Letrozole for Female Infertility

Activity of isoflavone in managing polycystic ovary syndrome symptoms (Review)

Polycystic ovary syndrome (PCOS), a hormonal and metabolic disorder manifested in women of reproductive age, is still being treated using drugs with side effects. As an alternative to these drugs, isoflavone, also identified as phytoestrogen, has anti-PCOS activity. Isoflavone can help relieve PCOS symptoms by lowering the level of testosterone, which causes hyperandrogenism, thereby normalizing the menstrual cycle and restoring normal ovarian morphology. Furthermore, isoflavone influences the improvement of the metabolic profile, which changes because of PCOS, as well as the reduction of inflammatory markers and oxidative stress. However, both significant and non-significant results have been generated on the activity of isoflavones in PCOS. The present review aims to discuss the existing literature on the effect of isoflavone on PCOS symptoms based on in vivo and clinical trial studies.

Letrozole cotreatment progestin-primed ovarian stimulation in women undergoing controlled ovarian stimulation for in vitro fertilization

AIM

To investigate the impact of letrozole cotreatment progestin-primed ovarian stimulation (PPOS) (Le PPOS) in controlled ovarian stimulation (COS) and the pregnancy outcomes in frozen-thawed embryo transfer cycles.

METHODS

This retrospective cohort study included women who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). A total of 2575 cycles were included (1675 in the Le PPOS group and 900 in the PPOS group). The primary outcome was the clinical pregnancy rates. The secondary outcome was the live birth rates.

RESULTS

In this study, propensity score matching (PSM) was performed to create a perfect match of 379 patients in each group. After matching, the numbers of oocytes retrieved, mature oocytes, fertilization, and clinical pregnancy rates were more favorable in the Le PPOS group than in the PPOS group (all p < 0.05). The multivariable analysis showed that the clinical pregnancy rate was higher in the Le PPOS than in the PPOS group (odds ratio = 1.46, 95% confidence interval: 1.05-2.04, p = 0.024) after adjusting for potentially confounding factors (age, anti-Müllerian hormone levels, antral follicular count, the type of embryo transferred, number of transferred embryos, body mass index, and follicular stimulating hormone and estradiol levels on starting day).

CONCLUSIONS

This retrospective study with a limited sample size suggests that the Le PPOS protocol might be an alternative to the PPOS protocol in women undergoing COS and could lead to better pregnancy outcomes. The results should be confirmed using a formal randomized controlled trial.

Effect of Consultation Number on the Assessment and Treatment of Polycystic Ovary Syndrome

Background

The basic medical education stage is not enough to support physicians to fully diagnose and evaluate polycystic ovary syndrome (PCOS). The study aims to discover the difference in treatment choice between participants with different annual consultation number of PCOS, to promote lifelong learning, and drive balanced development within healthcare.

Methods

This is a multicenter cross-sectional survey. Participants' basic information, knowledge of PCOS and treatment options were collected online. According to the annual consultation number of patients with PCOS, physicians were divided into three groups: 0-50 people/yr, 50-200 people/yr, and >200 people/yr, and the results were derived from χ2 test, Fisher exact test, and multivariate logistic regression analysis.

Results

The study analyzed 1689 questionnaires, and 1206 physicians (71.4%) received less than 50 women per year, 388 physicians (30.0%) with an annual number of 50-200 women, and 95 physicians (5.6%) with patient turnover for more than 200 people. Reproductive endocrinologists generally have higher access to the clinic. As the number of visits increases, more and more physicians would perceive patients as more likely to have abnormal blood glucose and heavy weight. Physicians with large numbers of consultations are more likely to use Asian or Chinese standards to assess obesity. The multivariate analysis involved variables such as age, hospital level, specialty, and patient turnover annually, and more young doctors actively assessed lipid profile (odds ratio (OR) 1.56, 95% confidence interval (CI) (1.16, 2.16)), and primary hospitals (OR 0.65 CI (0.44, 0.89)) chose OGTT for blood glucose assessment less than tertiary hospitals. Physicians in secondary hospitals are more aggressive in evaluating androgens.

Conclusion

Our survey found differences in endocrine assessment, metabolic screening, and treatment in PCOS women in terms of the number of obstetrician-gynecologists who received different patient consultation numbers. The importance of continuing education for physicians is emphasized, to promote lifelong learning.

