Letrozole versus clomiphene citrate for ovulation induction in anovulatory women with polycystic ovarian syndrome: A randomized controlled trial

Is combined letrozole and clomiphene superior to either as monotherapy: a systemic review and meta-analysis based on clinical trials

OBJECTIVE

This research was conducted to assess the therapeutic advantage of combined letrozole and clomiphene citrate versus monotherapy for polycystic ovarian syndrome (PCOS) patients.

STUDY DESIGN

Five databases were searched using the search string: (letrozole and clomiphene) AND (clomiphene OR clomiphene citrate OR CC) AND (letrozole OR LE) AND (ovulation induc* OR fertility induc* OR fertility preserv*) AND (polycystic ovarian syndrome OR PCOS). All statistical analyses were conducted in Review Manager 5.4.1. Random effect-effect model was used to pool risk ratio (RR), mean difference (MD), and odds ratio (OR) and their corresponding 95% confidence interval (CI). Moreover, qualitative analysis was conducted to qualitatively analyze ovulation, secondary outcomes, and cycle characteristics.

RESULTS

One clinical trial and three randomized clinical trials (RCTs) were used in the study. Two studies were used in a quantitative analysis showing that combination was superior for ovulation induction (RR = 1.86 [1.37, 2.53]; p < 0.0001; I2 = 0%), but the number of follicles ≥15 mm was significantly associated with the combination (MD = 0.40[0.14, 0.66]; p = 0.002; I2 = 0%). On subgroup analysis, only hot flushes were significantly associated with the combination (RR = 2.67[1.12, 6.36]; p = 0.03; I2 = 0%). The meta-analysis of two studies reported a significantly higher ovulation rate and number of dominant follicles in the combination therapy group compared with the LE alone arm but no significant difference in pregnancy rate, endometrial thickness, and adverse events.

CONCLUSION

Our study demonstrates a significant effect of the combination on ovulation induction. The combination yielded a better chance of conception and viable pregnancy. Further studies are needed to determine the live birth rate. HighlightsCombined Letrozole and Clomiphene is superior to either of these drugs alone for ovulation induction in PCOS.Our results conclude that the combination results in better ovulation, cycle characteristics, and secondary changes.Only the incidence of hot flushes as an adverse effect is increasingly reported in combination.

New insights into the ovulatory process in the human ovary

BACKGROUND

Successful ovulation is essential for natural conception and fertility. Defects in the ovulatory process are associated with various conditions of infertility or subfertility in women. However, our understanding of the intra-ovarian biochemical mechanisms underlying this process in women has lagged compared to our understanding of animal models. This has been largely due to the limited availability of human ovarian samples that can be used to examine changes across the ovulatory period and delineate the underlying cellular/molecular mechanisms in women. Despite this challenge, steady progress has been made to improve our knowledge of the ovulatory process in women by: (i) collecting granulosa cells across the IVF interval, (ii) creating a novel approach to collecting follicular cells and tissues across the periovulatory period from normally cycling women, and (iii) developing unique in vitro models to examine the LH surge or hCG administration-induced ovulatory changes in gene expression, the regulatory mechanisms underlying the ovulatory changes, and the specific functions of the ovulatory factors.

OBJECTIVE AND RATIONALE

The objective of this review is to summarize findings generated using in vivo and in vitro models of human ovulation, with the goal of providing new insights into the mechanisms underlying the ovulatory process in women.

SEARCH METHODS

This review is based on the authors' own studies and a search of the relevant literature on human ovulation to date using PubMed search terms such as 'human ovulation EGF-signaling', 'human ovulation steroidogenesis', 'human ovulation transcription factor', 'human ovulation prostaglandin', 'human ovulation proteinase', 'human ovulation angiogenesis' 'human ovulation chemokine', 'human ovulatory disorder', 'human granulosa cell culture'. Our approach includes comparing the data from the authors' studies with the existing microarray or RNA-seq datasets generated using ovarian cells obtained throughout the ovulatory period from humans, monkeys, and mice.

OUTCOMES

Current findings from studies using in vivo and in vitro models demonstrate that the LH surge or hCG administration increases the expression of ovulatory mediators, including EGF-like factors, steroids, transcription factors, prostaglandins, proteolytic systems, and other autocrine and paracrine factors, similar to those observed in other animal models such as rodents, ruminants, and monkeys. However, the specific ovulatory factors induced, their expression pattern, and their regulatory mechanisms vary among different species. These species-specific differences stress the necessity of utilizing human samples to delineate the mechanisms underlying the ovulatory process in women.

