Kisspeptin in functional hypothalamic amenorrhea: Pathophysiology and therapeutic potential.

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea, resulting in anovulation and infertility, and is a low estrogen state that increases the risk of cardiovascular disease and impairs bone health. FHA is characterized by acquired suppression of physiological pulsatile gonadotropin-releasing hormone (GnRH) release by the hypothalamus in the absence of an identifiable structural cause, resulting in a functional hypogonadotropic hypogonadism. FHA results from either decreased energy intake and/or excessive exercise, leading to low energy availability and weight loss-often in combination with psychological stress on top of a background of genetic susceptibility. The hypothalamic neuropeptide kisspeptin is a key component of the GnRH pulse generator, tightly regulating pulsatile GnRH secretion and the downstream reproductive axis. Here, we review the physiological regulation of pulsatile GnRH secretion by hypothalamic kisspeptin neurons and how their activity is modulated by signals of energy status to affect reproductive function. We explore endocrine factors contributing to the suppression of GnRH pulsatility in the pathophysiology of FHA and how hypothalamic kisspeptin neurons likely represent a final common pathway through which these factors affect GnRH pulse generation. Finally, we discuss the therapeutic potential of kisspeptin as a novel treatment for women with FHA.

Interactions between kisspeptin and bone: Cellular mechanisms, clinical evidence, and future potential.

The neuropeptide kisspeptin and its cognate receptor have been extensively studied in reproductive physiology, with diverse and well-established functions, including as an upstream regulator of pubertal onset, reproductive hormone secretion, and sexual behavior. Besides classical reproduction, both kisspeptin and its receptor are extensively expressed in bone-resorbing osteoclasts and bone-forming osteoblasts, which putatively permits direct bone effects. Accordingly, this sets the scene for recent compelling findings derived from in vitro experiments through to in vivo and clinical studies revealing prominent regulatory interactions for kisspeptin signaling in bone metabolism, as well as certain oncological aspects of bone metabolism. Herein, we comprehensively examine the experimental evidence obtained to date supporting the interaction between kisspeptin and bone. A comprehensive understanding of this emerging facet of kisspeptin biology is fundamental to exploiting the future therapeutic potential of kisspeptin-based medicines as a novel strategy for treating bone-related disorders.

Astrocytes: a star emerges in the control of reproductive hormones.

Kisspeptin is an essential neuropeptide sitting at the apex of the hypothalamo-pituitary-gonadal (HPG) endocrine axis to regulate gonadotropin-releasing hormone (GnRH) neurons and downstream reproductive hormones. Kisspeptin neurons integrate feedback from sex steroids facilitating regulation of the menstrual cycle and mediate the effects of metabolic stressors on the reproductive axis. In this issue of the JCI, Torres and colleagues describe another pathway for kisspeptin signaling in astrocytes to influence GnRH neuronal output. Astrocytes had kisspeptin receptors that activated canonical intracellular signaling pathways to constrain the magnitude of kisspeptin-induced GnRH neuronal stimulation. Additionally, the appositions between kisspeptin and GnRH neurons were dynamic during the ovarian cycle, with astrocyte kisspeptin signaling proposed as a putative modulator of this neuroplasticity. Importantly, astrocyte kisspeptin signaling also mediated susceptibility to metabolic stressors and the development of obesity-induced hypogonadism, underscoring the physiological and pathological importance of this pathway and revealing the importance of nonneuronal signaling in reproductive health.

Biomarkers to inform the management of polycystic ovary syndrome: A review of systematic reviews.

INTRODUCTION: Polycystic ovarian syndrome (PCOS) is the commonest endocrine condition affecting reproductive age women. Many biomarkers may aid assessment and management, however evidence is limited on their utility in clinical practice. We conducted a review of systematic reviews to identify the most useful biomarkers in the clinical management of PCOS. METHODS: We searched MEDLINE, EMBASE, CENTRAL and HTA until August 2023 for reviews evaluating biomarkers in PCOS women compared to healthy controls. Methodological quality was assessed using the AMSTAR2 tool. We reported pooled evidence for each biomarker with 95% confidence intervals from the most recent, up-to-date, and best quality review. RESULTS: From 3360 citations, we included 75 systematic reviews (88 biomarkers, 191,792 women). Most reviews (50/75, 67%) were moderate quality, but reported high heterogeneity (66/75, 88%). We identified 63 abnormal biomarkers in women with PCOS versus healthy controls. Of these, 22 core biomarkers could help evaluate the multisystemic impact of PCOS and inform patient management and surveillance: dehydroepiandrosterone, prolactin, sex hormone-binding globulin, total and free testosterone, anti-Mullerian hormone, systolic and diastolic blood pressure, c-reactive protein, fibrinogen, oral glucose tolerance test, homoeostatic model assessment-insulin resistance index, fasting insulin, total cholesterol, triglycerides, lipoprotein(a), HDL, LDL, non-HDL-cholesterol, ferritin, iron, and 25-hydroxy-vitamin D. CONCLUSION: We identified 22 core biomarkers assessing the multisystemic impact of PCOS and inform its clinical management. Future research is required to establish validated healthcare pathways.