Successful live birth of thin endometrium: A case report

RATIONALE

The success of pregnancy depends on various factors, with the endometrial receptivity being a crucial component. Endometrial thickness (EMT) serves as a direct indicator for assessing endometrial receptivity. Previous studies have suggested that a thin endometrium is associated with lower pregnancy rates, especially in patients with an EMT of less than 4 mm. Even in assisted reproductive technology cycles with high success rates, clinical pregnancy cases in patients with such thin endometrium are reported to be very few, let alone in natural conception cycles. Therefore, a thin endometrium poses significant challenges for infertility patients. In this study, patients with an extremely thin endometrium were able to achieve clinical pregnancy and successful live births through natural conception, highlighting the possibility of success even in challenging cases.

PATIENT CONCERNS

The patient presented with polycystic ovary syndrome and ovulation disorders. She underwent a natural cycle of letrozole-induced ovulation. On the day of the human chorionic gonadotropin trigger, she had an EMT of 3.8 mm.

DIAGNOSES

Polycystic ovary syndrome, ovulation disorders, thin endometrium.

INTERVENTIONS

The patient received medications including Progynova, Aspirin, and Dydrogesterone.

OUTCOMES

The patient achieved spontaneous conception and subsequently had a live birth.

LESSONS

This case report underscores the significance of managing a thin endometrium during letrozole-induced ovulation. While EMT is traditionally pivotal for predicting embryo implantation success, our findings indicate that endometrial receptivity extends beyond thickness alone. Factors such as endometrial morphology, type, and blood supply play crucial roles. Successful pregnancies with a 3.8 mm EMT are rare, making this case a beacon of hope for such patients. It highlights that, with appropriate interventions, successful pregnancies remain attainable. For those with a thin endometrium, emphasis should extend beyond thickness, addressing ways to enhance both endometrial blood supply and morphology for improved pregnancy rates.

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.

A comparative study of green solid contact ion selective electrodes for the potentiometric determination of Letrozole in dosage form and human plasma

Analysis of drugs clinically and their identification in biological samples are of utmost importance in the process of therapeutic drug monitoring, also in pharmacokinetic investigations and tracking of illicit medications. These investigations are carried out using a variety of analytical methods, including potentiometric electrodes. Potentiometric electrodes are a wonderful solution for researchers because they outperform other methods in terms of sustainability, greenness, and cost effectiveness. In the current study, ion-selective potentiometric sensors were assembled for the aim of quantification of the anticancer drug Letrozole (LTZ). The first step was fabrication of a conventional sensor based on the formation of stable host-guest inclusion complex between the cationic drug and 4-tert-butylcalix-8-arene (TBCAX-8). Two additional sensors were prepared through membrane modification with graphene nanocomposite (GNC) and polyaniline (PANI) nanoparticles. Linear responses of 1.00 × 10-5-1.00 × 10-2, 1.00 × 10-6-1.00 × 10-2 and 1.00 × 10-8-1.00 × 10-3 with sub-Nernstian slopes of 19.90, 20.10 and 20.30 mV/decade were obtained for TBCAX-8, GNC, and PANI sensors; respectively. The developed sensors were successful in determining the drug LTZ in bulk powder and dosage form. PANI modified sensor was used to determine LTZ in human plasma with recoveries ranging from 88.00 to 96.30%. IUPAC recommendations were followed during the evaluation of the electrical performance of the developed sensors. Experimental conditions as temperature and pH were studied and optimized. Analytical Eco-scale and Analytical GREEness metric were adopted as the method greenness assessment tools.

Successful delivery after in vitro fertilization-embryo transfer in a woman with metachronous primary cancer of ovary and endometrium: a case report

BACKGROUND

The appearance of malignancies at various times in the same individual, excluding metastases of the initial primary cancer, is termed multiple primary cancers. Double primary gynecological cancers cause inevitable damage to female reproductive function, and the preservation of fertility in such patients remains a challenging issue as relatively few cases have been reported. This case report provides management options for dual primary ovarian and endometrial cancers, including the choice of ovulation induction protocols, considerations during pregnancy and parturition, with the aim of providing assistance to clinicians.

