multiple pregnancy rate. We are uncertain if letrozole increases live birth rates compared to LOD. In this update, we added good quality trials and removed trials with concerns over data validity, thereby upgrading the certainty of the evidence base.

The Improvement Effect of D-Chiro-Inositol and Ecklonia cava K. in the Rat Model of Polycystic Ovarian Syndrome

Introduction: Polycystic Ovarian Syndrome (PCOS) is known to be an endocrine state that is characterized by oligomenorrhea, hyperandrogenism, and highly cystic follicles in the ovaries. The use of food ingredients and traditional medicine in Asian countries is well known, and previous studies have shown that Ecklonia cava K. [Alariaceae] (EC) is able to alleviate PCOS symptoms. D-Chiro-inositol (DCI) administration in pathologies where steroid biosynthesis is a crucial factor, i.e., PCOS, has provided satisfactory results.

Methods: Therefore, we studied the synergistic effects of the two previously known active compounds. In rats with letrozole-induced PCOS, we focused on alternative therapies using EC and/or DCI extracts to alleviate ovarian failure.

Results: As a nonsteroidal aromatase inhibitor, letrozole inhibits the conversion of testosterone to estrogen and subsequently causes PCOS. We divided 6-week-old female mice into the following six groups and evaluated them: vehicle, PCOS, PCOS + MET (metformin), PCOS + DCI, PCOS + EC, and PCOS + DCI + EC. In our study, PCOS rats treated with EC and DCI had low serum LH and T levels and low serum levels of inflammatory cytokines such as TNFα and IL-6. These treatments also appeared to regulate the production of factors that affect follicle formation and inflammation in the ovaries.

Conclusion: We concluded that EC extract and/or DCI administration influenced aromatase production and reduced LH and T stimulation, and cotreatment with EC and DCI consequently restored ovarian dysfunction or anti-inflammatory responses in rats with PCOS-like symptoms.

Metformin With or Without Clomiphene Citrate Versus Laparoscopic Ovarian Drilling With or Without Clomiphene Citrate to Treat Patients With Clomiphene Citrate-Resistant Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Introduction: Which is optimal to treat clomiphene citrate-resistant polycystic ovary syndrome (CCR-PCOS) with LOD or metformin remains a problem. There are three inconsistent or even contradictory views.

Objectives: The present meta-analysis aimed to evaluate the effectiveness and safety of Metformin with or without CC and to compare them with LOD with or without CC (Met/Met-CC vs. LOD/LOD-CC) in women with CCR-PCOS who also have anovulation.

Data source: The PubMed, Cochrane, and Embase databases were searched to identify relevant studies reported between 1 Jan 1966 and 31 Aug 2019; the search was updated on 17 May 2022.

Study eligibility criteria: We included randomized controlled trials (RCTs) of CCR-PCOS that had considered Met/Met-CC and LOD/LOD-CC as the exposure variables and fertility as the main outcome variable.

Study appraisal and synthesis methods: We assessed study quality using the Cochrane risk-of-bias tool. The primary effectiveness outcome was live birth/ongoing pregnancy rate and the primary safety outcome was miscarriage rate. A fixed-effect meta-analysis was performed. The robustness of the results was assessed using sensitivity analyses. Meta-regression and subgroup analysis were performed to examine the reasons for heterogeneity. Publication bias was examined using the funnel plot, Egger linear regression, and Begg rank correlation tests. The quality of this meta-analysis was estimated according to the GRADE approach. This meta-analysis has been registered in PROSPERO (CRD42021240156).

Results: Among 71 potentially relevant studies, we included five RCTs in our meta-analysis. We found no difference in effectiveness between Met-CC and LOD in terms of live birth/ongoing pregnancy (RR = 1.02, 95% CI: 0.87–1.21, z = 0.28; p = 0.780), and miscarriage rates (RR = 0.79, 95% CI: 0.46–1.36, z = 0.86; p = 0.390). I2 tests results revealed moderate or no heterogeneity (I2 = 51.4%, p = 0.083; I2= 0.0%; p = 0.952). Sensitivity analysis confirmed the robustness of the results. Funnel plot, Egger linear regression, and Begg rank correlation tests implied no publication bias (p &gt; 0.05). LOD was more expensive than Met (€1050 vs. €50.16). The evidence quality was moderate.

Conclusion: There is no evidence on the difference in the outcomes between the two interventions regarding ovulation, pregnancy, and live birth. As LOD is an invasive procedure and carries inherent risks, the use of Met/Met-CC should be the second-line treatment for women with CCR-PCOS.

Systematic Review Registration: identifier CRD42021240156.

The effect of mildly stimulated cycle versus artificial cycle on pregnancy outcomes in overweight/obese women with PCOS prior to frozen embryo transfer: a retrospective cohort study

Background

Previous studies have shown that frozen embryo transfer (FET) resulted in increased live birth rates (LBR) and reduced the risk of ovarian hyperstimulation syndrome (OHSS) than did fresh embryo transfer in women with polycystic ovary syndrome (PCOS). In addition, overweight/obese women with PCOS are at increased risk of subfertility and complications of pregnancy, compared with normal-weight women. The ovarian stimulation and artificial hormone regimes are the two more commonly used endometrial preparation protocols in PCOS patients.This retrospective study aims to compare the pregnancy outcomes of mildly stimulated cycles (mSTC) and artificial cycles (AC) prior to FET in overweight/obese women with PCOS.

Methods

A retrospective analysis was conducted in overweight/obese women with PCOS who underwent their first FET cycles from January 2018 to December 2020. Two endometrial preparation protocols were used: the mildly stimulated cycles (N = 173) and the artificial cycles (N = 507). All pregnancy outcomes were analyzed by Student’s t-test, Chi-square (χ²) statistics and multivariable logistic regression analyses.

Results

This study enrolled 680 cases of FET cycles. The mSTC group exhibited significantly higher LBR compared with the AC group (49.7% vs. 41.0%; P = 0.046), while the rate of miscarriage was significantly lower (6.4% vs. 23.0%; P < 0.001). No statistically significant differences were observed in positive pregnancy rate (57.8% vs. 60.0%, P = 0.618), clinical pregnancy rate (54.3% vs. 55.6%, P = 0.769), and ectopic pregnancy rate (2.1% vs. 3.2%, P = 0.860) between two groups. After adjusting for possible confounding factors, multivariate logistic regression analysis also yielded similar results.

Conclusions

For overweight/obese women with PCOS, mSTC-FET demonstrated a higher LBR and a lower pregnancy loss rate than that in the AC-FET. When considering the most cost-effective treatment with the least adverse effects on patients, the mSTC for FET endometrial preparation may be considered. To corroborate our findings, additional prospective randomized clinical trials with larger sample sizes are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04728-6.