Factors affecting shared decision-making concerning menopausal hormone therapy.

Menopausal hormone therapy (MHT) is an effective treatment for menopause-related symptoms. Menopause management guidelines recommend a personalized approach to menopause care, including MHT use. Decision-making around menopause care is a complex, iterative process influenced by multiple factors framed by perspectives from both women and healthcare providers (HCPs). This narrative review aims to summarize evidence around factors affecting decision-making regarding menopause-related care. For HCPs, the provision of individualized risk estimates is challenging in practice given the number of potential benefits and risks to consider, and the complexity of the data available, especially within time-limited consultations. Women seeking menopause care have the difficult task of making sense of the benefit versus risk profiles to make choices in line with their decisional needs influenced by sociocultural/economic, educational, demographic, and personal characteristics. The press, social media, and influential celebrities also impact the perception of menopause and decision-making around it. Understanding these factors can lead to improved participation in shared decision-making, satisfaction with the decision and decision-making process, adherence to treatment, reduced decisional regret, efficient use of resources, and ultimately long-term satisfaction with care.

Women and men with distressing low sexual desire exhibit sexually dimorphic brain processing.

Distressing low sexual desire, termed Hypoactive Sexual Desire Disorder (HSDD), affects approximately 10% of women and 8% of men. In women, the 'top-down' theory of HSDD describes hyperactivity in higher-level cognitive brain regions, suppressing lower-level emotional/sexual brain areas. However, it is unknown how this neurofunctional disturbance compares to HSDD in men. To investigate this, we employed task-based functional MRI in 32 women and 32 men with HSDD to measure sexual-brain processing during sexual versus non-sexual videos, as well as psychometric questionnaires to assess sexual desire/arousal. We demonstrate that women had greater activation in higher-level and lower-level brain regions, compared to men. Indeed, women who had greater hypothalamic activation in response to sexual videos, reported higher psychometric scores in the evaluative (r = 0.55, P = 0.001), motivational (r = 0.56, P = 0.003), and physiological (r = 0.57, P = 0.0006) domains of sexual desire and arousal after watching the sexual videos in the scanner. By contrast, no similar correlations were observed in men. Taken together, this is the first direct comparison of the neural correlates of distressing low sexual desire between women and men. The data supports the 'top-down' theory of HSDD in women, whereas in men HSDD appears to be associated with different neurofunctional processes.

Bariatric surgery for spontaneous ovulation in women living with polycystic ovary syndrome: the BAMBINI multicentre, open-label, randomised controlled trial.

BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. Obesity exacerbates the reproductive complications of PCOS; however, the management of obesity in women with PCOS remains a large unmet clinical need. Observational studies have indicated that bariatric surgery could improve the rates of ovulatory cycles and prospects of fertility; however, the efficacy of surgery on ovulation rates has not yet been compared with behavioural modifications and medical therapy in a randomised trial. The aim of this study was to compare the safety and efficacy of bariatric surgery versus medical care on ovulation rates in women with PCOS, obesity, and oligomenorrhoea or amenorrhoea. METHODS: In this multicentre, open-label, randomised controlled trial, 80 women older than 18 years, with a diagnosis of PCOS based on the 2018 international evidence-based guidelines for assessing and managing PCOS, and a BMI of 35 kg/m2 or higher, were recruited from two specialist obesity management centres and via social media. Participants were randomly assigned at a 1:1 ratio to either vertical sleeve gastrectomy or behavioural interventions and medical therapy using a computer-generated random sequence (PLAN procedure in SAS) by an independent researcher not involved with any other aspect of the clinical trial. The median age of the entire cohort was 31 years and 79% of participants were White. The primary outcome was the number of biochemically confirmed ovulatory events over 52 weeks, and was assessed using weekly serum progesterone measurements. The primary endpoint included the intention-to-treat population and safety analyses were per-protocol population. This study is registered with the ISRCTN registry (ISRCTN16668711). FINDINGS: Participants were recruited from Feb 20, 2020 to Feb 1, 2021. 40 participants were assigned to each group and there were seven dropouts in the medical group and ten dropouts in the surgical group. The median number of ovulations was 6 (IQR 3·5-10·0) in the surgical group and 2 (0·0-4·0) in the medical group. Women in the surgical group had 2.5 times more spontaneous ovulations compared with the medical group (incidence rate ratio 2·5 [95% CI 1·5-4·2], p<0·0007). There were more complications in the surgical group than the medical group, although without long-term sequelae. There were 24 (66·7%) adverse events in the surgical group and 12 (30·0%) in the medical group. There were no treatment-related deaths. INTERPRETATION: Bariatric surgery was more effective than medical care for the induction of spontaneous ovulation in women with PCOS, obesity, and oligomenorrhoea or amenorrhoea. Bariatric surgery could, therefore, enhance the prospects of spontaneous fertility in this group of women. FUNDING: The Jon Moulton Charity Trust.

Current Challenges and Future Directions in the Assessment of Glucocorticoid Status.

Glucocorticoid hormones (GC) are secreted in a circadian and ultradian rhythm and play a critical role in maintaining physiological homeostasis, with both excess and insufficient GC associated with adverse effects on health. Current assessment of GC status is primarily clinical, often in conjunction with serum cortisol values, which may be stimulated or suppressed depending on the GC disturbance being assessed. In the setting of extreme perturbations in cortisol levels i.e. markedly low or high levels, symptoms and signs of GC dysfunction may be overt. However, when disturbances in cortisol GC status values are less extreme, such as when assessing optimization of a GC replacement regimen, signs and symptoms can be more subtle or non-specific. Current tools for assessing GC status, are best suited to identifying profound disturbances but may lack sensitivity for confirming optimal GC status. Moreover, single cortisol values do not necessarily reflect an individual's GC status, as they are subject to inter- and intra-individual variation, do not take into account the pulsatile nature of cortisol secretion, variation in binding proteins, or local tissue concentrations as dictated by 11ßeta-hydroxysteroid dehydrogenase (11ß-HSD) activity, as well as GC receptor sensitivity. In the present review, we evaluate possible alternative methods for the assessment of GC status that do not solely rely on measurement of circulating cortisol levels. We discuss the potential of changes in metabolomic profiles, miRNA, gene expression, epigenetic, and other novel biomarkers such as GDF-15 and osteocalcin, that could in future aid in the objective classification of GC status.

The prospect of artificial intelligence to personalize assisted reproductive technology.

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

Healthcare and research priorities for women with polycystic ovary syndrome in the UK National Health Service: A modified Delphi method.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is a chronic lifelong condition affecting up to 20% of women worldwide. There is limited input from affected women to guide the provision of healthcare services and future research needs. Our objective was to scope the healthcare and research priorities of women with PCOS in the United Kingdom. DESIGN: A three-staged modified Delphi method, consisting of two questionnaires and a consensus meeting involving lay representatives and healthcare professionals. PATIENTS AND MEASUREMENTS: Lay patient representatives of women with PCOS. Participants were asked to identify and rank healthcare and research priorities for their importance. RESULTS: Six hundred and twenty-four lay participants took part in our Delphi method. Over 98% were diagnosed with PCOS (614/624, 98.4%). More than half experienced difficulties to receive a PCOS diagnosis (375/624, 60%), and the majority found it difficult to access specialised PCOS health services in the NHS (594/624, 95%). The top two healthcare priorities included better education for health professionals on the diagnosis and management of PCOS (238/273, 87.1%) and the need to set up specialist PCOS services (234/273, 85.7%). The top two research priorities focused on identifying better treatments for irregular periods (233/273, 85.3%) followed by better tests for early PCOS diagnosis (230/273, 84.2%). CONCLUSIONS: We identified 13 healthcare and 14 research priorities that reflect the current health needs of women with PCOS in the United Kingdom. Adopting these priorities in future healthcare and research planning will help to optimise the health of women with PCOS and increase patient satisfaction.