CASE PRESENTATION

We report a case of a 39-year-old woman with primary infertility and a medical history of right-sided ovarian mucinous borderline tumor with intraepithelial carcinoma, left-sided ovarian mucinous cystadenoma and endometrial cancer, who successfully conceived with in vitro fertilization-embryo transfer (IVF-ET) after three different ovulation induction protocols. During her pregnancy, she was complicated by central placenta praevia with placental implantation and eventually delivered a healthy female infant by caesarean section at 33 gestational weeks.

CONCLUSIONS

For patients with double primary gynecological cancers who have an intense desire for fertility, the most appropriate oncological treatment should be applied according to the patient's individual situation, and fertility preservation should be performed promptly. Ovulation induction protocol should be individualized and deliberate, with the aim of ensuring that the patient's hormone levels do not precipitate a recurrence of the primary disease during induction of ovulation and maximizing fertility outcomes. In addition, the risk of postpartum hemorrhage due to placental factors cannot be neglected in such patients.

Computational screening of FDA-approved drugs to identify potential aromatase receptor inhibitors for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common cause of infertility without ovulation. Aromatase inhibitors were first proposed as new ovulation-inducing drugs in anovulatory women with an inadequate response to clomiphene. Letrozole is an aromatase inhibitor used as an ovulation inducer in infertile women due to PCOS. However, there is no definitive treatment for women with PCOS and the treatments are mostly symptomatic. In this study, we intend to introduce alternative drugs to letrozole using the library of FDA-approved drugs and evaluate the interaction of these drugs with the aromatase receptor. For this aim, molecular docking was performed to identify interactions of FDA-approved drugs with essential residues in the active site of the aromatase receptor. 1614 FDA-approved drugs were docked with aromatase receptor using AutoDock Vina. Molecular dynamics (MD) simulation study was also performed for 100 ns to verify the stability of the drug-receptor complexes. MMPBSA analysis evaluate the binding energy of selected complexes. Finally, acetaminophen, alendronate, ascorbic acid, aspirin, glutamine, hydralazine, mesalazine and pseudoephedrine drugs showed the best results in interaction with aromatase receptor based on computational studies. These drugs can be introduced as an alternative to letrozole for treating PCOS.Communicated by Ramaswamy H. Sarma.

L-Carnitine alleviates hepatic and renal mitochondrial-dependent apoptotic progression induced by letrozole in female rats through modulation of Nrf-2, Cyt c and CASP-3 signaling

Letrozole (LTZ) is a non-steroidal aromatase inhibitor that is commonly used in breast cancer therapy. It has several side effects that might lead to the drug's cessation and data of LTZ's potential adverse effects on the hepatorenal microenvironment was conflicting. In addition, searching for therapeutic interventions that could modulate its adverse effects will be very beneficial. So, this study aims to determine the impact of LTZ on the hepatorenal microenvironment in cyclic female rats with a proposed regulatory role of L-Carnitine (LC) supplementation giving molecular insights into its possible mechanism of action. LTZ (1 mg/kg using 0.5% carboxy methyl cellulose as a vehicle for 21 consecutive days orally) to assess its impact on hepatorenal microenvironment. After treatment with LC (100 mg/kg orally) for 14 days, hepatorenal redox state (lipid peroxides (MDA), reduced glutathione (GSH) and catalase enzyme (CAT)), as well as relative gene expression of nuclear factor erythroid 2-related factor 2 (Nrf-2), cytochrome-c (Cyt c) and caspase-3 (CASP-3) were evaluated. Histopathological examination and immunohistochemical staining of CASP-3 in both liver and kidney were done. LTZ altered hepatic and renal functions. Relative gene expression of hepatorenal Nrf-2, Cyt c and CASP-3 as well as redox state revealed significant deterioration. Also, the liver and kidney tissues showed several micromorphological changes and intense reaction to CASP-3 upon immunohistochemical staining. It can be concluded that LC alleviates LTZ induced hepatorenal oxidative stress (OS) and mitochondrial-dependent apoptotic progression through modulation of Nrf-2, Cyt c, and CASP-3 signaling in female rats.