The Effect of Clomiphene Citrate and Letrozole in Apoptotic Pathways and Cell Cycle in Human Primary Cumulus Cells and the Protective Effect of Estradiol

Clomiphene citrate (CC) and letrozole are ovulatory stimulants that, despite high ovulation rates, achieve low pregnancy rates. This study aimed to investigate the in vitro effects of CC and letrozole, alone or in combination with estradiol, on apoptosis in human cumulus cells. We performed a controlled prospective study using primary cumulus cell cultures from patients undergoing in vitro fertilization (n=22). Alpha-inhibin immunocytochemistry was used to assess cell culture purity and morphology. Cell viability was evaluated by MTT assay, cell cycle status by flow cytometry, and Caspase-3, Bax and SOD-2, and S26 gene expression by qPCR. Cells were treated for 24 hours in 5 conditioned media: CC, CC + estradiol, letrozole, letrozole + estradiol and control. None of the treatments affected cell viability, but letrozole reduced the mean percentage of cells in the S phase compared to control (24.79 versus 21.70, p=0.0014). Clomiphene treatment increased mRNA expression of Bax (4 fold) and SOD-2 (2 fold), which was reversed by co-treatment with estradiol. SOD-2 expression increased in cells treated with letrozole compared to control (4 fold), which was also reversed by estradiol. These findings suggest that clomiphene citrate and letrozole do not significantly affect the viability of human cumulus cells. Still, the expression of genes involved in apoptosis was modulated by these drugs alone and in association with estradiol, suggesting that CC and letrozole may have direct effects on cumulus cells beyond their known mechanisms of action.

Higher ovulation rate with letrozole as compared with clomiphene citrate in infertile women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common cause of anovulatory infertility. According to the latest guidelines, letrozole should be considered as the first-line pharmacological treatment for women with WHO Group II anovulation or PCOS. However, the use of letrozole as an ovulation induction agent is not FDA or EMA approved, and its use is "off-label." The main concern with respect to letrozole regards its potential teratogenic effect on the fetus.

PURPOSE

To determine whether the probability of ovulation is higher with letrozole as compared to clomiphene citrate (CC) in anovulatory women with PCOS.

METHODS

Randomized controlled trials (RCTs) comparing letrozole versus CC used for ovulation induction in infertile women with PCOS followed by timed intercourse (TI) or intrauterine insemination (IUI) were included in this meta-analysis. Primary outcome was ovulation. Secondary outcomes were live birth, clinical pregnancy, miscarriage, multiple pregnancy, and congenital anomalies. Subgroup analysis included patients who received letrozole or CC as first-line treatment, and patients with PCOS diagnosed according to the Rotterdam criteria.

RESULTS

Twenty-six RCTs published between 2006 and 2019, involving 4168 patients who underwent 8310 cycles of ovulation induction, were included. The probability of ovulation was significantly higher in letrozole as compared to CC cycles (RR: 1.148, 95% CI: 1.077 to 1.223, 3017 women, 19 trials, I²: 47.7%, low-quality evidence).

CONCLUSION

A higher probability of ovulation is expected in infertile patients with PCOS treated with letrozole as compared to CC. The higher ovulation rate might have contributed to the higher clinical pregnancy and live birth rate. This finding is also true for patients who were administered letrozole as first-line treatment.

TRIAL REGISTRATION

CRD42019125166.

Differences in the individual curative effect of acupuncture for obese women with polycystic ovary syndrome based on metagenomic analysis: study protocol for a randomized controlled trial

BACKGROUND

Polycystic ovary syndrome is a common cause of infertility and shows a high incidence in women of reproductive age. Acupuncture is an appropriate adjunctive treatment for PCOS. However, the add-on effect of acupuncture as an adjunctive treatment for obese women with PCOS has not been studied, and previous studies indicate that there are individual differences in the curative effect of acupuncture, while deeper research on the mechanism of differences in the individual curative effect of acupuncture for obese women with PCOS is still lacking. This trial aims to assess the add-on treatment efficacy of acupuncture for obese women with PCOS and to explore the role of the gut microbiome on the differences in the individual curative effect of acupuncture based on metagenomic analysis.

METHODS/DESIGN

This is an open-label, randomized, controlled trial. A total of 86 obese women with PCOS will be recruited. Subjects will be randomly assigned to a study group and a control group in a 1:1 ratio, with 43 subjects in each group (10 patients from each group who meet the study criteria will participate in the metagenomic analysis). An additional 10 subjects who meet the study criteria will be recruited to a healthy control group. The study group will receive acupuncture and clomiphene citrate treatment; the control group will only receive clomiphene citrate. Acupuncture treatment will be conducted three times a week from the fifth day of menstruation or withdrawal bleeding until the start of the next menstruation, for up to three menstrual cycles. The primary outcome will be LH/FSH. The secondary outcomes will comprise biometric features, hormone biomarkers, metabolic biomarkers, inflammatory biomarkers, Self-Rating Anxiety Scale, Self-Rating Depression Scale, and metagenomic analysis. The outcomes will be measured at baseline and post-intervention. Data will be analyzed using SPSS 19.0, and the gut microbiome will be analyzed using metagenomic analysis.

DISCUSSION

In this study, we are evaluating the add-on effects of acupuncture and exploring the mechanism of the differences in the individual curative effect of acupuncture based on the gut microbiome, which may provide evidence to explain the different outcomes of different trials on acupuncture for PCOS and hopefully to provide a new aspect to study the mechanism of acupuncture's treatment effect.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000029882 . Registered on 16 February 2020.

To share or not to share data: how valid are trials evaluating first-line ovulation induction for polycystic ovary syndrome?

BACKGROUND

In our recent individual participant data (IPD) meta-analysis evaluating the effectiveness of first-line ovulation induction for polycystic ovary syndrome (PCOS), IPD were only available from 20 studies of 53 randomized controlled trials (RCTs). We noticed that the summary effect sizes of meta-analyses of RCTs without IPD sharing were different from those of RCTs with IPD sharing. Granting access to IPD for secondary analysis has implications for promoting fair and transparent conduct of RCTs. It is, however, still common for authors to choose to withhold IPD, limiting the impact of and confidence in the results of RCTs and systematic reviews based on aggregate data.

OBJECTIVE AND RATIONALE

We performed a meta-epidemiologic study to elucidate if RCTs without IPD sharing have lower quality and more methodological issues than those with IPD sharing in an IPD meta-analysis evaluating first-line ovulation induction for PCOS.

SEARCH METHODS

We included RCTs identified for the IPD meta-analysis. We dichotomized RCTs according to whether they provided IPD (shared group) or not (non-shared group) in the IPD meta-analysis. We restricted RCTs to full-text published trials written in English.

We assessed and compared RCTs in the shared and non-shared groups on the following criteria: Risk of Bias (RoB 2.0), GRADE approach, adequacy of trial registration; description of statistical methods and reproducibility of univariable statistical analysis; excessive similarity or difference in baseline characteristics that is not compatible with chance; and other miscellaneous methodological issues.

