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Recent methodological recommendations suggest the use of the "3-step method," consisting of calendar-based counting, urinary ovulation testing, and serum blood sampling, for the identification of subtle menstrual disturbances (SMDs). However, the use of the 3-step method is not always feasible, so a less demanding combination of calendar-based counting and urinary ovulation testing, that is, the 2-step method, may be a viable alternative. Purpose: To investigate the agreement between the 2- and 3-step methods for the detection of SMDs. Methods: Menstrual cycles (MCs, 98) of 59 athletes were assessed using the 2- and 3-step methods. Regular-length MCs (ie, ≥21 and ≤35 d) were classified as either having no SMD (luteal phase length ≥10 d, midluteal progesterone concentration ≥16 nmol·L−1, and being ovulatory) or having an SMD (eg, short luteal phase [<10 d], inadequate luteal phase [midluteal progesterone concentration <16 nmol·L−1], or being anovulatory). Method agreement was assessed using the McNemar test and Cohen kappa (κ). Results: Substantial agreement was observed between methods (κ =.72; 95% CI,.53–.91), but the 2-step method did not detect all MCs with an SMD, resulting in evidence of systematic bias (χ2 = 5.14; P =.023). The 2-step method detected 61.1% of MCs that had an SMD ([51.4, 70.8]), as verified using the 3-step method, and correctly identified 100% of MCs without an SMD. Conclusions: MCs classified as being disturbed using the 2-step method could be considered valid evidence of SMDs. However, MCs classified without SMDs do not definitively confirm their absence, due to the proven underdetection via the 2-step method. [ABSTRACT FROM AUTHOR]

The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC) use must also be considered given their impact on endogenous sex hormone concentrations and synchronous exogenous profiles. The purpose of this study was to determine if RMR and dual-energy X-ray absorptiometry body composition estimates change across the MC and differ compared with HC users. This was accomplished during a 5-week training camp involving naturally cycling athletes (n = 11) and HC users (n = 7 subdermal progestin implant, n = 4 combined monophasic oral contraceptive pill, n = 1 injection) from the National Rugby League Indigenous Women's Academy. MC phase was retrospectively confirmed via serum estradiol and progesterone concentrations and a positive ovulation test. HC users had serum estradiol and progesterone concentrations assessed at the time point of testing. Results were analyzed using general linear mixed model. There was no effect of MC phase on absolute RMR (p =.877), relative RMR (p =.957), or dual-energy X-ray absorptiometry body composition estimates (p >.05). There was no effect of HC use on absolute RMR (p =.069), relative RMR (p =.679), or fat mass estimates (p =.766), but HC users had a greater fat-free mass and lean body mass than naturally cycling athletes (p =.028). Our findings suggest that RMR and dual-energy X-ray absorptiometry body composition estimates do not significantly differ due to changes in sex hormones in a group of athletes, and measurements can be compared between MC phases or with HC usage without variations in sex hormones causing additional noise. [ABSTRACT FROM AUTHOR]

BACKGROUND: A recent meta-analysis revealed that vagally mediated heart rate variability (vmHRV; a biomarker of emotion regulation capacity) significantly decreases in the luteal phase of the menstrual cycle. As two follow-up studies suggest, these vmHRV decreases are driven primarily by increased luteal progesterone (P4). However, analyses also revealed significant interindividual differences in vmHRV reactivity to the cycle, which is in line with longstanding evidence for interindividual differences in mood sensitivity to the cycle. The present study begins to investigate whether these interindividual differences in vmHRV cyclicity can explain who is at higher risk of showing premenstrual emotional changes. We expected a greater degree of midluteal vmHRV decrease to be predictive of a greater premenstrual increase in negative affect. METHODS: We conducted an observational study with a naturally cycling community sample (N = 31, M = 26.03 years). Over a span of six weeks, participants completed (a) daily ratings of negative affect and (b) counterbalanced lab visits in their ovulatory, midluteal, and perimenstrual phases. Lab visits were scheduled based on positive ovulation tests and included assessments of baseline vmHRV and salivary ovarian steroid levels. RESULTS: In line with previous research, multilevel models suggest that most of the sample shows ovulatory-to-midluteal vmHRV decreases which, however, were not associated with premenstrual emotional changes. Interestingly, it was only the subgroup with luteal increases in vmHRV whose negative affect markedly worsened premenstrually and improved postmenstrually. CONCLUSION: The present study begins to investigate cyclical changes in vmHRV as a potential biomarker of mood sensitivity to the menstrual cycle. The results demonstrate a higher level of complexity in these associations than initially expected, given that only atypical midluteal increases in vmHRV are associated with greater premenstrual negative affect. Potential underlying mechanisms are discussed, among those the possibility that luteal vmHRV increases index compensatory efforts to regulate emotion in those with greater premenstrual negative affect. However, future studies with larger and clinical samples and more granular vmHRV assessments should build on these findings and further explore associations between vmHRV cyclicity and menstrually related mood changes.