Letrozole cotreatment improves the follicular output rate in high-body-mass-index women with polycystic ovary syndrome undergoing IVF treatment

BACKGROUND

Women who have polycystic ovary syndrome (PCOS) with high body mass index (BMI) typically have an attenuated ovarian response and decreased follicular size, which are linked to unfavourable clinical outcomes following in vitro fertilization (IVF) therapy. The follicular output rate (FORT), a qualitative indicator of follicular response, seems to be positively linked to the clinical outcomes of IVF. Progestin-primed ovarian stimulation (PPOS) has become an alternative to gonadotropin-releasing hormone (GnRH) analogues to inhibit the premature luteinizing hormone (LH) surge. As letrozole (LE) shows promise in enhancing ovarian response, we compared PPOS with and without LE for PCOS in high BMI women with a focus on the FORT and associated clinical and pregnancy outcomes.

METHODS

For the recruited 1508 women, ten variables including AFC; age; basal sex hormone level; BMI; infertility type; period of infertility and number of previous IVF attempts were chosen in the propensity score matching (PSM) model to match 1374 women who taken the MPA+ hMG protocol with 134 women who received the MPA+ hMG+ LE treatment at a 1:1 ratio. FORT was selected as the primary outcome measure. The number of oocytes retrieved, viable embryos, hMG dosage, duration, oocyte maturity rate, fertilization rate, and implantation rate were established as secondary outcomes.

RESULTS

FORT was substantially elevated in the MPA+hMG+LE group compared with the MPA+hMG group (61% [35%, 86%] vs. 40% [25%, 60%], P <.001). Interestingly, the LE cotreatment group had a considerably lower mature oocyte rate despite having a similar number of mature oocytes and embryos recovered. The average hMG dosages and durations in the study group were similar to those in the control group. The implantation rate in the study group was numerically higher but without statistic significant than that in the control groups (43.15% (107/248) vs. 38.59% (115/298), OR 1.008, 95% CI 0.901-1.127; P >.05).

CONCLUSION

The effect of LE combined with PPOS on FORT is better than the effect of the standard PPOS treatment in women with PCOS and a high BMI, but there is no substantially beneficial impact on pregnancy outcomes or the cycle features of COS, including consumption of hMG.

Hypothalamic-Pituitary-Gonadal Axis Disorders Impacting Fertility in Both Sexes and the Potential of Kisspeptin-Based Therapies to Treat Them

Impaired function of the hypothalamic-pituitary-gonadal (HPG) axis can lead to a vast array of reproductive disorders some of which are inherited or acquired, but many are of unknown etiology. Among the clinical consequences of HPG impairment, infertility is quite common. According to the latest report from the World Health Organization, the global prevalence of infertility during a person's lifetime is a staggering 17.5% which translate into 1 out of every 6 people experiencing it. In both sexes, infertility is associated with adverse health events, and if unresolved, infertility can cause substantial psychological stress, social stigmatization, and economic strain. Even though significant advances have been made in the management and treatment of infertility, low or variable efficacy of treatments and medication adverse effects still pose a significant problem. However, the discovery that in humans inactivating mutations in the gene encoding the kisspeptin receptor (Kiss1R) results in pubertal failure and infertility has expanded our understanding of the mechanisms underlying the neuroendocrine control of reproduction, opening up potential new therapies for the treatment of infertility disorders. In this chapter we provide an overview of common infertility disorders affecting men and women, their recommended treatments, and the potential of kisspeptin-based pharmacotherapies to treat them.

Letrozole as premedication of high intensity focused ultrasound treatment of uterine fibroids: A retrospective observation study

Background

No reports on Letrozole as a pretreatment before ablation of uterine fibroid with high intensity focused ultrasound (HIFU), so a retrospective observation study was performed to evaluate the response of different pre-HIFU medication.

Methods

We collected patients with single uterine fibroid receiving HIFU ablation from January 2018 to April 2021. All enrolled patients were classified into three group: group A (no pre-HIFU medication use), group B (Pre-HIFU letrozole use), group C (pre-HIFU gonadotrophin releasing hormone analog, GnRHa). Further associated clinical data and treatment response after HIFU treatment were reviewed and evaluated.