HormoneBayes: A novel Bayesian framework for the analysis of pulsatile hormone dynamics.

The hypothalamus is the central regulator of reproductive hormone secretion. Pulsatile secretion of gonadotropin releasing hormone (GnRH) is fundamental to physiological stimulation of the pituitary gland to release luteinizing hormone (LH) and follicle stimulating hormone (FSH). Furthermore, GnRH pulsatility is altered in common reproductive disorders such as polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA). LH is measured routinely in clinical practice using an automated chemiluminescent immunoassay method and is the gold standard surrogate marker of GnRH. LH can be measured at frequent intervals (e.g., 10 minutely) to assess GnRH/LH pulsatility. However, this is rarely done in clinical practice because it is resource intensive, and there is no open-access, graphical interface software for computational analysis of the LH data available to clinicians. Here we present hormoneBayes, a novel open-access Bayesian framework that can be easily applied to reliably analyze serial LH measurements to assess LH pulsatility. The framework utilizes parsimonious models to simulate hypothalamic signals that drive LH dynamics, together with state-of-the-art (sequential) Monte-Carlo methods to infer key parameters and latent hypothalamic dynamics. We show that this method provides estimates for key pulse parameters including inter-pulse interval, secretion and clearance rates and identifies LH pulses in line with the widely used deconvolution method. We show that these parameters can distinguish LH pulsatility in different clinical contexts including in reproductive health and disease in men and women (e.g., healthy men, healthy women before and after menopause, women with HA or PCOS). A further advantage of hormoneBayes is that our mathematical approach provides a quantified estimation of uncertainty. Our framework will complement methods enabling real-time in-vivo hormone monitoring and therefore has the potential to assist translation of personalized, data-driven, clinical care of patients presenting with conditions of reproductive hormone dysfunction.

Quantifying the variability in the assessment of reproductive hormone levels.

OBJECTIVE: To quantify how representative a single measure of reproductive hormone level is of the daily hormonal profile using data from detailed hormonal sampling in the saline placebo-treated arm conducted over several hours. DESIGN: Retrospective analysis of data from previous interventional research studies evaluating reproductive hormones. SETTING: Clinical Research Facility at a tertiary reproductive endocrinology centre at Imperial College Hospital NHS Foundation Trust. PATIENTS: Overall, 266 individuals, including healthy men and women (n = 142) and those with reproductive disorders and states (n = 124 [11 with functional hypothalamic amenorrhoea, 6 with polycystic ovary syndrome, 62 women and 32 men with hypoactive sexual desire disorder, and 13 postmenopausal women]), were included in the analysis. INTERVENTIONS: Data from 266 individuals who had undergone detailed hormonal sampling in the saline placebo-treated arms of previous research studies was used to quantify the variability in reproductive hormones because of pulsatile secretion, diurnal variation, and feeding using coefficient of variation (CV) and entropy. MAIN OUTCOME MEASURES: The ability of a single measure of reproductive hormone level to quantify the variability in reproductive hormone levels because of pulsatile secretion, diurnal variation, and nutrient intake. RESULTS: The initial morning value of reproductive hormone levels was typically higher than the mean value throughout the day (percentage decrease from initial morning measure to daily mean: luteinizing hormone level 18.4%, follicle-stimulating hormone level 9.7%, testosterone level 9.2%, and estradiol level 2.1%). Luteinizing hormone level was the most variable (CV 28%), followed by sex-steroid hormone levels (testosterone level 12% and estradiol level 13%), whereas follicle-stimulating hormone level was the least variable reproductive hormone (CV 8%). In healthy men, testosterone levels fell between 9:00 am and 5:00 pm by 14.9% (95% confidence interval 4.2, 25.5%), although morning levels correlated with (and could be predicted from) late afternoon levels in the same individual (r2 = 0.53, P<.0001). Testosterone levels were reduced more after a mixed meal (by 34.3%) than during ad libitum feeding (9.5%), after an oral glucose load (6.0%), or an intravenous glucose load (7.4%). CONCLUSION: Quantification of the variability of a single measure of reproductive hormone levels informs the reliability of reproductive hormone assessment.

Endocrine profile of the kisspeptin receptor agonist MVT-602 in healthy premenopausal women with and without ovarian stimulation: results from 2 randomized, placebo-controlled clinical tricals.