OUTCOMES

In total, 45 trials (8697 women) were included in this study. IPD were available from 17 RCTs and 28 trials were categorized as the non-shared IPD group. Pooled risk rates obtained from the shared and non-shared groups were different. Overall low risk of bias was associated with 13/17 (76%) of shared RCTs versus 7/28 (25%) of non-shared RCTs. For RCTs that started recruitment after 1 July 2005, adequate trial registration was found in 3/9 (33%) of shared IPD RCTs versus 0/16 (0%) in non-shared RCTs. In total, 7/17 (41%) of shared RCTs and 19/28 (68%) of non-shared RCTs had issues with the statistical methods described. The median (range) of inconsistency rate per study, between reported and reproduced analyses for baseline variables, was 0% (0–92%) (6 RCTs applicable) in the shared group and 54% (0–100%) (13 RCTs applicable) in the non-shared group. The median (range) of inconsistency rate of univariable statistical results for the outcome(s) per study was 0% (0–63%) (14 RCTs applicable) in the shared group and 44% (0–100%) (24 RCTs applicable) in the non-shared group. The distributions of simulation-generated P-values from comparisons of baseline continuous variables between intervention and control arms suggested that RCTs in the shared group are likely to be consistent with properly conducted randomization (P = 0.163), whereas this was not the case for the RCTs in the non-shared group (P = 4.535 × 10−8).

WIDER IMPLICATIONS

IPD meta-analysis on evaluating first-line ovulation induction for PCOS preserves validity and generates more accurate estimates of risk than meta-analyses using aggregate data, which enables more transparent assessments of benefits and risks. The availability of IPD and the willingness to share these data may be a good indicator of quality, methodological soundness and integrity of RCTs when they are being considered for inclusion in systematic reviews and meta-analyses.

Removal of DHT can relieve polycystic ovarian but not metabolic abnormalities in DHT-induced hyperandrogenism in mice

Polycystic ovary syndrome (PCOS) is an endocrine disorder with a high prevalence in women of childbearing age. To date, there is no method of efficiently diagnosing PCOS and curing it completely because its pathomechanism remains unclear. Here, we investigated whether metabolic abnormalities maintain the hyperandrogenism and PCOS-like ovaries and whether the symptoms induced by excess androgen are treatable. We ceased the abnormal dihydrotestosterone (DHT) stimulation to determine changes in PCOS-like mice. After ceasing DHT stimulation, the ovarian morphology and gene expression recovered from the DHT-stimulated status. However, after cessation of DHT stimulation, the hypertrophy of adipose tissues and hepatic steatosis were not significantly restored, and fat accumulation-related gene expression and serum metabolic markers in the mice were altered. These findings showed that the reproductive dysfunction was obviously relieved, but because the metabolic abnormalities were not relieved after the cessation of excess androgen for 30 days, it appears that the latter may not maintain the former.

First-line ovulation induction for polycystic ovary syndrome: an individual participant data meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most frequent cause of anovulatory infertility. In women with PCOS, effective ovulation induction serves as an important first-line treatment for anovulatory infertility. Individual participant data (IPD) meta-analysis is considered as the gold standard for evidence synthesis which provides accurate assessments of outcomes from primary randomised controlled trials (RCTs) and allows additional analyses for time-to-event outcomes. It also facilitates treatment-covariate interaction analyses and therefore offers an opportunity for personalised medicine.

OBJECTIVE AND RATIONALE

We aimed to evaluate the effectiveness of different ovulation induction agents, in particular letrozole alone and clomiphene citrate (CC) plus metformin, as compared to CC alone, as the first-line choice for ovulation induction in women with PCOS and infertility, and to explore interactions between treatment and participant-level baseline characteristics.

SEARCH METHODS

We searched electronic databases including MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials up to 20 December 2018. We included RCTs comparing the following interventions with each other or placebo/no treatment in women with PCOS and infertility: CC, metformin, CC plus metformin, letrozole, gonadotrophin and tamoxifen. We excluded studies on treatment-resistant women. The primary outcome was live birth. We contacted the investigators of eligible RCTs to share the IPD and performed IPD meta-analyses. We assessed the risk of bias by using the Cochrane risk of bias tool for RCTs.

OUTCOMES

IPD of 20 RCTs including 3962 women with PCOS were obtained. Six RCTs compared letrozole and CC in 1284 women. Compared with CC, letrozole improved live birth rates (3 RCTs, 1043 women, risk ratio [RR] 1.43, 95% confidence interval [CI] 1.17-1.75, moderate-certainty evidence) and clinical pregnancy rates (6 RCTs, 1284 women, RR 1.45, 95% CI 1.23-1.70, moderate-certainty evidence) and reduced time-to-pregnancy (6 RCTs, 1235 women, hazard ratio [HR] 1.72, 95% CI 1.38-2.15, moderate-certainty evidence). Meta-analyses of effect modifications showed a positive interaction between baseline serum total testosterone levels and treatment effects on live birth (interaction RR 1.29, 95% CI 1.01-1.65). Eight RCTs compared CC plus metformin to CC alone in 1039 women. Compared with CC alone, CC plus metformin might improve clinical pregnancy rates (8 RCTs, 1039 women, RR 1.18, 95% CI 1.00-1.39, low-certainty evidence) and might reduce time-to-pregnancy (7 RCTs, 898 women, HR 1.25, 95% CI 1.00-1.57, low-certainty evidence), but there was insufficient evidence of a difference on live birth rates (5 RCTs, 907 women, RR 1.08, 95% CI 0.87-1.35, low-certainty evidence). Meta-analyses of effect modifications showed a positive interaction between baseline insulin levels and treatment effects on live birth in the comparison between CC plus metformin and CC (interaction RR 1.03, 95% CI 1.01-1.06).

WIDER IMPLICATIONS

In women with PCOS, letrozole improves live birth and clinical pregnancy rates and reduces time-to-pregnancy compared to CC and therefore can be recommended as the preferred first-line treatment for women with PCOS and infertility. CC plus metformin may increase clinical pregnancy and may reduce time-to-pregnancy compared to CC alone, while there is insufficient evidence of a difference on live birth. Treatment effects of letrozole are influenced by baseline serum levels of total testosterone, while those of CC plus metformin are affected by baseline serum levels of insulin. These interactions between treatments and biomarkers on hyperandrogenaemia and insulin resistance provide further insights into a personalised approach for the management of anovulatory infertility related to PCOS.

Evidence summaries and recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome: assessment and treatment of infertility

STUDY QUESTION

What is the recommended assessment and management of infertile women with polycystic ovary syndrome (PCOS), based on the best available evidence, clinical expertize and consumer preference?

SUMMARY ANSWER

International evidence-based guidelines, including 44 recommendations and practice points, addressed prioritized questions to promote consistent, evidence-based care and improve the experience and health outcomes of infertile women with PCOS.

WHAT IS KNOWN ALREADY

Previous guidelines on PCOS lacked rigorous evidence-based processes, failed to engage consumer and multidisciplinary perspectives or were outdated. The assessment and management of infertile women with PCOS are inconsistent. The needs of women with PCOS are not being adequately met and evidence practice gaps persist.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Governance included a six continent international advisory and a project board, a multidisciplinary international guideline development group (GDG), consumer and translation committees. Extensive health professional and consumer engagement informed the guideline scope and priorities. The engaged international society-nominated panel included endocrinology, gynaecology, reproductive endocrinology, obstetrics, public health and other experts, alongside consumers, project management, evidence synthesis and translation experts. Thirty-seven societies and organizations covering 71 countries engaged in the process. Extensive online communication and two face-to-face meetings over 15 months addressed 19 prioritized clinical questions involving nine evidence-based reviews and 10 narrative reviews. Evidence-based recommendations (EBRs) were formulated prior to consensus voting within the guideline panel.