Results

A total of 39 patients including 21, 7, and 11 in group A, B, and C were collected respectively. After pre-HIFU medication, no difference of fibroid volume was found (A: 251.4, B: 360.6, C: 409.4 cm³, p = 0.250), and GnRHa group had significantly larger volume reduction than Letrozole users (38.6% vs. 16.4%, p = 0.007). The incidence of hypoestrogenic symptoms was higher in GnRHa group than in letrozole users (27.3% vs. 0, p = 0.170). GnRHa group had more sonication time (p = 0.001), treatment duration (p = 0.002), and ablated energy (p = 0.001) than group A and B. The treatment efficiency was higher in letrozole group than that in other 2 groups (4.52 vs. 2.39 vs. 2.34 cm³/min, p = 0.050). For patients with fibroid over 10 cm in diameter, letrozole group had even better energy efficiency (p = 0.067), treatment speed (p = 0.007), treatment efficiency (p = 0.001), NPV per energy (p = 0.005), and NPV per sonication (p = 0.004) than other 2 groups.

Conclusion

Letrozole as a pretreatment medication before HIFU treatment might increase the energy efficiency and treatment efficiency of its ablation of uterine leiomyoma, especially for fibroid over 10 cm. Future study of larger patient number is needed to confirm our results.

The impact of letrozole on oocyte quality in assisted reproductive technology (ART); a randomized double-blind clinical trial

OBJECTIVE

To examine the effect of letrozole on oocyte quality and pregnancy outcome in assisted reproductive technology (ART).

METHODS

This double blind placebo controlled clinical trial was conducted in Vali-Asr Infertility Center. Infertile women candidate for IVF that underwent antagonist protocol were selected. Eligible women randomly allocated into treatment (letrozole/Let group) and control (placebo) group. Participants received letrozole 5 mg/day or placebo at the time of gonadotropin start until trigger day in the same manner. Number of oocyte retrieved, metaphase II oocyte number, high grade oocyte number (G1), high quality embryo, Chemical and clinical pregnancy rate and OHSS (ovarian hyperstimulation syndrome) rate was recorded. 216 infertile women (104 in letrozole and 112 in the control group) were evaluated.

RESULTS

In the Let group estradiol level was significantly lower (p_value < .001) and testosterone significantly higher than in the control group (p_value = .02). The number of retrieved oocytes, MII oocytes, G1 oocytes, and 2PN was significantly lower in the Let group (p < .05). No significant difference was found in the day of stimulation, total gonadotropin dose, OHSS rate, and clinical pregnancy rate between the two groups (p > 0.05).

CONCLUSIONS

According to the results, letrozole may reduce oocyte quality and cause poor IVF outcomes as well.

Resistant ovary syndrome: Pathogenesis and management strategies

Resistant ovary syndrome (ROS) is a rare and difficult gynecological endocrine disorder that poses a serious risk to women’s reproductive health. The clinical features are normal sex characteristics, regular female karyotype, and usual ovarian reserve, but elevated endogenous gonadotropin levels and low estrogen levels with primary or secondary amenorrhea. Although there have been many case reports of the disease over the past 50 years, the pathogenesis of the disease is still poorly understood, and there are still no effective clinical management strategies. In this review, we have collected all the current reports on ROS and summarized the pathogenesis and treatment strategies for this disease, intending to provide some clinical references for the management and treatment of this group of patients and provide the foothold for future studies.

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.

Letrozole cotreatment with progestin-primed ovarian stimulation in women with polycystic ovary syndrome undergoing IVF treatment

Background: Progestin is an alternative to gonadotropin-releasing hormone (GnRH) analogues in the follicular phase to suppress the premature luteinizing hormone (LH) surge in women with polycystic ovary syndrome (PCOS). However, progestin-primed ovarian stimulation (PPOS) is always accompanied by increased pituitary suppression and gonadotropin consumption. Previous studies suggested that letrozole appeared to have the potential to reduce the total gonadotropin dose required for ovarian stimulation. A retrospective cohort study was performed to evaluate the efficacy of PPOS with or without letrozole in infertile women with PCOS.

Methods: This retrospective cohort study included 448 women with PCOS who underwent controlled ovarian stimulation (COS) with human menopausal gonadotropin (hMG) and medroxyprogesterone acetate (MPA) (n = 224) or hMG and MPA cotreatment with LE (n = 224) from January 2018 to March 2021 after propensity-score matching. The primary outcome measure was the hMG dose. The secondary outcomes were the durations of ovarian stimulation, the implantation rate, the number of oocytes retrieved and viable embryos, oocyte maturity and fertilization rates, the percentage of women with profound pituitary suppression (luteinizing hormone [LH] <1.0 IU/L on the trigger day).

