Mechanisms of Regeneration and Fibrosis in the Endometrium.

The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.

Physiology of the Endometrium and Regulation of Menstruation.

The physiological functions of the uterine endometrium (uterine lining) are preparation for implantation, maintenance of pregnancy if implantation occurs, and menstruation in the absence of pregnancy. The endometrium thus plays a pivotal role in reproduction and continuation of our species. Menstruation is a steroid-regulated event, and there are alternatives for a progesterone-primed endometrium, i.e., pregnancy or menstruation. Progesterone withdrawal is the trigger for menstruation. The menstruating endometrium is a physiological example of an injured or "wounded" surface that is required to rapidly repair each month. The physiological events of menstruation and endometrial repair provide an accessible in vivo human model of inflammation and tissue repair. Progress in our understanding of endometrial pathophysiology has been facilitated by modern cellular and molecular discovery tools, along with animal models of simulated menses. Abnormal uterine bleeding (AUB), including heavy menstrual bleeding (HMB), imposes a massive burden on society, affecting one in four women of reproductive age. Understanding structural and nonstructural causes underpinning AUB is essential to optimize and provide precision in patient management. This is facilitated by careful classification of causes of bleeding. We highlight the crucial need for understanding mechanisms underpinning menstruation and its aberrations. The endometrium is a prime target tissue for selective progesterone receptor modulators (SPRMs). This class of compounds has therapeutic potential for the clinical unmet need of HMB. SPRMs reduce menstrual bleeding by mechanisms still largely unknown. Human menstruation remains a taboo topic, and many questions concerning endometrial physiology that pertain to menstrual bleeding are yet to be answered.

Menstrual irregularity as a biological limit to early pregnancy awareness.

US state legislatures have proposed laws to prohibit abortion once the earliest embryonic electrical activity is detectable (fetal "heartbeat"). On average, this occurs roughly 6 wk after the last menstrual period. To be eligible for abortion, people must recognize pregnancy very early in gestation. The earliest symptom of pregnancy is a missed period, and irregular menstrual cycles-which occur frequently-can delay pregnancy detection past the point of fetal cardiac activity. In our analysis of 1.6 million prospectively recorded menstrual cycles, cycle irregularity was more common among young women, Hispanic women, and women with common health conditions, such as diabetes and polycystic ovary syndrome. These groups face physiological limitations in detecting pregnancy before fetal cardiac activity. Restriction of abortion this early in gestation differentially affects specific population subgroups, for reasons outside of individual control.

Cyclical endometrial repair and regeneration.

Uniquely among adult tissues, the human endometrium undergoes cyclical shedding, scar-free repair and regeneration during a woman's reproductive life. Therefore, it presents an outstanding model for study of such processes. This Review examines what is known of endometrial repair and regeneration following menstruation and parturition, including comparisons with wound repair and the influence of menstrual fluid components. We also discuss the contribution of endometrial stem/progenitor cells to endometrial regeneration, including the importance of the stem cell niche and stem cell-derived extracellular vesicles. Finally, we comment on the value of endometrial epithelial organoids to extend our understanding of endometrial development and regeneration, as well as therapeutic applications.

Association of heavy menstrual bleeding with cardiovascular disease in US female hospitalizations.

BACKGROUND: Heavy menstrual bleeding (HMB) is a common menstrual disorder associated with multiple risk factors of cardiovascular disease (CVD) in women. In addition, HMB is often present with irregular menstruation (IM) which is a risk factor for CVD outcomes. However, the relationship between HMB and CVD outcomes is unexplored in the presence or absence of IM. We determined the association of HMB with multiple CVD outcomes using a nationally representative sample of female hospitalizations in the US. METHODS: All hospitalizations of females with HMB diagnosis and normal menstrual cycles from ages of 18 to 70 years were extracted from the National Inpatient Sample Database, 2017. The HMB was defined using the International Classification of Diseases (ICD)-10 for excessive and frequent menstruation bleeding and included any current or history of HMB diagnosis. Outcomes including major adverse cardiovascular events (MACE), coronary heart disease (CHD), stroke, heart failure (HF), atrial fibrillation (AF) or arrhythmia, myocardial infarction (MI), and diabetes (DM) were defined using ICD-10 codes. Adjusted logistic regression and prosperity scores-matched logistic regression analyses were conducted to summarize adjusted associations with an odds ratio (OR) and a 95% confidence interval (CI). RESULTS: Among 2,430,851 hospitalizations, HMB was observed in 7762 (0.68%) females with age ≤ 40 years and 11,164 (0.86%) females with age > 40 years. Among hospitalizations with age ≤ 40 years, HMB was significantly associated with increased odds of CVD outcomes including MACE (OR = 1.61; 95% CI: 1.25, 2.08), CHD (OR = 1.72; 95% CI: 1.10, 2.71), stroke (OR = 1.95; 95% CI: 1.12, 3.40), HF (OR = 1.53; 95% CI: 1.15, 2.03), and AF/arrhythmia (OR = 1.84; 95% CI: 1.34, 2.54). These associations were confirmed in multiple sensitivity analyses. In contrast, HMB was not robustly associated with CVD events among hospitalizations of women with age > 40 years. HMB without IM was strongly associated with DM, HF, AF, and MACE outcomes while HMB with IM was strongly associated with CHD and AF outcomes in hospitalizations of young women. CONCLUSIONS: HMB is associated with CVD events among US hospitalizations of young women. A routine investigation and screening of menstrual disorders, especially HMB, is useful for CVD risk stratification and management in young women.