STUDY DESIGN, SIZE, DURATION

International evidence-based guideline development engaged professional societies and consumer organizations with multidisciplinary experts and women with PCOS directly involved at all stages. A (AGREE) II-compliant processes were followed, with extensive evidence synthesis. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was applied across evidence quality, desirable and undesirable consequences, feasibility, acceptability, cost, implementation and ultimately recommendation strength. The guideline was peer-reviewed by special interest groups across our partner and collaborating societies and consumer organizations, was independently assessed against AGREE II criteria and underwent methodological review. This guideline was approved by all members of the GDG and has been approved by the NHMRC.

MAIN RESULTS AND THE ROLE OF CHANCE

The quality of evidence (QOE) for the EBRs in the assessment and management of infertility in PCOS included very low (n = 1), low (n = 9) and moderate (n = 4) quality with no EBRs based on high-quality evidence. The guideline provides 14 EBRs, 10 clinical consensus recommendations (CCRs) and 20 clinical practice points on the assessment and management of infertility in PCOS. Key changes in this guideline include emphasizing evidence-based fertility therapy, including cheaper and safer fertility management.

LIMITATIONS, REASONS FOR CAUTION

Overall evidence is generally of low to moderate quality, requiring significantly greater research in this neglected, yet common condition. Regional health systems vary and a process for adaptation of this guideline is provided.

WIDER IMPLICATIONS OF THE FINDINGS

The international guideline for the assessment and management of infertility in PCOS provides clinicians with clear advice on best practice based on the best available evidence, expert multidisciplinary input and consumer preferences. Research recommendations have been generated and a comprehensive multifaceted dissemination and translation program supports the guideline with an integrated evaluation program.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was primarily funded by the Australian National Health and Medical Research Council of Australia (NHMRC) supported by a partnership with ESHRE and the American Society for Reproductive Medicine (ASRM). GDG members did not receive payment. Travel expenses were covered by the sponsoring organizations. Disclosures of conflicts of interest were declared at the outset and updated throughout the guideline process, aligned with NHMRC guideline processes. Dr Costello has declared shares in Virtus Health and past sponsorship from Merck Serono for conference presentations. Prof. Norman has declared a minor shareholder interest in the IVF unit Fertility SA, travel support from Merck and grants from Ferring. Prof. Norman also has scientific advisory board duties for Ferring. The remaining authors have no conflicts of interest to declare.

This article was not externally peer-reviewed by Human Reproduction Open.

The impact of ovarian stimulation on the outcome of intrauterine insemination treatment: an analysis of 8893 cycles

OBJECTIVE

To evaluate the impact of ovarian stimulation on the outcome of intrauterine insemination (IUI).

DESIGN

Retrospective analysis.

SETTING

A single university-based centre.

POPULATION

A total of 5109 couples with 8893 cycles.

METHODS

The outcome of IUI with different protocols for ovarian stimulation was examined.

MAIN OUTCOME MEASURES

The live birth rate (LBR), twin pregnancy rate and ovarian hyperstimulation syndrome (OHSS).

RESULTS

In ovulatory women without ovarian stimulation, the LBR was 7.6%. Stimulation with clomifene citrate (CC), letrozole (LE), human menopausal gonadotrophin (HMG), CC or LE combined with HMG achieved LBRs of 6.1, 5, 7.9, 8 and 12.2%, respectively. LE combined with HMG achieved a significantly improved LBR compared with no stimulation. HMG stimulation was associated with a higher rate of twins (7.4%) than no stimulation (0%, P < 0.01). In ovulatory women, the LBR appeared lower in CC and LE compared with no stimulation (P > 0.05). In anovulatory women, ovarian stimulation with CC, LE, HMG, CC or LE combined with HMG achieved LBRs of 11.3, 5.1, 11.8, 12.6 and 13.6%, respectively. No significant difference was observed. There were no triplet pregnancies or OHSS in stimulated cycles.

CONCLUSIONS

In ovulatory women, ovarian stimulation with LE combined with HMG achieved a significantly improved live birth rate. HMG stimulation resulted in a high risk for twins.

TWEETABLE ABSTRACT

In ovulatory women, ovarian stimulation with letrozole and HMG resulted in a significantly improved LBR.

Aromatase inhibitors (letrozole) for subfertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a class of drugs that were introduced for ovulation induction in 2001. Since about 2001 clinical trials have reached differing conclusions as to whether the AI letrozole is at least as effective as the first-line treatment clomiphene citrate (CC).

OBJECTIVES

To evaluate the effectiveness and safety of aromatase inhibitors for subfertile women with anovulatory PCOS for ovulation induction followed by timed intercourse or intrauterine insemination (IUI).

SEARCH METHODS

We searched the following sources from inception to November 2017 to identify relevant randomised controlled trials (RCTs): the Cochrane Gynaecology and Fertility Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, Pubmed, LILACS, Web of Knowledge, the World Health Organization (WHO) clinical trials register and Clinicaltrials.gov. We also searched the references of relevant articles. We did not restrict the searches by language or publication status.

SELECTION CRITERIA

We included all RCTs of AIs used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed risks of bias. We pooled studies where appropriate using a fixed-effect model to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes, and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth and OHSS. Secondary outcomes were clinical pregnancy, miscarriage and multiple pregnancy. We assessed the quality of the evidence for each comparison using GRADE methods.

MAIN RESULTS

This is a substantive update of a previous review. We identified 16 additional studies for the 2018 update. We include 42 RCTs (7935 women). The aromatase inhibitor letrozole was used in all studies.Letrozole compared to clomiphene citrate (CC) with or without adjuncts followed by timed intercourseLive birth rates were higher with letrozole (with or without adjuncts) compared to clomiphene citrate (with our without adjuncts) followed by timed intercourse (OR 1.68, 95% CI 1.42 to 1.99; 2954 participants; 13 studies; I² = 0%; number needed to treat for an additional beneficial outcome (NNTB) = 10; moderate-quality evidence). There is high-quality evidence that OHSS rates are similar with letrozole or clomiphene citrate (0.5% in both arms: risk difference (RD) -0.00, 95% CI -0.01 to 0.00; 2536 participants; 12 studies; I² = 0%; high-quality evidence). There is evidence for a higher pregnancy rate in favour of letrozole (OR 1.56, 95% CI 1.37 to 1.78; 4629 participants; 25 studies; I² = 1%; NNTB = 10; moderate-quality evidence). There is little or no difference between treatment groups in the rate of miscarriage by pregnancy (20% with CC versus 19% with letrozole; OR 0.94, 95% CI 0.70 to 1.26; 1210 participants; 18 studies; I² = 0%; high-quality evidence) and multiple pregnancy rate (1.7% with CC versus 1.3% with letrozole; OR 0.69, 95% CI 0.41 to 1.16; 3579 participants; 17 studies; I² = 0%; high-quality evidence). However, a funnel plot showed mild asymmetry, indicating that some studies in favour of clomiphene might be missing.Letrozole compared to laparoscopic ovarian drillingThere is low-quality evidence that live birth rates are similar with letrozole or laparoscopic ovarian drilling (OR 1.38, 95% CI 0.95 to 2.02; 548 participants; 3 studies; I² = 23%; low-quality evidence). There is insufficient evidence for a difference in OHSS rates (RD 0.00, 95% CI -0.01 to 0.01; 260 participants; 1 study; low-quality evidence). There is low-quality evidence that pregnancy rates are similar (OR 1.28, 95% CI 0.94 to 1.74; 774 participants; 5 studies; I² = 0%; moderate-quality evidence). There is insufficient evidence for a difference in miscarriage rate by pregnancy (OR 0.66, 95% CI 0.30 to 1.43; 240 participants; 5 studies; I² = 0%; moderate-quality evidence), or multiple pregnancies (OR 3.00, 95% CI 0.12 to 74.90; 548 participants; 3 studies; I² = 0%; low-quality evidence).Additional comparisons were made for Letrozole versus placebo, Selective oestrogen receptor modulators (SERMS) followed by intrauterine insemination (IUI), follicle stimulating hormone (FSH), Anastrozole, as well as dosage and administration protocols. There is insufficient evidence for a difference in either group of treatment due to a limited number of studies. Hence more research is necessary.