Results: The hMG doses (1949.89 ± 725.03 IU vs 2017.41 ± 653.32 IU,p > 0.05) and durations of ovarian stimulation (9.03 ± 1.79 days vs 9.21 ± 2.18 days,p > 0.05) were similar between the two groups. The implantation rate was significantly higher in the study group (MPA + hMG + LE) than in the control group (MPA + hMG) (42.22 vs 34.69%, p < 0.05). The numbers of oocytes and embryos retrieved were similar between the two groups. Interestingly, letrozole cotreatment was associated with decreased oocyte maturity and fertilization rates in comparison with standard PPOS protocols even though mature and fertilized oocyte yields were comparable. Compared with those in the control group, the LH values on the trigger day were significantly higher in the study group, together with significantly reduced pituitary suppression.

Conclusion: Letrozole combined with PPOS cannot reduce hMG consumption in PCOS patients undergoing IVF treatment and shows no beneficial effect on cycle characteristics of COS. However, letrozole supplementation manifests as a superior implantation rate to that of the standard PPOS protocol in women with PCOS.

Effects of letrozole co-treatment on outcomes of gonadotropin-releasing hormone antagonist cycles in POSEIDON groups 3 and 4 expected poor responders

PURPOSE

To evaluate the effects of adjuvant letrozole administration on outcomes of gonadotropin-releasing hormone (GnRH) antagonist cycles with intra-cytoplasmic sperm injection in POSEIDON groups 3 and 4 expected poor responder women.

METHODS

This study was conducted by retrospective analysis of patients with expected poor ovarian response (POSEIDON groups 3 and 4) that underwent GnRH antagonist cycles with intra-cytoplasmic sperm injection between 2010 and 2020. A total of 488 patients with letrozole co-administration and 2564 patients without any adjuvant treatment that underwent GnRH antagonist cycles within the selected period of time were included in the study.

RESULTS

Implantation rates, clinical pregnancy rates and live birth delivery rates were significantly higher in letrozole administered patients in comparison to controls among POSEIDON group 3 women (0.39 ± 0.46 vs 0.27 ± 0.40, p = 0.01; 46.1% vs 33%, p = 0.014; 42.7% vs 31.5%, p = 0.034, respectively). Mean total doses of gonadotropins required per cycle were significantly lower in letrozole administered patients among both POSEIDON groups 3 and 4 women (2864.65 ± 878.47 IU vs 3757.27 ± 1088.89 IU, p < 0.001; 3286.06 ± 770.16 IU vs 3666.48 ± 959.66 IU, p < 0.001, respectively).

CONCLUSION

Adjuvant letrozole co-administration in intra-cytoplasmic sperm injection cycles following GnRH antagonist protocol appears to improve implantation, clinical pregnancy and live birth delivery rates in women with POSEIDON group 3 expected poor ovarian response.

Effects of Fagonia indica on Letrozole-Induced Polycystic Ovarian Syndrome (PCOS) in Young Adult Female Rats

Polycystic ovarian syndrome is a multidisciplinary endocrinopathy of reproductive-aged women that provokes insulin resistance, hyperandrogenism, cardiovascular problems, obesity, and menstrual complications. The present study was designed to investigate the effectiveness of ethanolic extract of Fagonia indica in letrozole-induced PCOS young adult female rats. HPLC was carried out to find the phenolic and flavonoid content of the ethanolic extract of Fagonia indica. Twenty-five female rats were taken and initially divided into two groups: group I (control group) and group II (PCOS group). PCOS was induced by letrozole given orally by gavage. Body weight was recorded weekly and vaginal cytology was analyzed daily. After induction of disease, the PCOS group is further divided into four groups (n = 5): group II (positive control with PCOS), group III (metformin 20 mg/kg treated group), group IV (ethanolic extract of Fagonia indica 500 mg/kg treated group), and group V (metformin plus Fagonia extract). At the end of experimental period, the blood sample of each rat was collected and serum was separated by centrifugation. Afterwards hormonal analysis, lipid profile and liver functioning tests were performed. Ovaries were removed and preserved for histopathological findings while the liver of each rat was stored for the determination of antioxidant potential assessment. Fagonia indica was found to possess quercetin as one of the major flavonoid phytoconstituents. The plant extract exhibited its beneficial effects by restoring hormonal balance, lipid profile, and liver functioning markers. Treatment with F. indica reduced body weight, resolved ovarian cysts, and showed positive effects on follicular growth. Treatment with plant also increased the levels of antioxidant enzymes. This study validates the potential of Fagonia indica for the amelioration of metabolic, as well as, hormonal disturbances that occurred in PCOS.