WIDER IMPLICATIONS

The data from human ovulation in vivo and in vitro models have begun to fill the gaps in our understanding of the ovulatory process in women. Further efforts are needed to discover novel ovulatory factors. One approach to address these gaps is to improve existing in vitro models to more closely mimic in vivo ovulatory conditions in humans. This is critically important as the knowledge obtained from these human studies can be translated directly to aid in the diagnosis of ovulation-associated pathological conditions, for the development of more effective treatment to help women with anovulatory infertility or, conversely, to better manage ovulation for contraceptive purposes.

REGISTRATION NUMBER

N/A.

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.

The Effect of Baseline Ovarian Cyst on Pregnancy Outcomes in Ovulation Induction/Intrauterine Insemination Cycles

Objective

To determine the effects of a baseline ovarian cyst on ovulation induction/intrauterine insemination (OI/IUI) cycle outcomes.

Methods

A retrospective cohort analysis of 270 patients and 461 OI/IUI cycles performed between 2011 and 2021 was performed. The exposure variable was a simple appearing ovarian cyst diagnosed at baseline ultrasound measuring ≥10 mm with an estradiol level <75 ng/mL. The primary outcome analyzed was an ultrasound-confirmed intrauterine pregnancy. Secondary outcomes included positive pregnancy test and live birth. Summary data were presented with percentages, mean (standard deviation), or median (interquartile range). Comparisons of dichotomous variables were performed with the chi-square test, and continuous variables were compared using t-test. Regression analysis was performed using a general linear model. p-Values <0.05 were considered statistically significant.

Results

The clinical pregnancy rate was nominally higher in the group without a cyst present at baseline ultrasound compared with those cycles with a simple cyst present, but the difference was not statistically significant (45/300 [15%] vs. 15/161 [9.3%], risk ratio [RR] 0.63 [0.36, 1.1]). After adjusting for BMI ≥30 and age ≥35, there remained no significant difference in clinical pregnancy rate (adjusted RR 0.65 [0.37, 1.1]).

Conclusion

Given the present data, it is reasonable to proceed with IUI in the case of a baseline simple ovarian cyst. However, this finding may have an impact on clinical pregnancy outcomes in OI/IUI, and further research on the topic is warranted. Although this study was underpowered with fewer cycles than needed to demonstrate a significant difference, the point estimate suggests that the difference in clinical pregnancy rate could be ∼35%.

Sequential 2.5 mg letrozole/FSH therapy is more effective for promoting pregnancy in infertile women with PCOS: a pragmatic randomized controlled trial

Study question

In infertile women with polycystic ovary syndrome (PCOS), is the sequential use of letrozole 2.5 mg/follicle stimulating hormone(FSH) more effective than letrozole 5 mg/FSH in stimulating ovulation and promoting pregnancy?

Research design and methods

The study was designed as a prospective, single-center, randomized, controlled pragmatic clinical trial. 220 infertile women between the ages of 20 and 40, who matched the Rotterdam criteria for PCOS and had no other identified reasons for infertility were enrolled from April 2023 to July 2023.The participants were randomly assigned to two groups in a 1:1 ratio. One group received 2.5 mg of letrozole on cycle days 3-7 with a sequential injection of 75 IU FSH on cycle days 8-10 (n = 110), while the other group received 5 mg of letrozole on cycle days 3-7 with a sequential injection of 75 IU FSH on cycle days 8-10 (n = 110). The duration of FSH treatment varied depending on the follicular development stage. Each participant underwent one to three treatment cycles until achieving pregnancy.The primary outcome was the cumulative pregnancy rate of all the participants. Secondary outcomes included characteristics and clinical pregnancy rates of all the intervention cycles.

Results

For all 220 participants, the sequential letrozole 2.5 mg/FSH treatment group had a significantly higher cumulative pregnancy rate compared to the letrozole 5 mg/FSH treatment group (72.7% versus 59.1%, RR (95%CI) = 1.23 (1.02, 1.49), P-value = 0.033). For all 468 intervention cycles, letrozole 2.5 mg/FSH group had a significantly higher clinical pregnancy rate than the letrozole 5 mg/FSH group (36.2% versus 26.3%, P-value = 0.021), no statistically significant differences were observed in ovulation rates or adverse effects.

Conclusions

The data indicate that the sequential letrozole 2.5mg/FSH protocol may be more effective than the sequential letrozole 5mg/FSH protocol for promoting pregnancy in infertile women with PCOS.

Clinical trial registration

www.chictr.org.cn, identifier ChiCTR2300069638.