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth and pregnancy rates in subfertile women with anovulatory polycystic ovary syndrome, compared to clomiphene citrate. There is high-quality evidence that OHSS rates are similar with letrozole or clomiphene citrate. There is high-quality evidence of no difference in miscarriage rates or multiple pregnancy rates. There is low-quality evidence of no difference in live birth and pregnancy rates between letrozole and laparoscopic ovarian drilling, although there were few relevant studies. For the 2018 update, we added good-quality trials, upgrading the quality of the evidence.

Letrozole versus clomiphene citrate in polycystic ovary syndrome: a meta-analysis of randomized controlled trials

PURPOSE

Polycystic ovary syndrome (PCOS) is a common endocrine disturbance affecting women in the reproductive age group. The present study aimed to compare the effects of letrozole (LE) and clomiphene citrate (CC) for ovulation induction in women with PCOS.

METHODS

The PUBMED, Web of Science, and EMBASE databases were screened systematically for randomized controlled trials (RCTs) published from database inception to July 2017.

RESULTS

Eleven RCTs involving 2255 patients were included, and data were independently extracted and analyzed using 95% risk ratios (RRs) and confidence intervals (CIs) based on a random- or fixed-effect model (as appropriate). Meta-analyses of nine RCTs comparing LE and CC ovulation induction, followed by timed intercourse, indicated that the former significantly increased the ovulation rate (RR = 1.18; 95% CI 1.03-1.36, P = 0.01), pregnancy rate (RR = 1.34; 95% CI 1.09-1.64, P = 0.006), and live birth rate (RR = 1.55; 95% CI 1.28-1.88, P < 0.00001). However, LE and CC did not differ significantly in terms of the multiple pregnancy and abortion rates. Furthermore, LE for ovulation induction significantly improved the pregnancy rate after IUI.

CONCLUSION

LE is superior to CC for ovulation induction in patients with PCOS.

Effect of clomiphene citrate on endometrial thickness, ovulation, pregnancy and live birth in anovulatory women: systematic review and meta-analysis

OBJECTIVES

To compare the impact of clomiphene citrate (CC) vs other drug regimens on mid-cycle endometrial thickness (EMT), ovulation, pregnancy and live birth rates in women with World Health Organization (WHO) group II ovulatory disorders.

METHODS

We searched MEDLINE, EMBASE, Scopus, Web of Science, The Cochrane Central Register of Clinical Trials (CENTRAL) and the non-MEDLINE subset of PubMed from inception to December 2016 and cross-checked references of relevant articles. We included only randomized controlled trials (RCTs) comparing CC used alone vs other drug regimens for ovulation induction in women with WHO group II anovulation. Outcomes were mid-cycle EMT, ovulation, pregnancy and live birth rates. We pooled weighted mean differences (WMD) with 95% confidence intervals (CI) for continuous variables (EMT) and risk ratios (RR) with 95% CI for binary variables (ovulation, pregnancy and live birth rates).

RESULTS

We retrieved 1718 articles of which 33 RCTs (4349 women, 7210 ovulation induction cycles) were included. In 15 RCTs that compared CC with letrozole, EMT was lower in the CC group (1957 women, 3892 cycles; WMD, -1.39; 95% CI, -2.27 to -0.51; I²  = 100%), ovulation rates after CC and letrozole were comparable (1710 women, 3217 cycles; RR, 0.97; 95% CI, 0.90-1.04; I²  = 47%), while CC led to a lower pregnancy rate (1957 women, 3892 cycles; RR, 0.78; 95% CI, 0.63-0.95; I²  = 43%) and a lower live birth rate (RR, 0.70; 95% CI, 0.49-0.98; I²  = 35%). In two RCTs that compared CC with CC plus metformin, EMT, ovulation and pregnancy rates were comparable (101 women, 140 cycles; WMD, -0.23; 95% CI, -0.92 to 0.45; I²  = 78%; RR, 0.84; 95% CI, 0.67-1.06; I²  = 0%; and RR, 0.79; 95% CI, 0.33-1.87; I²  = 0%). In three studies that compared CC with CC plus N-acetyl cysteine (NAC), EMT was lower in the CC group (340 women, 300 cycles; WMD, -1.51; 95% CI, -1.98 to -1.04; I²  = 45%). In two studies that compared CC with CC + nitric oxide (NO) donor, EMT was lower in the CC group (120 women, 304 cycles; WMD, -1.75; 95% CI, -2.08 to -1.41; I²  = 0%). Compared with CC plus NO donor or NAC, CC showed statistically significant lower ovulation and pregnancy rates. Compared with tamoxifen in three studies, CC showed a tendency towards lower EMT (571 women, 844 cycles; WMD, -1.34; 95% CI, -2.70 to 0.01; I²  = 96%) with comparable ovulation and pregnancy rates.

CONCLUSIONS

In women with WHO group II ovulatory disorders, ovulation induction with CC might result in lower EMT than other ovulation induction regimens. Whether the lower EMT caused the lower pregnancy and live birth rates remains to be elucidated. Letrozole seems to be beneficial for these women. However, our findings should be interpreted with caution as the quality of evidence was very low. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Comparison of clomiphene citrate and letrozole for ovulation induction in women with polycystic ovary syndrome: a prospective randomized trial

To compare the therapeutic efficacy of clomiphene citrate (CC) and letrozole (LE) on ovulation, pregnancy, and live birth in women with polycystic ovary syndrome (PCOS); and to ensure if LE can replace CC as the first-line therapy for ovulation induction in these women. This is a prospectively, randomized, controlled trial in the tertiary hospital. Two-hundred and sixty-eight anovulatory PCOS patients were treated by CC or CC plus metformin and LE or LE plus metformin for three continuous cycles or conception; their ovulation rates, pregnancy rates, and live birth rates were calculated and compared. No significant difference was noted among the four groups regarding to the baseline data of clinical manifestations, serum sex hormone levels, and serum insulin levels. A total of 240 patients completed the therapies. The ovulation rate was significantly higher in the group LE than the group CC; however, no significant difference was noted between the groups LE and CC, CC, and CC + MET, or LE and LE + MET in the pregnancy rate, abortion rate, and live birth rate. No birth defect was found in the total of 63 newborns. CC regimen was still recommended to be the first-line therapy of ovulation induction for PCOS.