Efficacy, Safety, and Prognosis of Sequential Therapy with Tamoxifen and Letrozole versus Letrozole Monotherapy for Breast Carcinoma

Objective

To explore the efficacy, safety, and patient prognosis of letrozole (LTZ) alone or in sequence with tamoxifen (TAM) for the treatment of breast carcinoma (BC).

Methods

In this retrospective study, 150 patients with BC who received treatment in the First People's Hospital of Ningyang County between January 2012 and January 2017 were selected. According to different treatment methods, 99 cases receiving sequential therapy with TAM and LTZ were included in the research group, and the remaining 51 patients receiving LTZ monotherapy were selected as the control group. The efficacy, safety, survival rate, recurrence rate, and blood lipid indices (total cholesterol, TC; triglyceride, TG; high-density lipoprotein cholesterol, HDL-C; and low-density lipoprotein cholesterol, LDL-C) of the two groups were observed and compared.

Results

The overall response rate of the research group was statistically higher than that of the control group, and the incidence of adverse reactions was significantly lower. No evident difference was observed in 1-, 3-, or 5-year survival rates between the two groups, while the 3-5-year recurrence rate was obviously lower, and the improvement of blood lipid indices was significantly better in the research group compared with the control group.

Conclusion

LTZ alone or in sequence with TAM is effective and safe for the treatment of BC, which can significantly improve the prognosis and blood lipid indices of BC patients.

Live birth after letrozole as an adjunct to follicle-stimulating hormone versus follicle-stimulating hormone alone for ovarian stimulation in in vitro fertilisation cycles-study protocol for a randomised controlled trial

INTRODUCTION

In vitro fertilisation (IVF) is an effective infertility treatment but the live birth rate remains unsatisfactory. Ovarian stimulation by follicle-stimulating hormone (FSH) is routinely used in IVF and the resulting high serum estradiol levels may impair oocyte/embryo quality and endometrial receptivity. Letrozole, an aromatase inhibitor, can reduce serum estradiol levels following ovarian stimulation. We aim to test the hypothesis that co-treatment with letrozole reduces supraphysiological serum estradiol levels and improves endometrial receptivity, leading to a higher live birth rate of IVF. We are conducting a randomised controlled trial (RCT) to evaluate whether letrozole as an adjunct to FSH in IVF is superior to FSH alone in the live birth rate of fresh embryo transfer.

METHODS/DESIGN

This is an open-label randomised controlled superiority trial being performed in two assisted reproduction centres in China. Infertile women who have antral follicle count (AFC) before ovarian stimulation or on day 5 of ovarian stimulation ≥15 are randomly allocated in a 1:1 ratio to receive either letrozole and FSH or FSH alone in a GnRH antagonist protocol. Recruited women follow the standard operating procedures of the two centres. The primary outcome is the live birth rate of the fresh embryo transfer. Stimulation parameters, maternal side effects and obstetric and perinatal complications are secondary outcomes. The planned sample size is 900, i.e. 450 per group.

DISCUSSION

The present study is the first multicentre randomised study to compare the live birth rate of the fresh embryo transfer following ovarian stimulation by letrozole and FSH versus FSH alone in women with anticipated high ovarian responses.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02912988 . Registered on September 23, 2016. This trial protocol is version 2.0.