In praise of ovulation induction for the management of anovulatory subfertility

Rapid advances in assisted reproductive technology have revolutionized fertility treatments for couples worldwide seeking a pregnancy. Although this is promising, concerns are emerging over the overuse of unnecessary assisted conception treatments, particularly among couples with anovulatory subfertility. Some experts are calling for the cessation of ovulation induction as the primary treatment of anovulatory subfertility in favour of more sophisticated assisted conception treatments. In the absence of other causes of subfertility, ovulation induction in patients with type 1 and type 2 anovulation disorders can achieve an up to 80% ovulation rate with a 40% cumulative pregnancy rate and few adverse effects. Considering the various risks and high costs associated with assisted reproductive technology treatments, it is hard to argue for their cost-effectiveness when simpler, safer and cheaper pharmacological ovulation induction could achieve comparable pregnancy rates. We argue here for the safe, effective and ethical use of ovulation induction in this population, supplemented by a judicious use of assisted conception treatments. We emphasize the essential role of ovulation induction as a first-line intervention for couples with anovulatory subfertility delivered within a patient-centred multidisciplinary care model and with a clear escalation pathway to use assisted reproductive technology treatments based on the person's response, characteristics and treatment preference.

Impact of Oral Ovulatory Induction Medications Among Female Military Members and Military Beneficiaries

INTRODUCTION

Twelve percent of reproductive aged females in the United States have utilized fertility services, and it is estimated that 25% of infertility patients have ovulatory dysfunction. Clomiphene and letrozole are currently first-line treatment options for ovulatory dysfunction. These are both disqualifying medications in the U.S. Navy and Air Force for duties that involve flying. These medication restrictions could reduce the likelihood of female aviators seeking infertility treatment. This pilot study seeks to evaluate the severity of common side effects in order to provide recommendations to the current aeromedical guidelines.

MATERIALS AND METHODS

An anonymous survey was provided to all active duty and dependent patients who presented to the infertility clinic at a single military medical center for a mid-cycle scan from February 2021 to February 2022. The survey included demographic, treatment cycle, medication type, medication dose, and the presence and severity of common adverse reactions. The provider additionally recorded the number of dominant follicles that were noted at the time of ultrasound. The Kruskal-Wallis test was used to analyze the severity of adverse effects, and chi-square analysis was used to compare the difference in symptoms from previous cycles.

RESULTS

A total of 569 surveys were collected. Of the participants, 45.4% were military members and 3.5% worked in the field of aviation. Letrozole was prescribed to 88.7% of the patients. Less than 3% reported severe or debilitating side effects. There was no difference in presence or severity when comparing the cycle number.

CONCLUSIONS

The majority of side effects for oral ovulation induction medications were described as slight or mild. Therefore, this study provides evidence-based data of severity side effects that could be used to guide the waiver process and improve readiness for female aviators in the military.

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.

Transvaginal needle versus laparoscopic ovarian drilling in hormonal profile and pregnancy outcomes of polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder distinguished by a persistent absence of ovulation. Ovarian drilling is a recognized therapeutic approach for PCOS patients who are unresponsive to medication and can be performed through invasive laparoscopic access or less-invasive transvaginal access. The aim of this systematic review and meta-analysis was to assess the efficacy of transvaginal ultrasound -guided ovarian needle drilling with conventional laparoscopic ovarian drilling (LOD) in patients with PCOS.

METHODS

PUBMED, Scopus, and Cochrane databases were systematically searched for eligible randomized controlled trials (RCTs) from articles published from inception to January 2023. We include RCTs of PCOS that compared transvaginal ovarian drilling and LOD and reported on ovulation and pregnancy rates as the main outcome variable. We evaluated study quality using the Cochrane Risk of bias 2 tool. A random-effects meta-analysis was performed and the certainty of the evidence was assessed according to the GRADE approach. We registered the protocol prospectively in PROSPERO (CRD42023397481).

RESULTS

Six RCTs including 899 women with PCOS met the inclusion criteria. LOD was found to significantly reduce anti-Mullerian hormone (AMH) (SMD: -0.22; 95% CI: -0.38, -0.05; I² = 39.85%) and antral follicle count (AFC) (SMD: -1.22; 95% CI: -2.26, -0.19; I² = 97.55%) compared to transvaginal ovarian drilling. Our findings also indicated that LOD significantly increased the ovulation rate by 25% compared to transvaginal ovarian drilling (RR: 1.25; 95% CI: 1.02, 1.54; I2 = 64.58%). However, we found no significant difference between the two groups in terms of follicle stimulating hormone (SMD: 0.04; 95% CI: -0.26, 0.33; I2 = 61.53%), luteinizing hormone (SMD: -0.07; 95% CI: -0.90, 0.77; I2 = 94.92%), and pregnancy rate (RR: 1.37; 95% CI: 0.94, 1.98; I2 = 50.49%).