ANP promotes proliferation and inhibits apoptosis of ovarian granulosa cells by NPRA/PGRMC1/EGFR complex and improves ovary functions of PCOS rats

Polycystic ovary syndrome (PCOS) is a complicated reproductive endocrine disease characterized by polycystic ovaries, hyperandrogenism and anovulation. It is one of the main causes of infertility. RU486 is an antagonist of progesterone receptor, and most commonly used as a contraceptive. However, whether RU486 is correlated with PCOS remains unclear. Atrial natriuretic peptide (ANP) is a small peptide with natriuretic and diuretic functions, and its availability to be used in PCOS treatment is unknown. Here, we showed that the serum ANP level was lower in PCOS patients than that in healthy women, and it was also decreased in the serum and ovarian tissues of RU486-induced PCOS rats compared with the control rats. We also found that RU486 inhibited the proliferation and promoted the apoptosis of human KGN ovarian granulosa cells by downregulating progesterone receptor membrane component 1 (PGRMC1). Meantime, ANP promoted the proliferation and inhibited the apoptosis of KGN cells through upregulating ANP receptor A (NPRA). The promotive effects of ANP on ovarian functions were mediated through the formation of an NPRA/PGRMC1/EGFR complex, which further activated MAPK/ERK signaling and transcription factor AP1. Moreover, ANP treatment reversed the PCOS symptoms, and improved the fertility of RU486-induced PCOS rats. Collectively, these findings highlight that RU486 is associated with the pathogenesis of PCOS, and ANP treatment may be a promising therapeutic option for PCOS.

Neuroendocrine androgen action is a key extraovarian mediator in the development of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex hormonal disorder characterized by reproductive, endocrine, and metabolic abnormalities. As the origins of PCOS remain unknown, mechanism-based treatments are not feasible and current management relies on treatment of symptoms. Hyperandrogenism is the most consistent PCOS characteristic; however, it is unclear whether androgen excess, which is treatable, is a cause or a consequence of PCOS. As androgens mediate their actions via the androgen receptor (AR), we combined a mouse model of dihydrotestosterone (DHT)-induced PCOS with global and cell-specific AR-resistant (ARKO) mice to investigate the locus of androgen actions that mediate the development of the PCOS phenotype. Global loss of the AR reveals that AR signaling is required for all DHT-induced features of PCOS. Neuron-specific AR signaling was required for the development of dysfunctional ovulation, classic polycystic ovaries, reduced large antral follicle health, and several metabolic traits including obesity and dyslipidemia. In addition, ovariectomized ARKO hosts with wild-type ovary transplants displayed normal estrous cycles and corpora lutea, despite DHT treatment, implying extraovarian and not intraovarian AR actions are key loci of androgen action in generating the PCOS phenotype. These findings provide strong evidence that neuroendocrine genomic AR signaling is an important extraovarian mediator in the development of PCOS traits. Thus, targeting AR-driven mechanisms that initiate PCOS is a promising strategy for the development of novel treatments for PCOS.

Treatment strategies for women with WHO group II anovulation: systematic review and network meta-analysis

OBJECTIVE

To compare the effectiveness of alternative first line treatment options for women with WHO group II anovulation wishing to conceive.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Cochrane Central Register of Controlled Trials, Medline, and Embase, up to 11 April 2016.

STUDY SELECTION

Randomised controlled trials comparing eight ovulation induction treatments in women with WHO group II anovulation: clomiphene, letrozole, metformin, clomiphene and metformin combined, tamoxifen, gonadotropins, laparoscopic ovarian drilling, and placebo or no treatment. Study quality was measured on the basis of the methodology and categories described in the Cochrane Collaboration Handbook. Pregnancy, defined preferably as clinical pregnancy, was the primary outcome; live birth, ovulation, miscarriage, and multiple pregnancy were secondary outcomes.

RESULTS

Of 2631 titles and abstracts initially identified, 54 trials reporting on 7173 women were included. All pharmacological treatments were superior to placebo or no intervention in terms of pregnancy and ovulation. Compared with clomiphene alone, both letrozole and the combination of clomiphene and metformin showed higher pregnancy rates (odds ratio 1.69, 95% confidence interval 1.33 to 2.14; 1.71, 1.28 to 2.27; respectively). Letrozole led to higher live birth rates when compared with clomiphene alone (1.67, 1.11 to 2.49). Metformin led to lower multiple pregnancy rates compared with clomiphene alone (0.22, 0.05 to 0.93).

CONCLUSIONS

In women with WHO group II anovulation, letrozole and the combination of clomiphene and metformin are superior to clomiphene alone in terms of pregnancy. Compared with clomiphene alone, letrozole is the only treatment showing a significantly higher rate of live birth.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015027579.

READERS' NOTE

This is the second version of this paper. The original version was corrected following the retraction of two studies and removal of another which were ineligible (references 40, 41, and 75 of the original paper). These studies are not shown in this version. A tracked changes version of the original version is attached as a supplementary file to the correction notice, which explains the issue further.

Cost effectiveness of letrozole and purified urinary FSH in treating women with clomiphene citrate-resistant polycystic ovarian syndrome: a randomized controlled trial

We aimed to compare the cost effectiveness of letrozole versus purified urinary follicle stimulating hormone (FSH) in treating patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). This was a randomized trial conducted in Cairo University and Beni-Suef University Hospitals, Egypt. A cohort of 140 eligible women was randomized to receive either letrozole 2.5 mg twice daily for five days, or FSH using a graduated regimen starting with a dose of 75 IU. Treatment was repeated for three months if pregnancy did not occur. There were no significant differences between the two treatments in the cumulative clinical pregnancy rate (30% vs. 34%; p = 0.578), cumulative ovulation rate (47% vs. 57%; p = 0.236), miscarriage rate (9% vs. 4%, p > 0.999) or multiple pregnancy rate (0% and 8%, p = 0.491) but the FSH cycles were 4.8 times more expensive. Letrozole and FSH were both effective in treating women with CC-resistant PCOS but letrozole was more cost effective.Study registration number: NCT02304107.

Comparison of the Effect of Clomiphene- Estradiol Valerate vs Letrozole on Endometrial Thickness, Abortion and Pregnancy Rate in Infertile Women with Polycystic Ovarian Syndrome

INTRODUCTION

Clomiphene citrate is the first-line therapy for ovulation induction in Polycystic Ovarian Syndrome (PCOS). This drug binds and blocks estrogen receptors and thought to have an anti estrogenic effect on endometrium volume, thus may have adverse effect on fertility.

AIM

This study aimed to compare the effect of Clomiphene citrate plus Estradiol Valerate with Letrozole on endometrial thickness, abortion and pregnancy rate in infertile women with PCOS undergoing ovulation induction.