BACKGROUND: Kisspeptin is an essential regulator of hypothalamic gonadotropin-releasing hormone release and is required for physiological ovulation. Native kisspeptin-54 can induce oocyte maturation during in vitro fertilization treatment, including in women who are at high risk of ovarian hyperstimulation syndrome. MVT-602 is a potent kisspeptin receptor agonist with prospective utility to treat anovulatory disorders by triggering oocyte maturation and ovulation during medically assisted reproduction (MAR). Currently, the endocrine profile of MVT-602 during ovarian stimulation is unreported. OBJECTIVE: To determine the endocrine profile of MVT-602 in the follicular phase of healthy premenopausal women (phase-1 trial), and after minimal ovarian stimulation to more closely reflect the endocrine milieu encountered during MAR (phase-2a trial). DESIGN: Two randomized, placebo-controlled, parallel-group, dose-finding trials. SETTING: Clinical trials unit. PATIENTS: Healthy women aged 18-35 years, either without (phase-1; n = 24), or with ovarian stimulation (phase-2a; n = 75). INTERVENTIONS: Phase-1: single subcutaneous dose of MVT-602 (0.3, 1.0, or 3.0 µg) or placebo, (n = 6 per dose). Phase-2a: single subcutaneous dose of MVT-602 (0.1, 0.3, 1.0, or 3.0 µg; n = 16-17 per dose), triptorelin 0.2 mg (n = 5; active comparator), or placebo (n = 5). MAIN OUTCOME MEASURES: Phase-1: safety/tolerability; pharmacokinetics; and pharmacodynamics (luteinizing hormone [LH] and other reproductive hormones). Phase-2a: safety/tolerability; pharmacokinetics; pharmacodynamics (LH and other reproductive hormones); and time to ovulation assessed by transvaginal ultrasound. RESULTS: In both the trials, MVT-602 was safe and well tolerated across the entire dose range. It was rapidly absorbed and eliminated, with a mean elimination half-life of 1.3-2.2 hours. In the phase-2a trial, LH concentrations increased dose dependently; mean maximum change from baseline of 82.4 IU/L at 24.8 hours was observed after administration of 3 µg MVT-602 and remained >15 IU/L for 33 hours. Time to ovulation after drug administration was 3.3-3.9 days (MVT-602), 3.4 days (triptorelin), and 5.5 days (placebo). Ovulation occurred within 5 days of administration in 100% (3 µg), 88% (1 µg), 82% (0.3 µg), and 75% (0.1 µg), of women after MVT-602, 100% after triptorelin and 60% after placebo. CONCLUSIONS: MVT-602 induces LH concentrations of similar amplitude and duration as the physiological midcycle LH surge with potential utility for induction of oocyte maturation and ovulation during MAR. CLINICAL TRIAL REGISTRATION NUMBER: EUDRA-CT: 2017-003812-38, 2018-001379-20.

Obesity-Related Hypogonadism in Women.

Obesity-related hypogonadotropic hypogonadism is a well-characterized condition in men (termed male obesity-related secondary hypogonadism; MOSH); however, an equivalent condition has not been as clearly described in women. The prevalence of polycystic ovary syndrome (PCOS) is known to increase with obesity, but PCOS is more typically characterized by increased gonadotropin-releasing hormone (GnRH) (and by proxy luteinizing hormone; LH) pulsatility, rather than by the reduced gonadotropin levels observed in MOSH. Notably, LH levels and LH pulse amplitude are reduced with obesity, both in women with and without PCOS, suggesting that an obesity-related secondary hypogonadism may also exist in women akin to MOSH in men. Herein, we examine the evidence for the existence of a putative non-PCOS "female obesity-related secondary hypogonadism" (FOSH). We précis possible underlying mechanisms for the occurrence of hypogonadism in this context and consider how such mechanisms differ from MOSH in men, and from PCOS in women without obesity. In this review, we consider relevant etiological factors that are altered in obesity and that could impact on GnRH pulsatility to ascertain whether they could contribute to obesity-related secondary hypogonadism including: anti-Müllerian hormone, androgen, insulin, fatty acid, adiponectin, and leptin. More precise phenotyping of hypogonadism in women with obesity could provide further validation for non-PCOS FOSH and preface the ability to define/investigate such a condition.

The Emerging Therapeutic Potential of Kisspeptin and Neurokinin B.