CONCLUSION

LOD significantly lowers circulating AMH and AFC and significantly increases ovulation rate in PCOS patients compared to transvaginal ovarian drilling. As transvaginal ovarian drillingremains a less-invasive, more cost-effective, and simpler alternative, further studies are warranted to compare these two techniques in large cohorts, with a particular focus on ovarian reserve and pregnancy outcomes.

Assessment of Fertility Outcomes Following Combined Clomiphene and Letrozole Versus Letrozole Therapy for the Treatment of Polycystic Ovarian Syndrome Subfertility

BACKGROUND

Poly Cystic Ovarian Syndrome (PCOS) affects 8-13% of women in their reproductive age and is one of the foremost causes of female subfertility. Traditionally, clomiphene citrate has been the first-line treatment for ovulation induction in PCOS. However, the European Society of Human Reproduction and Embryology (ESHRE) international evidence-based guidelines in 2018 recommended the use of letrozole as first-line therapy for ovulation induction in anovulatory PCOS women, due to better pregnancy and live birth rates. Here we aimed to evaluate the effect of combined - clomiphene and letrozole versus letrozole for the treatment of PCOS subfertility.

METHODS

It was a retrospective cohort study conducted on reproductive-age women fulfilling Rotterdam Criteria for PCOS with a history of subfertility. All participants receiving at least one cycle of letrozole and clomiphene combination were recruited as cases. However, women receiving letrozole only for ovulation induction were taken as controls. Hospital records were abstracted for data on baseline characteristics such as age, duration of infertility, PCOS phenotype, body mass index (BMI), past medical and fertility history, treatment with ovulation induction agents, and metformin use. The mean size of the largest follicle, number of dominant follicles of size greater than 15 mm and endometrial thickness on Days 12-14 or on the day of the luteinizing hormone (LH) surge were recorded. A cycle was termed ovulatory if serum progesterone levels were > 5.0 ng/ml on the seventh day after the LH surge or day 22 in the absence of the LH surge. Data pertaining to therapy-associated side effects were also abstracted from the clinical records.

RESULTS

Amongst the ovulatory cycles in both groups, there was no significant difference in the day of the LH surge. Serum progesterone levels on the seventh day post-ovulation were higher with combination therapy (19.35 v/s 26.71, p=0.004). The number of ovulatory cycles was also greater with combination therapy, but the difference was just short of significant (25 vs 18, p=0.08). The mean diameter of the largest follicle, incidence of multi-follicular ovulation, and thin endometrium were similar in both groups. The adverse effect profile was similar in both groups.

CONCLUSION

Combination treatment of clomiphene citrate with letrozole may potentially improve fertility outcomes in PCOS subfertility in terms of the likelihood of ovulation and higher post-ovulatory progesterone levels, however, larger studies are required.

The effects of first-line pharmacological treatments for reproductive outcomes in infertile women with PCOS: a systematic review and network meta-analysis

BACKGROUND

Polycystic ovarian syndrome (PCOS) is one of the most common causes of infertility in reproductive-age women. However, the efficacy and optimal therapeutic strategy for reproductive outcomes are still under debate. We conducted a systematic review and network meta-analysis to compare the efficacy of different first-line pharmacological therapies in terms of reproductive outcomes for women with PCOS and infertility.

METHODS

A systematic retrieval of databases was conducted, and randomized clinical trials (RCTs) of pharmacological interventions for infertile PCOS women were included. The primary outcomes were clinical pregnancy and live birth, and the secondary outcomes were miscarriage, ectopic pregnancy and multiple pregnancy. A network meta-analysis based on a Bayesian model was performed to compare the effects of the pharmacological strategies.

RESULTS

A total of 27 RCTs with 12 interventions were included, and all therapies tended to increase clinical pregnancy, especially pioglitazone (PIO) (log OR 3.14, 95% CI 1.56 ~ 4.70, moderate confidence), clomiphene citrate (CC) + exenatide (EXE) (2.96, 1.07 ~ 4.82, moderate confidence) and CC + metformin (MET) + PIO (2.82, 0.99 ~ 4.60, moderate confidence). Moreover, CC + MET + PIO (2.8, -0.25 ~ 6.06, very low confidence) could increase live birth most when compared to placebo, even without a significant difference. For secondary outcomes, PIO showed a tendency to increase miscarriage (1.44, -1.69 ~ 5.28, very low confidence). MET (-11.25, -33.7 ~ 0.57, low confidence) and LZ + MET (-10.44, -59.56 ~ 42.11, very low confidence) were beneficial for decreasing ectopic pregnancy. MET (0.07, -4.26 ~ 4.34, low confidence) showed a neutral effect in multiple pregnancy. Subgroup analysis demonstrated no significant difference between these medications and placebo in obese participants.