Prior research has produced mixed findings regarding whether women feel more attractive during the fertile phase of the menstrual cycle. Here, we analyzed cycle phase and hormonal predictors of women's self-perceived attractiveness (SPA) assessed within a daily diary study. Forty-three women indicated their SPA, sexual desire, and interest in their own partners or other potential mates each day across 1-2 menstrual cycles; saliva samples collected on corresponding days were assayed for estradiol, progesterone, and testosterone; and photos of the women taken at weekly intervals were rated for attractiveness. Contrary to some prior studies, we did not find a significant increase in SPA within the estimated fertile window (i.e., cycle days when conception is possible). However, within-cycle fluctuations in progesterone were significantly negatively associated with shifts in SPA, with a visible nadir in SPA in the mid-luteal phase. Women's sexual desire and SPA were positively associated, and the two variables fluctuated in very similar ways across the cycle. Third-party ratings of women's photos provided no evidence that women's SPA simply tracked actual changes in their visible attractiveness. Finally, for partnered women, changes in SPA correlated with shifts in attraction to own partners at least as strongly as it did with shifts in fantasy about extra-pair partners. Our findings provide preliminary evidence for the idea that SPA is a component of women's sexual motivation that may change in ways similar to other hormonally regulated shifts in motivational priorities. Additional large-scale studies are necessary to test replication of these preliminary findings.

Cyclic fluctuations in hypothalamic-pituitary-gonadal axis (HPG-axis) hormones exert powerful behavioral, structural, and functional effects through actions on the mammalian central nervous system. Yet, very little is known about how these fluctuations alter the structural nodes and information highways of the human brain. In a study of 30 naturally cycling women, we employed multidimensional diffusion and T1-weighted imaging during three estimated menstrual cycle phases (menses, ovulation, and mid-luteal) to investigate whether HPG-axis hormone concentrations co-fluctuate with alterations in white matter (WM) microstructure, cortical thickness (CT), and brain volume. Across the whole brain, 17β-estradiol and luteinizing hormone (LH) concentrations were directly proportional to diffusion anisotropy (μFA; 17β-estradiol: β1 = 0.145, highest density interval (HDI) = [0.211, 0.4]; LH: β1 = 0.111, HDI = [0.157, 0.364]), while follicle-stimulating hormone (FSH) was directly proportional to CT (β1 = 0 .162, HDI = [0.115, 0.678]). Within several individual regions, FSH and progesterone demonstrated opposing relationships with mean diffusivity (Diso) and CT. These regions mainly reside within the temporal and occipital lobes, with functional implications for the limbic and visual systems. Finally, progesterone was associated with increased tissue (β1 = 0.66, HDI = [0.607, 15.845]) and decreased cerebrospinal fluid (CSF; β1 = -0.749, HDI = [-11.604, -0.903]) volumes, with total brain volume remaining unchanged. These results are the first to report simultaneous brain-wide changes in human WM microstructure and CT coinciding with menstrual cycle-driven hormone rhythms. Effects were observed in both classically known HPG-axis receptor-dense regions (medial temporal lobe, prefrontal cortex) and in other regions located across frontal, occipital, temporal, and parietal lobes. Our results suggest that HPG-axis hormone fluctuations may have significant structural impacts across the entire brain.