MATERIALS AND METHODS

This was a randomized double blind clinical trial study on 100 women with PCOS, with an endometrial thickness less than 7mm in spite of follicles greater than 18mm after administration of Clomiphene citrate 100mg/d from 3(th) to 7(th) day of menstruation. They were randomly divided in two groups. Group A received 100mg Clomiphene citrate from day 3 to day 7 of menstruation and 4 mg Estradiol Valerate after the 8(th) day of menstruation until 14(th) day. Group B treated by 5mg Letrozole from day 3 to 7 of menstruation with placebo from 8(th) to 14(th) day of menstruation. In both groups endometrial thickness was measured by transvaginal sonography in the 14(th) day of menstruation. Data were analysed using SPSS Ver.18.0.

RESULTS

The mean age was 30.34 years in group A and 29.62 years in group B (p=0.381). The number of infertility years in group A was 3.73 years and in group B was 3.85 years. There was no significant relationship statistically between the two groups in terms of mean age and infertility years (p=0.99). Endometrial thickness in group A was 7.26mm and in group B was 8.17 mm. Pregnancy rates in group A and group B was 32% and 16% respectively. There was significant relationship statistically between the two groups in terms of endometrial thickness and pregnancy rates (p=0.021 and p=0.05). There was no abortion in group A and 5 cases had abortion in group B, there was a significant relationship between the two groups statistically (p=0.028).

CONCLUSION

Letrozole increased endometrial thickness and pregnancy rate in infertile women, therefore its administration is recommended.

Follicular hyperandrogenism downregulates aromatase in luteinized granulosa cells in polycystic ovary syndrome women

Women with polycystic ovary syndrome (PCOS) undergoing IVF–embryo transfer based-assisted reproductive technology (ART) treatment show variable ovarian responses to exogenous FSH administration. For better understanding and control of PCOS ovarian responses in ART, the present study was carried out to compare the follicular hormones and the expression of granulosa cell genes between PCOS and non-PCOS women during ART treatment as well as their IVF outcomes. Overall, 138 PCOS and 78 non-PCOS women were recruited for the present study. Follicular fluid collected from PCOS women showed high levels of testosterone. The expression of aromatase was found significantly reduced in luteinized granulosa cells from PCOS women. In cultured luteinized granulosa cells isolated from non-PCOS women, their exposure to testosterone at a level that was observed in PCOS follicles could decrease both mRNA and protein levels of aromatase in vitro. The inhibitory effect of testosterone was abolished by androgen receptor antagonist, flutamide. These results suggest that the hyperandrogenic follicular environment may be a key hazardous factor leading to the down-regulation of aromatase in PCOS.

Letrozole versus clomiphene citrate in polycystic ovary syndrome: systematic review and meta-analysis

The objective of the present systematic review and meta-analysis was to examine the literature and to identify the results of randomized controlled trials (RCTs) comparing the use of letrozole to clomiphene citrate (CC) for ovulation induction in patients with polycystic ovary syndrome (PCOS). An exhaustive electronic literature search was performed using the MEDLINE and EMBASE databases until October 2014. Seven prospective RCTs comparing the use of letrozole to CC in PCOS patients met the inclusion criteria. Overall, the seven included studies accounted for 1833 patients (906 in the letrozole group and 927 in the CC group) and for 4999 ovulation induction cycles (2455 in the letrozole group and 2544 in the CC group). Five of the included studies reported data on live birth rates. There was a statistically significant increase in the live birth and pregnancy rates in the letrozole group when compared to the CC group, with a relative risk (RR) = 1.55 (95% confidence interval (CI): 1.26-1.90; I(2) = 0%) and RR = 1.38 (95% CI: 1.05-1.83; I(2) = 61%), respectively. There were no differences in the multiple pregnancy, miscarriage and ovulation rates between the two groups. Our study found that letrozole is superior to CC when considering the live birth and pregnancy rates in patients with PCOS.

The management of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women. The syndrome is typified by its heterogeneous presentation, which includes hirsutism (a function of hypersecretion of ovarian androgens), menstrual irregularity and infertility (that is due to infrequent or absent ovulation). Furthermore, PCOS predisposes patients to metabolic dysfunction and an increased risk of type 2 diabetes mellitus (T2DM). The aetiology of the syndrome has a major genetic component. Obesity exacerbates the insulin resistance that is a feature of PCOS in many women and amplifies the clinical and biochemical abnormalities. In clinical practice, the choice of investigations to be done depends mainly on the presenting symptoms. The approach to management is likewise dependent on the presenting complaint. Symptoms of androgen excess (hirsutism, acne and alopecia) require cosmetic measures, suppression of ovarian androgen function and anti-androgen therapy, alone or in combination. Ovulation rate is improved by diet and lifestyle intervention in overweight individuals but induction of ovulation by, in the first instance, anti-estrogens is usually required. Monitoring of glucose is important in overweight women and/or those with a family history of T2DM. Metformin is indicated for women with impaired glucose tolerance but whether this drug is otherwise useful in women with PCOS remains debatable.

A randomized trial comparing the ovulation induction efficacy of clomiphene citrate and letrozole

Background:

Letrazole is an aromatase inhibitor, which is useful in ovulation induction. However, evidence on its efficacy over clomiphene citrate, which is the first of drug used for therapy of anovulation, is insufficient in Indian patients.

Aims:

To compare the efficacy of letrozole and clomiphene citrate in attaining optimal follicular growth.

Materials and Methods:

The study was conducted in the infertility clinic of Mahatma Gandhi Medical College and Research Institute, Pondicherry, India from June 2008 to December 2009. Fifty women with ovulatory dysfunction as a cause of infertility were enrolled and randomized into two groups of 25 each. Group 1 received clomiphene citrate in incremental dose from 50 mg up to150 mg and Group 2 patient received letrozole in incremental dose from 2.5 mg to 7.5 mg, depending upon the ovulation response. In both the groups, number of follicles, diameter of large follicle, endometrial thickness, and serum estradiol and pregnancy rate were compared. The data from both groups are represented as mean and standard deviation and statistically compared using Student's t test.

Results:

The number of follicles (1.89 ± 0.9 vs 1.18 ± 0.393) and serum estradiol levels (437.5 ± 293.7 pg/mL vs 291.82 ± 59.86 pg/mL) were higher in Group 1, while follicular diameter (20.67 ± 0.970 mm vs. 20.76 ± 0.903 mm) and endometrial thickness (8.5 mm vs.7.4 mm) were similar in both the Groups.

Conclusions:

Although letrozole is used for ovulation induction in anovulatory infertility, no significant beneficial effects of letrozole compared to use of clomiphene citratewere observedin ourstudy. Hence, we concur with the use of clomiphene citrate as the first line of drug for ovulation induction in Indian population and warrant larger size studiesto further validate our results.

Aromatase inhibitors for subfertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a novel class of drugs that were introduced for ovulation induction in 2001. Over the last ten years clinical trials have reached differing conclusions as to whether the AI letrozole is at least as effective as the first-line treatment clomiphene citrate (CC).

OBJECTIVES

To evaluate the effectiveness and safety of aromatase inhibitors for subfertile women with anovulatory PCOS.