CONCLUSIONS

Most first-line pharmacological treatments were effective in improving clinical pregnancy. CC + MET + PIO should be recommended as the optimal therapeutic strategy to improve pregnancy outcomes. However, none of the above treatments had a beneficial effect on clinical pregnancy in obese PCOS.

TRIAL REGISTRATION

CRD42020183541; 05 July 2020.

The management of infertility for primary care physicians

To conduct this review of primary care, we looked for related papers in PubMed from the last 15 years. WHO's initial concept of Health defined a condition of physical, mental, and social well-being, nowadays extended to quality of life. Infertility or not being able to form a family fits perfectly into the definition. Primary care is responsible for mandatory discussions about fertility as part of a broader aspect regarding reproductive health issues. Having children is a decision taken by heterosexual couples, same sex couples, or single individuals. Understanding factors associated with infertility help guiding propedeutic. Although woman's age is one of the main factors to influence treatment success rates, multifactorial male factor may contribute to 50 percent. Infertility consultations should include partners, alleviating the accompanying stress and anxiety. Anamnesis must focus on duration of infertility, primary or secondary, sexual activity, and lifestyle habits such as smoking, alcohol consumption, diet, physical activity, use of licit and/or illicit drugs, and occupational risks. Previous treatments should be accessed. Management of infertility by primary care is mandatory, and patients requiring specialized treatments must not have their journey protracted. Strategies and couple-based interventions are essential to continuity of care and close follow-up should follow these patients.

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.

Ovulation induction drug and ovarian cancer: an updated systematic review and meta-analysis

OBJECTIVE

To explore the association between ovulation induction drugs and ovarian cancer.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women without ovarian cancer who ever or never underwent ovarian induction.

INTERVENTION(S)

An extensive electronic search of the following databases was performed: PubMed, EMBASE, MEDLINE, Google Scholar, Cochrane Library and CNKI, from inception until January 2022. A total of 34 studies fulfilled our inclusion criteria and were included in the final meta-analysis. The odds ratio (OR) and random-effects model were used to estimate the pooled effects. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Funnel plots and Egger tests were used to assess publication bias.

MAIN OUTCOMES

New diagnosed borderline ovarian tumor (BOT) and invasive ovarian cancer (IOC) between ovulation induction (OI) group and control (CT) group considering fertility outcome, OI cycles and specific OI drugs.

RESULTS

Primarily, there was no significant difference in the incidence of IOC and BOT between the OI and CT groups. Secondly, OI treatment did not increase the risk of IOC and BOT in the multiparous women, nor did it increase the risk of IOC in the nulliparous women. However, the risk of BOT appeared to be higher in nulliparous women treated with OI treatment. Thirdly, among women exposed to OI, the risk of IOC and BOT was higher in nulliparous women than in multiparous women. Fourthly, the risk of IOC did not increase with increasing OI cycles. Lastly, exposure to specific OI drugs also did not contribute to the risk of IOC and BOT.

CONCLUSION

Overall, OI treatment did not increase the risk of IOC and BOT in most women, regardless of OI drug type and OI cycle. However, nulliparous women treated with OI showed a higher risk of ovarian cancer, necessitating their rigorous monitoring and ongoing follow-up.

Real-world prescription patterns for reproductive assistance patients in China: A trend analysis from 2016 to 2020

Background: Pharmacotherapy is one of the primary treatments for patients with Assisted reproductive technology (ART). Despite the publication of various research on ART treatment, there is no clear conclusion regarding the choice of drug treatment in China. Our research intends to examine the trend of widely prescribed medications for ART patients in China. For instance, the study examines the logic of drug indications, usage, and dose in patient prescriptions.

Methods: We did a cross-sectional study of the data from the hospital prescription analysis cooperation project supervised by the China Medical Association. The information is extracted from the prescriptions of reproductive assistance outpatients from January 2016 to December 2020. We used the U.S. Food and Drug Administration (FDA) classification to quantify the frequency of drug use and the categories of drugs. We manually extract the information of patients who require ART treatment, divide the patients into various age groups and geographies, followed by study the indications, utilization, and rationale of the most important therapeutic medications.