The field of marine mammal conservation has dramatically benefited from the rapid advancement of methods to assess the reproductive physiology of individuals and populations from steroid hormones isolated from minimally invasive skin-blubber biopsy samples. Historically, this vital information was only available from complete anatomical and physiological investigations of samples collected during commercial or indigenous whaling. Humpback whales (Megaptera novaeangliae) are a migratory, cosmopolitan species that reproduce in warm, low-latitude breeding grounds. New Caledonia is seasonally visited by a small breeding sub-stock of humpback whales, forming part of the endangered Oceania subpopulation. To better understand the demographic and seasonal patterns of reproductive physiology in humpback whales, we quantified baseline measurements of reproductive hormones (progesterone-P4, testosterone-T and 17β-estradiol-E2) using an extensive archive of skin-blubber biopsy samples collected from female humpback whales in New Caledonia waters between 2016 and 2019 (n = 194). We observed significant differences in the P4, T and E2 concentrations across different demographic groups of female humpback whales, and we described some of the first evidence of the endocrine patterns of estrous in live free-ranging baleen whales. This study is fundamental in its methodological approach to a wild species that has a global distribution, with seasonally distinct life histories. This information will assist in monitoring, managing and conserving this population as global ecological changes continue to occur unhindered.

The lipogenesis and steroidogenesis of granulosa cells are crucial during follicular development, yet it remains unclear whether dual-specificity phosphatase 8 ( DUSP8 ) is involved. In this study, the specific role of DUSP8 in lipogenesis and steroidogenesis was investigated through culturing chicken granulosa cells in vitro. The results revealed that the expression levels of adipogenic genes were elevated after DUSP8 overexpression and reduced after knockdown. The same was observed for lipid deposition in granulosa cells. Meanwhile, the steroidogenic gene expression and progesterone synthesis were promoted after DUSP8 overexpression and inhibited after knockdown. In addition, we also found that DUSP8 blocked the phosphorylation of extracellular regulatory kinase 1/2 (ERK1/2). Based on the previous results that activated ERK1/2 signaling inhibited lipid deposition and progesterone synthesis in chicken granulosa cells, we demonstrated that DUSP8 promoted lipid deposition and progesterone synthesis through mediating the ERK1/2 signaling pathway. The results will improve our understanding of the molecular regulatory mechanisms regarding lipid metabolism and progesterone synthesis in chicken granulosa cells. • DUSP8 promotes lipid deposition and progesterone synthesis. • DUSP8 inhibits the activation of ERK1/2 signaling pathway. • DUSP8- attenuated ERK1/2 signaling mediates the functions of granulosa cells. [ABSTRACT FROM AUTHOR]

Objective The primary objective was to determine if vaginal progesterone following cerclage for cervical length <10 mm or cervical dilation in patients without a history of spontaneous preterm birth (sPTB) decreased the risk of preterm birth at <34 weeks' gestation compared with cerclage alone. Secondary objectives were to determine if vaginal progesterone following cerclage (1) decreased the risk of preterm birth at <24, <28, and <37 weeks' gestation and (2) increased the latency period from cerclage placement to delivery compared with treatment with cerclage alone. Study Design Multicenter retrospective cohort study from 2015 to 2020 of singleton pregnancies, without prior sPTB, who had cerclage placement <24 weeks' gestation for cervical length <10 mm or cervical dilation. Exposure defined as cerclage plus vaginal progesterone postoperatively (dual therapy) and unexposed as cerclage alone (monotherapy), based on surgeon preference. Results We included 122 patients, 78 (64%) treated with dual therapy and 44 (36%) treated with monotherapy. In the crude analysis, dual therapy was associated with a lower risk of delivery at <28 weeks' gestation (13%) compared with monotherapy (34%; crude risk ratio: 0.38 [95% confidence interval (CI): 0.19–0.75]). When adjusted for preoperative vaginal progesterone, results were attenuated (adjusted risk ratio: 0.45 [95% CI: 0.20–1.01]). In both the crude and adjusted analyses, the risk of sPTB was not statistically different at <24, <34 or <37 weeks' gestation. Dual therapy was associated with a greater pregnancy latency from cerclage to delivery (16.3 vs. 14.4 weeks; p = 0.04), and greater gestational age at delivery (37.3 vs. 35.8 weeks' gestation; p = 0.02) compared with monotherapy. Conclusion While not statistically significant, the risk of sPTB was lower at all gestational ages studied in patients treated with dual therapy compared with monotherapy. Dual therapy was associated with longer pregnancy latency and greater gestational age at delivery compared with monotherapy. Key Points Dual therapy did not decrease preterm birth risk compared with monotherapy. Dual therapy prolonged pregnancy compared with monotherapy. Dual therapy can be considered but further studies are needed. [ABSTRACT FROM AUTHOR]