Kisspeptin (KP) and neurokinin B (NKB) are neuropeptides that govern the reproductive endocrine axis through regulating hypothalamic gonadotropin-releasing hormone (GnRH) neuronal activity and pulsatile GnRH secretion. Their critical role in reproductive health was first identified after inactivating variants in genes encoding for KP or NKB signaling were shown to result in congenital hypogonadotropic hypogonadism and a failure of pubertal development. Over the past 2 decades since their discovery, a wealth of evidence from both basic and translational research has laid the foundation for potential therapeutic applications. Beyond KP's function in the hypothalamus, it is also expressed in the placenta, liver, pancreas, adipose tissue, bone, and limbic regions, giving rise to several avenues of research for use in the diagnosis and treatment of pregnancy, metabolic, liver, bone, and behavioral disorders. The role played by NKB in stimulating the hypothalamic thermoregulatory center to mediate menopausal hot flashes has led to the development of medications that antagonize its action as a novel nonsteroidal therapeutic agent for this indication. Furthermore, the ability of NKB antagonism to partially suppress (but not abolish) the reproductive endocrine axis has supported its potential use for the treatment of various reproductive disorders including polycystic ovary syndrome, uterine fibroids, and endometriosis. This review will provide a comprehensive up-to-date overview of the preclinical and clinical data that have paved the way for the development of diagnostic and therapeutic applications of KP and NKB.

New advances in menopause symptom management.

Vasomotor symptoms (VMS) are characteristic of menopause experienced by over 75% of postmenopausal women with significant health and socioeconomic implications. Although the average duration of symptoms is seven years, 10% of women experience symptoms for more than a decade. Although menopausal hormone therapy (MHT) remains an efficacious and cost-effective treatment, its use may not be suitable in all women, such as those at an increased risk of breast cancer or gynaecological malignancy. The neurokinin B (NKB) signaling pathway, together with its intricate connection to the median preoptic nucleus (MnPO), has been postulated to provide integrated reproductive and thermoregulatory responses, with a central role in mediating postmenopausal VMS. This review describes the physiological hypothalamo-pituitary-ovary (HPO) axis, and subsequently the neuroendocrine changes that occur with menopause using evidence derived from animal and human studies. Finally, data from the latest clinical trials using novel therapeutic agents that antagonise NKB signaling are reviewed.

Luteal phase support in assisted reproductive technology.

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

Factors predicting normalization of reproductive hormones after cessation of anabolic-androgenic steroids in men: a single center retrospective study.

OBJECTIVE: Symptomatic hypogonadism discourages men from stopping anabolic-androgenic steroids (AAS). Some men illicitly take drugs temporarily stimulating endogenous testosterone following AAS cessation (post-cycle therapy; PCT) to lessen hypogonadal symptoms. We investigated whether prior PCT use was associated with the normalization of reproductive hormones following AAS cessation. METHODS: Retrospective analysis of 641 men attending a clinic between 2015-2022 for a single, nonfasting, random blood test <36 months following AAS cessation, with or without PCT. Normalized reproductive hormones (ie, a combination of reference range serum luteinizing hormone, follicle-stimulating hormone, and total testosterone levels) were the surrogate marker of biochemical recovery. RESULTS: Normalization of reproductive hormones was achieved in 48.2% of men. PCT use was associated with faster biochemical recovery (13.0 (IQR8.0-19.0) weeks, PCT; 26.0 (IQR10.5-52) weeks, no-PCT; P < .001). Odds of biochemical recovery during multivariable analysis were: (1) higher with PCT (OR3.80) vs no-PCT (P = .001), in men stopping AAS ≤3 months previously; (2) reduced when 2 (OR0.55), 3 (OR0.46), or 4 (OR0.25) AAS were administered vs 1 drug (P = .009); (3) lower with AAS >6 vs ≤3 months previously (OR0.34, P = .01); (4) higher with last reported AAS >3 months (OR 5.68) vs ≤3 months (P = .001). PCT use was not associated with biochemical recovery in men stopping AAS >3 months previously. CONCLUSION: Without evidence-based withdrawal protocols, men commonly try avoiding post-AAS hypogonadism with PCT, which is illicit, ill-defined, and not recommended. Only half of men had complete biochemical testicular recovery after stopping AAS. The surprising association of self-reported PCT use with short-term biochemical recovery from AAS-induced hypogonadism warrants further investigation.