Results: Among the 225225 patients included in this study, Guangzhou (47.83%), Shanghai (19.84%), and Zhengzhou (9.36%) were the top three cities. In the past 5 years, the average age was 32.99, and 60.38% of women were between the age of 25 and 34. The main therapeutic medicines taken by each patient, primarily hormone therapies, were tallied. Eleven types of primary therapeutic medicines were employed. Different progesterone preparations (47472, 21.08%), chorionic gonadotrophin gondotrophin for injection (38932, 17.29%), dydrogesterone tables (33591, 14.91%), and triptorelin for injection (26959, 11.97%) rounded out the top five. According to the data on outpatient medications in major cities in China, the variety and proportion of injections are the highest, including the most frequent types of ovulation induction and urotropia, as well as triptorelin and progesterone. Even though the total dosage of urotropin was the highest in 5 years, it showed a declining trend. The dosages of progesterone and didroxyprogesterone increased, with progesterone showing the most rapid increase. The top five most expensive prescription medications are triptorelin, urotropin, progesterone, didroxyprogesterone, and leuprorelin, in that order. Goserelin, leuprorelin, triptorelin, growth hormone, and didroxyprogesterone are among the top five most expensive medications per capita.

Conclusion: The average age of patients has not increased considerably over the past 5 years. However, the opportunity cost of childbirth for women has increased, which has significantly enhanced their willingness for childbearing intentions. The medication selection is reasonable overall. In this study, the recommended dosages of first-line medicines (urotropin and chorionic gonadotropin) are likewise high. In contrast, the dosage of oral first-line treatment for ovarian stimulation in unexplained infertility is modest, and the dosage of progesterone is steadily increasing. In addition, the price of certain medicines is high, which will increase the patients’ financial burden. Future research will focus on enhancing the degree of rational drug use among outpatients and realizing the economical, safe, and effective use of pharmaceuticals to lessen the economic burden of patients.

The Prevalence of Fallopian Tube Occlusion in Women with Polycystic Ovary Syndrome Seems Similar to Non-Subfertile Women: A Retrospective Cohort Study

There are limited data on how non-infectious risk factors influence tubal patency in women with subfertility. With hormonal shifts influencing tubal secretions, it has been argued that subfertile women with polycystic ovary syndrome (PCOS) have lower tubal patency. In a retrospective study, 216 women, who underwent diagnostic evaluation for PCOS and infertility, were included. Fallopian tube patency was tested using HSG, HyCoSy, and laparoscopic chromopertubation in 171 (79.2%), 28 (13.0%), and 17 (7.9%), respectively. Bilateral patency was found in 193 women (89.4%), unilateral patency in 13 (6.0%) and bilateral occlusion in 10 (4.6%) patients. Women with PCOS phenotypes C (odds ratio, OR 0.179, 95% CI: 0.039–0.828) and D (OR 0.256, 95% CI: 0.069–0.947) demonstrated lower risks for Fallopian tube occlusion. In conclusion, our data suggest that about 5% of infertile women with PCOS also have bilateral tubal occlusion, which seems similar to the rate in non-subfertile women. With 11% of participants having unilateral or bilateral tubal occlusion, this should reassure women with PCOS that their hormonal challenges do not seem to increase their risk for tubal factor subfertility.

Abnormal Endometrial Receptivity and Oxidative Stress in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women of childbearing age. Individual heterogeneity is evident, and the prevalence rate ranges between 6 and 15% globally. The prevalence rate of PCOS in Chinese women of childbearing age is 5.6%. The main manifestations are infertility, sparse menstruation, irregular vaginal bleeding, long-term endometrial hyperplasia, and endometrial cancer. PCOS is often associated with hyperandrogenemia, insulin resistance, hyperinsulinemia, obesity, metabolic syndrome, and intestinal flora disorder. Although there have been many studies in the past, the underlying pathophysiological mechanism of the disease is still unclear. Studies have shown that PCOS diseases and related complications are closely related to local oxidative stress imbalance in the endometrium, leading to poor endometrial receptivity and effects on pregnancy. Previous reviews have mainly focused on the abnormal mechanism of ovarian oxidative stress in women with PCOS, while reviews on endometrial receptivity and oxidative stress are relatively insufficient. This study reviews the abnormal cellular and molecular mechanisms of oxidative stress due to comorbidities in women with PCOS, leading to a downregulation of endometrial receptivity.

Successful pregnancy with restorative reproductive medicine after 16 years of infertility, three recurrent miscarriages, and eight unsuccessful embryo transfers with in vitro fertilization/intracytoplasmic sperm injection: a case report

BACKGROUND

Restorative reproductive medicine represents a comprehensive approach to subfertility (infertility and miscarriage) with investigations, diagnoses, and treatments combined with fertility charting to restore optimal reproductive function. Restorative reproductive medicine assumes that multiple factors need to be identified and treated (cycle optimization) for up to 12 cycles to achieve a successful pregnancy. Conception can occur during normal intercourse without intrauterine insemination or in vitro fertilization.