Background: The optimal approach to luteal-phase support in infertility treatment remains a subject of debate. This study was conducted to investigate the clinical outcomes, side effects, and patient satisfaction associated with vaginal, subcutaneous, and intramuscular progesterone administration in infertile women undergoing Frozen Embryo Transfer (FET). Methods: This three-armed randomized clinical trial assigned infertile patients eligible for FET to three progesterone treatment groups: vaginal suppositories (400 mg twice daily; n = 100), subcutaneous injections (25 mg daily; n = 102), and intramuscular injections (50 mg daily; n = 108). The primary outcomes were chemical and clinical pregnancy rates per embryo transfer cycle, with chemical pregnancy defined as beta-human chorionic gonadotropin levels > 50 IU/mL two weeks post-transfer and clinical pregnancy confirmed by ultrasound four weeks later. Exploratory outcomes included progesterone-related adverse effects and participant satisfaction, assessed via a Likert-scale survey 12 weeks post-transfer. Statistical analyses included Chi-square tests for categorical data, one-way analysis of variances, and Kruskal–Wallis tests for continuous data. Results: The intramuscular progesterone group had significantly higher chemical pregnancy rates compared to the vaginal and subcutaneous groups (41.7% vs. 26.0% and 27.5%, respectively; p = 0.026). Although the clinical pregnancy rate was also higher in the intramuscular group (32.4%) compared to the vaginal (23.0%) and subcutaneous groups (21.6%), this difference was not statistically significant (p = 0.148). Additionally, patient satisfaction was greater with vaginal and subcutaneous applications than with intramuscular injections (p < 0.001), likely due to a significantly higher incidence of side effects, such as pain and edema at the injection site, in the intramuscular group (p < 0.001). Conclusions: We found that intramuscular progesterone resulted in higher chemical pregnancy rates than vaginal or subcutaneous routes, but this did not translate into higher clinical pregnancy rates. Despite its effectiveness, intramuscular administration was associated with more adverse effects and lower patient satisfaction. Future research should explore optimizing progesterone regimens to balance efficacy and patient comfort. Trial registration: The trial protocol was registered on December 6, 2020, in the Iranian Registry of Clinical Trials (IRCT), a primary registry in the World Health Organization (WHO) Registry Network, under the registration number IRCT20141217020351N12. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the relationship between phthalates exposure and estrogen and progesterone levels, as well as their role in late-onset preeclampsia. Methods: A total of 60 pregnant women who met the inclusion and exclusion criteria were recruited. Based on the diagnosis of preeclampsia, participants were divided into two groups: normotensive pregnant women (n = 30) and pregnant women with late-onset preeclampsia (n = 30). The major metabolites of phthalates (MMP, MEP, MiBP, MBP, MEHP, MEOHP, MEHHP) and sex steroid hormones (estrogen and progesterone) were quantified in urine samples of the participants. Results: No significant differences were observed in the levels of MMP, MEP, MiBP, MBP, MEHP, MEOHP, and MEHHP between women with preeclampsia and normotensive pregnant women (P > 0.05). The urinary estrogen showed a negative correlation with systolic blood pressure (rs= -0.46, P < 0.001) and diastolic blood pressure (rs= -0.47, P < 0.001). Additionally, the urinary estrogen and progesterone levels were lower in women with preeclampsia compared to those in normotensive pregnant women (P < 0.05). After adjusting for confounding factors, we observed a significant association between reduced urinary estrogen levels and an increased risk of preeclampsia (aOR = 0.09, 95%CI = 0.02–0.46). Notably, in our decision tree model, urinary estrogen emerged as the most crucial variable for identifying pregnant women at a high risk of developing preeclampsia. A positive correlation was observed between urinary progesterone and MEHP (rs = 0.36, P < 0.05) in normotensive pregnant women. A negative correlation was observed between urinary estrogen and MEP in pregnant women with preeclampsia (rs= -0.42, P < 0.05). Conclusions: Phthalates exposure was similar in normotensive pregnant women and those with late-onset preeclampsia within the same region. Pregnant women with preeclampsia had lower levels of estrogen and progesterone in their urine, while maternal urinary estrogen was negatively correlated with the risk of preeclampsia and phthalate metabolites (MEP). Trial registration: Registration ID in Clinical Trials: NCT04369313; registration date: 30/04/2020. [ABSTRACT FROM AUTHOR]