SEARCH METHODS

We searched the following sources from inception to 24/10/2013 to identify relevant randomised controlled trials (RCTs): the Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO, Pubmed, LILACS, Web of Knowledge, the World Health Organisation (WHO) clinical trials register and Clinicaltrials.gov. Furthermore, we manually searched the references of relevant articles.The search was not restricted by language or publication status.

SELECTION CRITERIA

We included all RCTs of aromatase inhibitors used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed trial quality. Studies were pooled where appropriate using a fixed effect model to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth and OHSS. Secondary outcomes were pregnancy, miscarriage and multiple pregnancy. The quality of the evidence for each comparison was assessed using GRADE methods.

MAIN RESULTS

We included 26 RCTs (5560 women). In all studies the aromatase inhibitor was letrozole. Live birth (12 RCTs) One RCT compared letrozole with placebo in women who were clomiphene resistant and the results were inconclusive (OR 3.17, 95% CI 0.12 to 83.17, n=36)Nine RCTs compared letrozole with clomiphene citrate (with or without adjuncts) followed by timed intercourse. The birth rate was higher in the letrozole group (OR 1.63, 95% CI 1.31 to 2.03, n=1783, I²=3%)Two RCTs compared letrozole with laparoscopic ovarian drilling. There was no evidence of a difference between the groups in live birth rate (OR 1.19, 95% CI 0.76 to 1.86, n=407, I²=0%) OHSS (16 RCTs) There was no evidence of a difference in OHSS rates when letrozole was compared with placebo (one RCT, n=36), clomiphene citrate (with or without adjuncts) followed by timed intercourse (nine RCTs, n=2179), clomiphene citrate (with or without adjuncts) followed by intrauterine insemination (IUI) (two RCTs, n=1494), laparoscopic ovarian drilling (one RCT, n=260) or anastrozole (one RCT, n=220). Events were absent or very rare, and no study had more than 2 cases of OHSS. Clinical pregnancy (25 RCTs) One RCT compared letrozole versus placebo in women who were clomiphene resistant and the results were inconclusive (OR 3.17, 95% CI 0.12 to 83.17, n=36)Fourteen RCTs compared letrozole versus clomiphene citrate (with or without adjuncts) followed by timed intercourse. The pregnancy rate was higher in the letrozole group (OR 1.32, 95% CI 1.09 to 1.60, n=2066, I²=25%)Three RCTs compared letrozole versus clomiphene citrate (with or without adjuncts) followed by IUI. The pregnancy rate was higher in the letrozole group (OR 1.71, 95% CI 1.30 to 2.25, n=1597)Three RCTs compared letrozole versus laparoscopic ovarian drilling. There was no evidence of a difference in the clinical pregnancy rate (OR 1.14, 95% CI 0.80 to 1.65, n=553, I²=0%)Two RCTs compared letrozole versus anastrozole, one RCT compared a five day versus a 10 day administration protocol for letrozole and another RCT compared 5 mg of letrozole versus 7.5 mg of letrozole. There was no evidence of a difference in the clinical pregnancy rate in these comparisons.The quality of the evidence was rated as low for live birth and pregnancy outcomes. The reasons for downgrading the evidence were poor reporting of study methods, possible publication bias and the tendency for studies that reported live birth to report higher clinical pregnancy rates in the letrozole group than studies that failed to report live birth (suggesting that results might be somewhat less favourable to letrozole if all studies reported live birth).

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth and pregnancy rates in subfertile women with anovulatory PCOS, compared to clomiphene citrate. The quality of this evidence is low and findings should be regarded with some caution. There appears to be no difference in effectiveness between letrozole and laparoscopic ovarian drilling, though there were few relevant studies. OHSS was a very rare event, with no occurrences in most studies.

A pilot study to prevent a thin endometrium in patients undergoing clomiphene citrate treatment

BACKGROUND

Clomiphene citrate (CC) is most commonly used as a first-line treatment of infertility. However, a disturbance of endometrial growth by the adverse effects of the CC has been recognized. Since a thin endometrium is recognized as a critical factor of implantation failure, preventing CC-induced thinning of the endometrium is important. This study was undertaken to investigate whether the modified CC treatments are useful to prevent a thin endometrium in patients undergoing CC treatments.

METHODS

This study is a prospective, randomized controlled study. The study was performed at the Saiseikai Shimonoseki General Hospital during a 4-month period (May 2012 to September 2012). Sixty-six infertile women who had a thin endometrium (< 8 mm) during the standard CC treatment (50 mg/day on days 5-9 of the menstrual cycle) were enrolled. The patients were randomly divided into three groups: 22 patients were given 25 mg/day CC on days 5-9 (half-dose group), 22 patients were given 50 mg/day CC on days 1-5 (early administration group) and 22 patients received a standard CC treatment again (control group). Endometrial thickness at the induction of ovulation was assessed by ultrasonography. The primary endpoint of this study was an endometrial thickness.

RESULTS

Half dose administration and early administration improved the endometrial thickness (≥ 8 mm) in 14 patients (70%) and in 19 patients (90%) respectively, while only 3 patients (15%) improved in endometrial thickness in the control group. The mean endometrial thickness was also significantly higher in the half dose group (8.6 ± 1.5 mm) and early administration group (9.4 ± 1.5 mm) compared to the control group (6.7 ± 1.8 mm). No side effect was observed in this study.

CONCLUSIONS

The modified treatment with a half-dose or early administration of CC significantly increased endometrial thickness in patients with a history of thin endometrium caused by the standard CC regimen. The modified CC treatments in this study can be beneficial for patients with a thin endometrium as a result of standard CC treatment.

TRIAL REGISTRATION

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000007959.

Epidemiology, diagnosis, and management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common heterogeneous endocrine disorder characterized by irregular menses, hyperandrogenism, and polycystic ovaries. The prevalence of PCOS varies depending on which criteria are used to make the diagnosis, but is as high as 15%–20% when the European Society for Human Reproduction and Embryology/American Society for Reproductive Medicine criteria are used. Clinical manifestations include oligomenorrhea or amenorrhea, hirsutism, and frequently infertility. Risk factors for PCOS in adults includes type 1 diabetes, type 2 diabetes, and gestational diabetes. Insulin resistance affects 50%–70% of women with PCOS leading to a number of comorbidities including metabolic syndrome, hypertension, dyslipidemia, glucose intolerance, and diabetes. Studies show that women with PCOS are more likely to have increased coronary artery calcium scores and increased carotid intima-media thickness. Mental health disorders including depression, anxiety, bipolar disorder and binge eating disorder also occur more frequently in women with PCOS. Weight loss improves menstrual irregularities, symptoms of androgen excess, and infertility. Management of clinical manifestations of PCOS includes oral contraceptives for menstrual irregularities and hirsutism. Spironolactone and finasteride are used to treat symptoms of androgen excess. Treatment options for infertility include clomiphene, laparoscopic ovarian drilling, gonadotropins, and assisted reproductive technology. Recent data suggest that letrozole and metformin may play an important role in ovulation induction. Proper diagnosis and management of PCOS is essential to address patient concerns but also to prevent future metabolic, endocrine, psychiatric, and cardiovascular complications.