CASE PRESENTATION

A 35-year-old Croatian female presented for fertility treatment in May 2019 with a previous diagnosis of polycystic ovaries, infertility of 16 years duration, and 8 unsuccessful embryo transfers with in vitro fertilization and intracytoplasmic sperm injection. She was gravida 3 para 0, with 2 miscarriages after spontaneous conception at 5-6 weeks gestation in 2002 and 2004, followed by a miscarriage after in vitro fertilization at 12 weeks gestation in 2011. We initially found poor follicle function and suboptimal progesterone levels. Restorative reproductive medicine treatment resulted in conception after two cycles of treatment. This pregnancy ended in miscarriage at 7 weeks 4 days. Additional investigations found a balanced Robertsonian translocation (13, 14) and a uterine septum. We achieved repeat fertilization with restorative reproductive medicine after three cycles of treatment following resection of the uterine septum and ovulation induction with letrozole and human chorionic gonadotrophin. She had a full-term healthy pregnancy and live birth in 2021.

CONCLUSION

We propose that a full evaluation of underlying factors, and up to 12 cycles of cycle optimization, should be offered to subfertile patients before considering in vitro fertilization treatment.

Parameters for Calcium Metabolism in Women with Polycystic Ovary Syndrome Who Undergo Stimulation with Letrozole: A Prospective Cohort Study

For women with polycystic ovarian syndrome (PCOS) and infertility, stimulation with the aromatase-inhibitor letrozole has been recommended as a first-line for ovulation induction. Calcium-associated signaling has also been a component for other ovulation induction and superovulation medications. This study’s aim was to evaluate parameters of calcium metabolism in PCOS women. In a prospective cohort study, 61 anovulatory, infertile PCOS patients who underwent letrozole stimulation were included. Outcome measures were: follicular maturation after letrozole stimulation; parathyroid hormone (PTH); 25-hydroxyvitamin D3 (25OHD3); serum levels of calcium, phosphorus, magnesium, albumin, and total protein. Successful recruitment of a dominant follicle was achieved in 35 patients (57.4%). Women with and without successful follicular development did not differ in serum levels of PTH (38.4 ± 19.7 vs. 39.6 ± 16.2 pg/mL), 25OHD3 (62.5 ± 32.1 vs. 65.4 ± 30.9 nmol/L), calcium (2.36 ± 0.08 vs. 2.37 ± 0.12 mmol/L), or protein (70.2 ± 13.3 vs. 74.0 ± 3.7 g/L), respectively (p > 0.05). However, women who were not responsive to letrozole for ovulation induction demonstrated higher anti-Müllerian hormone (AMH) levels (9.7 ± 4.7 vs. 5.0 ± 3.2 ng/mL, p = 0.005). In conclusion, the success of letrozole stimulation in women with PCOS is independent from calcium metabolism parameters. However, AMH levels seem predictive of medication resistance.

A Randomized Cohort Study: Is It Worth the Time to Receive Antiandrogenic Pretreatment Before Ovulation Induction for Women With Polycystic Ovary Syndrome?

Objective

To assess the effect of antiandrogenic pretreatment using combined oral contraceptives (COCs) before ovulation induction in infertile patients with polycystic ovary syndrome (PCOS) with hyperandrogenism.

Design

Prospective, randomized open-labeled cohort study.

Setting

Multicenter.

Patients

PCOS patients with hyperandrogenism and requiring infertility treatments.

Interventions

Randomization to direct ovulation induction of letrozole (letrozole group) or ethinylestradiol/cyproterone acetate (EE/CPA) for 3 months and subsequent letrozole-induced ovulation (EE/CPA+ letrozole group). The maximum number of ovulation induction cycle was three to four.

Main Outcome Measures

Ovulation rate, conception rate, ongoing pregnancy rate, and live birth rate were the main outcomes of the study.

Results

There were no significant differences in the cumulative ovulation, conception, ongoing pregnancy, and live birth rates between the letrozole and EE/CPA+ letrozole groups (cumulative ovulation: 206/254 [81.10%] vs. 169/205 [82.44%], risk ratio [RR]= 1.09 [0.68,1.76], P=0.713; conception: 44/90 [48.89%] vs. 42/76 [55.26%], RR= 1.29 [0.70,2.38], P=0.413; ongoing pregnancy: 33/90 [36.67%] vs. 33/76 [43.42%], RR=1.33 [0.71,2.47], P=0.376; and live birth: 32/90 [35.56%] vs. 31/76 [40.79%], RR=1.25 [0.67, 2.34], P=0.489).