Background: Understanding individual ovarian hormone cycles and their relationship with health, performance and injuries is highly important to practitioners supporting female athletes. Venous blood sampling is the current gold standard for measuring the ovarian hormones, but the invasive nature of this method presents a major barrier in sport environments. Saliva analysis may offer an alternative method as it is non-invasive, allowing the sample to be collected "in situ", with relative ease, necessary in applied sport environments. Objective: The aims of this study were: (i) To compare the concentration of progesterone between capillary blood and saliva, (ii) To assess the efficacy of weekly measurements of progesterone for determining if ovulation has occurred in elite eumenorrheic football players, and (iii) To establish a saliva criteria cut-off for establishing ovulation and assessing the sensitivity, specificity and accuracy values of the method. Methodology: Twenty-one professional and semi-professional, Spanish league female football players (18.6 ± 1.5 years, 58.1 ± 6.0 kg, 164.0 ± 4.8 cm) with natural menstrual cycles, completed the study. Capillary blood and saliva samples were collected from each participant on twelve occasions each separated by at least 7 days. All samples were collected in the morning, following an overnight fast. Results: According to luteal phase serum progesterone concentrations, 11 out of 21 (52%) players presented with menstrual irregularities (oligomenorrheic n=6, anovulatory n = 4, amenorrhoeic n = 1). A significant correlation was observed between plasma and saliva progesterone in the estimated eumenorrheic group (r = 0.80, p = <0.001, 95% CI 0.72--0.86). The association between serum and saliva progesterone was weaker in the oligomenorrheic group (r = 0.47, p = <0.001, 95% CI 0.27--0.64) and was not present in the anovulatory or amenorrhoeic groups. Conclusions: Salivary measurements of progesterone are well correlated with capillary blood when taken during eumenorrheic menstrual cycles and presents a viable, non-invasive method of establishing characteristic progesterone fluctuations in applied sport settings. The strength of the association appears to be concentration dependent. A luteal phase saliva progesterone (P4) >50 pg/ml and >1.5x follicular baseline has good sensitivity, specificity, and accuracy to indicate ovulation compared to established criteria for serum progesterone. [ABSTRACT FROM AUTHOR]