Letrozole Supplementation and the Increased Risk of Elevated Progesterone Levels on Trigger Day

Although using letrozole (LE) during in vitro fertilisation and intracytoplasmic sperm injection (IVF/ICSI) has many advantages, it remains unclear whether LE induces an increase in progestogen during the late follicular phase. The objective of this study was to investigate whether progesterone levels increased under antagonist protocols supplemented with LE on the trigger day using a retrospective cohort study. The study included 1,133 women who underwent IVF/ICSI cycles from January 2018 to June 2020. After propensity score matching (PSM) for baseline characteristics, 266 patients with gonadotropin-releasing hormone-antagonist (GnRH-ant) were matched to 266 patients with letrozole + GnRH-ant (LE GnRH-ant) (PSM 1 cohort), and 283 patients with gonadotropin-releasing hormone-agonist (GnRH-a) were matched to 283 patients with LE GnRH-ant (PSM 2 cohort). In the PSM 1 cohort, patients in the LE GnRH-a group presented higher progesterone levels (1.22 ± 0.95 ng/mL vs 0.86 ± 0.60 ng/mL, P < 0.001), with a higher proportion of patients with progesterone level > 1.5 ng/mL (24.81% vs 7.52%, P < 0.001). In PSM 2 cohort, patients in the LE GnRH-a group presented higher progesterone levels on trigger day (1.23 ± 0.91 ng/mL vs 0.98 ± 0.61 ng/mL, P < 0.001), with a higher proportion of patients with progesterone level > 1.5 ng/mL (25.45% vs 12.70%, P < 0.001). In the PSM 1 cohort, progesterone levels on the trigger day increased by 0.05 ng/mL, with an increase in every retrieved oocyte in the LE GnRH-ant group (β 0.05 ng/mL [95% CI 0.04, 0.06], P < 0.001), whereas an increase of 0.02 ng/mL was observed in the GnRH-ant group (β 0.02 ng/mL [95% CI 0.01, 0.03], P < 0.001), with P for interaction being 0.0018. In the PSM 2 cohort, progesterone levels on the trigger day increased by 0.05 ng/mL with an increase in every retrieved oocyte in the LE GnRH-ant group (β 0.05 ng/mL [95% CI 0.04, 0.06], P < 0.001), whereas an increase of 0.02 ng/mL was observed in the GnRH-a group (β 0.02 ng/mL [95% CI 0.01, 0.03], P < 0.001), with P for interaction being 0.0002. LE supplementation on the antagonist protocols may increase progesterone levels in the late follicular stage.

Co-Administration of Clomiphene Citrate and Letrozole in Mild Ovarian Stimulation Versus Conventional Controlled Ovarian Stimulation Among POSEIDON Group 4 Patients

This retrospective study assessed the effect of the co-administration of clomiphene citrate (CC) and letrozole in mild ovarian stimulation, compared to conventional regimens, among Patient-Oriented Strategies Encompassing Individualized Oocyte Number (POSEIDON) Group 4 patients. There were 114 POSEIDON Group 4 patients undergoing in vitro fertilization treatments with 216 stimulation cycles recruited from a Taiwan's reproductive center during 2016-2020. Main outcomes were the numbers, quality of retrieved oocytes and embryo development. Pregnancy outcomes were assessed after embryo transfers. Per stimulation cycle, patients receiving mild stimulation with a combination of CC and letrozole (study group) versus those with COS (control group) had lower numbers of pre-ovulatory follicles (2.00 ± 1.23 vs. 2.37 ± 1.23, p=0.0066) and oocytes retrieved (1.83 ± 1.17 vs. 2.37 ± 1.23, p=0.0017), and lower follicular output rate (58.6% vs. 68.38%, p=0.0093) and mature oocyte output rate (44.29% vs. 52.88%, p=0.0386) but a higher top-quality metaphase II oocyte ratio (66.7% vs. 54.59%, p=0.0444) and a similar fertilization rate (91.67% vs. 89.04%, p=0.4660). With adjustment for significant between-group baseline differences using multivariable logistic generalized estimating equation model analyses, there was no statistical difference in oocytes retrieved and embryo development between the study and control groups, and insignificant increases in successful pregnancies in the study group were found compared to the control group (i.e., odds ratios [95% CIs]: 1.13 [0.55, 232] and 1.50 [0.65, 3.49] for ongoing pregnancy and live birth, respectively). For POSEIDON Group 4 patients, cotreatment of CC and letrozole in mild stimulation may increase the high-quality oocyte ratio and yield comparable fertilization rate and pregnancy outcomes.