Conclusions

The results of this study showed that COC pretreatment was not superior to direct letrozole-induced ovulation therapy in improving ovulation and pregnancy results in women with PCOS. There is no benefit to perform antiandrogenic therapy before ovulation induction in patients with PCOS in clinical practice.

Clinical Trial Registration

www.clinicaltrials.gov, identifier ChiCTR1900022839.

Retrospective analysis: The application of human menopausal gonadotropin combined with letrozole for IUI in patients undergoing artificial insemination by husband due to unexplained or mild male factors

OBJECTIVE

To compare the effects of human menopausal gonadotropin (HMG) combined with letrozole (LE) to HMG only for ovarian stimulation on pregnancy outcome of infertile patients undergoing artificial insemination by husband (AIH) due to unexplained or mild male factors.

MATERIALS AND METHODS

Infertile patients with unexplained or mild male factors treated from July 2015 to December 2021 were selected as subjects. The patients were divided into two groups according to the ovarian stimulation schemes they received, namely HMG combined with LE or HMG only. We analyzed the laboratory examination results before drug treatment (baseline) and during ovarian stimulation and compared the pregnancy outcomes of the two groups using univariable analysis and multivariable logistic regression analysis.

RESULTS

In total, 526 cycles of 372 couples were included. The univariate analysis showed that the clinical pregnancy rate of the HMG combined with LE group was 24.8%, significantly higher than that of the HMG group (14.8%, P = 0.007). The live birth rate (19.9%) of the HMG combined with LE group were also significantly higher than those of the HMG group (11.2%, respectively). In multivariate logistic analysis, the age of males was negatively associated with the clinical pregnancy rate (OR 0.874, 95% CI 0.793~0.963, P=0.006) and live birth (OR0.875, 95% CI 0.783~0.977, P=0.018). Moreover, ovarian stimulation with HMG+LE was the only beneficial factor significantly associated with clinical pregnancy (OR 1.929, 95% CI 1.068~3.485, P=0.029) and live birth (OR 2.255, 95% CI 1.188~4.282, P=0.013).

CONCLUSION

Ovarian stimulation using HMG combined with LE can increase the clinical outcomes (live birth and clinical pregnancy) among infertile patients undergoing AIH due to explained or mild male factors.

Myo-Inositol as a Key Supporter of Fertility and Physiological Gestation

Pregnancy is a complex process, featuring several necessary changes in women’s physiology. Most women undergo healthy pregnancies; even so, several women experience reduced fertility or pathologies related to the pregnancy. In the last years, researchers investigated several molecules as promoters of fertility. Among all, myo-inositol (myo-ins) represents a safe compound that proved useful in issues related to fertility and pregnancy. In fact, myo-ins participates in several signaling processes, including the pathways of insulin and gonadotropins, and, therefore, it is likely to positively affect fertility. In particular, several clinical trials demonstrate that its administration can have therapeutic effects in infertile women, and that it can also be useful as a preventive treatment during pregnancy. Particularly, myo-ins could prevent the onset of neural tube defects and the occurrence of gestational diabetes mellitus, promoting a trouble-free gestation. Due to the safety and efficiency of myo-ins, such a treatment may also substitute several pharmaceuticals, which are contraindicated in pregnancy.

Therapeutic Potentials of Low-Dose Tacrolimus for Aberrant Endometrial Features in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a major anovulatory infertility affecting a great proportion of women of childbearing age and is associated with obesity, insulin resistance and chronic inflammation. Poor endometrial receptivity and recurrent implantation failure are major hurdles to the establishment of pregnancy in women with PCOS. The accumulating body of evidence obtained from experimental and clinical studies suggests a link between inherent adaptive and innate immune irregularities and aberrant endometrial features in PCOS. The use of conventional therapeutic interventions such as lifestyle modification, metformin and ovarian stimulation has achieved limited clinical success in restoring ovulation and endometrial receptivity in women with PCOS. Unlike other immunosuppressive drugs prescribed in the clinical management of autoimmune and inflammatory disorders that may have deleterious effects on fertility and fetal development, preclinical studies in mice and in women without PCOS but with repeated implantation failure revealed potential therapeutic benefits for the use of low-dose tacrolimus in treating female infertility. Improved systemic and ovarian immune functions, endometrial progesterone receptor and coreceptor expressions and uterine vascular adaptation to pregnancy were among features of enhanced progesterone-receptor sensitivity in the low-dose tacrolimus-treated mouse model of the disease. In this review, we have compiled available experimental and clinical data in literature on endometrial progesterone resistance and current therapeutic options, as well as mechanisms of actions and reported outcomes relevant to the potential therapeutic benefits for the use of low-dose tacrolimus in treating PCOS-associated female infertility.