Gender‐affirming hormone therapy (GAHT) is used by many transgender and gender‐diverse adults to align physical characteristics with their gender identity, reduce gender incongruence and improve psychological functioning. This narrative review provides an overview of the initiation and monitoring of GAHT in an Australian context. Trans individuals treated with testosterone typically receive standard testosterone doses and formulations recommended for cisgender men, whereas those receiving estradiol GAHT are typically treated with estradiol in combination with an anti‐androgen in those without orchidectomy. Proactive monitoring and mitigation of cardiovascular risk factors is pertinent in all transgender and gender‐diverse adults and bone health is an important consideration in those using estradiol GAHT. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effect of the MC and endogenous sex hormone concentrations on performance-determining variables in three distinctMC phases in endurance-trained females. Methods: Twenty-one eumenorrheic trained/highly trained endurance athletes completed a standardized test battery during the early follicular phase (EFP), ovulatory phase (OP), and midluteal phase (MLP) for either one (n = 7) or two test cycles (n = 14). MC phases were determined using calendar-based counting, urinary ovulation testing, and verified with serum hormone analysis. MCs were retrospectively classified as eumenorrheic or disturbed. Disturbed MCs were excluded from analysis. The test battery consisted of 4-6 x 5-min submaximal stages with stepwise speed increases, a 30-s all-out double-poling ski ergometer test, and a maximal incremental treadmill running test. Results: At a group level, there was no effect of MC phase or the serum concentrations of estrogen and progesterone on peak oxygen uptake (...), oxygen uptake at 4 mmol⋅L-1 blood lactate concentration, time to exhaustion, running economy, or mean 30-s power output (MPO30s). Serum testosterone concentration was positively associated with MPO30s (P = 0.016). Changes in ... from EFP to MLP were inconsistent between individuals and across cycles. Conclusions: None of the measured performance-determining variables were influenced by MC phase or serumestrogen or progesterone concentrations. Although some individual patterns could be observed, there was no indication that any single MC phase is consistently associated with improved or impaired ... on a group level. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to evaluate the effect on reproductive performance of a targeted reproductive management (TRM) program for first postpartum insemination (AI) that prioritized AI at detected estrus (AIE) by providing different intervals for estrus detection based on records of automated estrus alerts (AEA) during the voluntary waiting period (VWP). A secondary objective was to evaluate the association between occurrence of AEA during the VWP and reproductive performance. Lactating Holstein cows (n = 1,260) fitted with neck behavior monitoring sensors for detection of estrus were randomly assigned to a program that used all-timed AI (TAI) for first service (ALL-TAI ; n = 632) or a TRM program that prioritized AIE and used TAI only for cows not detected in estrus (TP-AIE ; n = 628). Cows in the ALL-TAI treatment received TAI at 76 ± 3 days in milk (DIM) after a Double-Ovsynch protocol. Cows in the TP-AIE treatment were eligible for AIE for 30 ± 3 or 16 ± 3 d after a 49 d VWP if at least one (n = 346) or no (n = 233) AEA were recorded from 15 to 49 DIM. Cows not AIE received TAI after an Ovsynch protocol with progesterone supplementation at 90 ± 3 or 76 ± 3 DIM if the cow had or did not have AEA during the VWP, respectively. Data were analyzed by logistic and Cox's proportional hazard regression. In the TP-AIE treatment, 69.3 % of cows received AIE and more cows with (83.3 %) than without (45.0 %) AEA during the VWP received AIE. Cows in the TP-AIE (69.0 ± 0.7 d) treatment had fewer days from calving to first AI than cows in the ALL-TAI (75.7 ± 0.8 d) treatment. The proportion of cows pregnant by 150 DIM (ALL-TAI = 59.1 % and TP-AIE = 56.0 %) and the hazard ratio (HR) for time to pregnancy (1.0 [95 % confidence interval: 0.9, 1.2]) did not differ between treatments and median days to pregnancy were 102 and 107 for the ALL-TAI and TP-AIE treatments, respectively. Overall, the ALL-TAI (42.3 %) treatment had more first service pregnancies per AI (P/AI) than the TP-AIE (29.0 %) treatment. Cows with AEA during the VWP had greater P/AI (42.5 % vs. 28.9 %), proportion of cows pregnant by 150 DIM (67.4 % vs. 47.0 %), and HR for time to pregnancy (1.6 [1.4, 1.9]) than cows without AEA during the VWP. We conclude that a TRM program that prioritized AIE based on AEA during the VWP led to a similar pregnancy rate and proportion of cows pregnant by mid-lactation than a program that used all-TAI with extended VWP despite fewer P/AI to first service. Also, expression of estrus during the VWP was associated with improved reproductive performance. Thus, AEA during the VWP could be used as a predictor of reproductive potential for TRM of lactating dairy cows. • Prioritizing AIE services based on AEA during the VWP optimized management. • Targeted management based on AEA had similar performance than an all-TAI program. • Expression of estrus during the VWP was associated with improved performance. • Estrus alerts during the VWP are a good predictor of reproductive performance. [ABSTRACT FROM AUTHOR]

Background: Females are considered to have an increased susceptibility to neuromyelitis optica spectrum disorder (NMOSD) than males, especially aquaporin-4 (AQP4) antibody positive NMOSD, indicating that sex hormones may be involved in the NMOSD pathogenesis. However, the causality between sex hormones and NMOSD still remains unclear. Methods: Based on the genome-wide association study (GWAS) data of three sex hormones (estradiol (E2), progesterone (PROG) and bioavailable testosterone (BAT)), sex hormone-binding globulin (SHBG), age of menarche, age of menopause, and NMOSD (total, AQP4 + and AQP4 −), we performed a two-sample bidirectional Mendelian randomization (MR) study. Sex-stratified GWAS data of E2, PROG, BAT, and SHBG was obtained for gender-specific MR analysis. Causal inferences were based on the inverse variance weighted method, MR-Egger regression, and weighted median method. The reverse MR analysis was also performed to assess the impact of NMOSD on hormone levels. Results: PROG in females had aggravative effects on NMOSD (P < 0.001), especially AQP4 − NMOSD (P < 0.001). In the reverse MR analysis, total NMOSD was found to decrease the level of BAT (P < 0.001) and increase the level of SHBG (P = 0.001) in females. Conclusion: Findings of this MR analysis revealed mutual causal associations between sex hormones and NMOSD, which provided novel perspectives about the gender-related pathogenesis of NMOSD. [ABSTRACT FROM AUTHOR]