A treatment algorithm for familial Mediterranean fever patients with menstruation-associated attacks.

OBJECTIVES: Familial Mediterranean fever (FMF) is characterized by febrile polyserositis attacks. Menstruation could be a trigger for attacks. We aimed to analyze the features of adolescent FMF patients with menstruation-associated attacks and propose a management algorithm. METHODS: All female FMF patients who had menarche and visited the Pediatric Rheumatology Unit between January-December 2022, were included into this study. Demographics, general characteristics, and the features of menstrual cycle and FMF attacks were noted. RESULTS: A total of 151 female FMF patients were included. Thirty-five (23.2%) had menstruation-associated attacks. Fever and arthritis were less frequent during the menstruation-associated attacks than the attacks not associated with menstruation in these patients (65.7% vs 88.6%, p= 0.01 and 2.9% vs 20%, p= 0.04; respectively). Patients with menstruation-associated FMF attacks were younger at symptom onset and diagnosis (2.5 vs 5 years, p= 0.004 and 4 vs 7 years, p= 0.01; respectively), had a higher rate of dysmenorrhea (74.3% vs 38.8%, p< 0.001, respectively) and higher pre- and post-menarche attack frequency (4 vs 2 and 10 vs 0, respectively; p< 0.001 for both) than patients whose attacks were not associated with menstruation. The interventions for menstruation-associated attacks included initiating colchicine, increasing the dose of colchicine, switching from coated to compressed colchicine tablets or anti-interleukin 1 drugs, and on-demand non-steroidal anti-inflammatory drugs, on-demand glucocorticoids, and on-demand anakinra. On-demand therapies were beneficial in controlling menstruation-associated attacks. CONCLUSIONS: This is the largest cohort of adolescent FMF patients with menstruation-associated attacks. Severe FMF may cause tendency to this association. On-demand therapies could be preferred in the management.

Proposal for targeted, neo-evolutionary-oriented, secondary prevention of early-onset endometriosis and adenomyosis. Part I: pathogenic aspects.

The potential for repeated ovulation and menstruation is thought to have provided a Darwinian advantage during the Palaeolithic. Reproductive conditions remained relatively stable until the pre-industrial era, characterized by late menarche, very young age at first birth, multiple pregnancies, and prolonged periods of lactational amenorrhoea. For hundreds of thousands of years, menstruators experienced few ovulatory cycles, even though they were genetically adapted to ovulate and menstruate every month. In the post-industrial era, the age at menarche gradually declined, the age at first birth progressively increased, and breastfeeding became optional and often of short duration. This created a mismatch between genetic adaptation and socio-environmental evolution, so that what was initially a probable reproductive advantage subsequently contributed to increased susceptibility to diseases associated with lifetime oestrogen exposure, such as ovarian, endometrial and breast cancer and, hypothetically, also those associated with the number of ovulatory menstruations, such as endometriosis and adenomyosis. The incidence of endometriosis shows a steep and progressive increase around the age of 25 years, but given the consistently reported delay in diagnosis, the actual incidence curve should be shifted to the left, supporting the possibility that the disease has its roots in adolescence. This raises the question of whether, from an evolutionary point of view, anovulation and amenorrhoea should not still be considered the physiological state, especially in the postmenarchal period. However, an increase in the frequency of endometriosis in recent decades has not been demonstrated, although this deserves further epidemiological investigation. In addition, as endometriosis occurs in a minority of individuals exposed to retrograde menstruation, other important pathogenic factors should be scrutinised. Research should be resumed to explore in more detail the transtubal reflux of not only blood, but also endometrial cells, and whether they are systematically present in the peritoneal fluid after menstruation. If repetitive ovulatory menstruation during the early reproductive years is shown to increase the risk of endometriosis and adenomyosis development and progression in susceptible individuals, hormonal interventions could be used as secondary prevention in symptomatic adolescents.

Proposal for targeted, neo-evolutionary-oriented secondary prevention of early-onset endometriosis and adenomyosis. Part II: medical interventions.

According to consistent epidemiological data, the slope of the incidence curve of endometriosis rises rapidly and sharply around the age of 25 years. The delay in diagnosis is generally reported to be between 5 and 8 years in adult women, but it appears to be over 10 years in adolescents. If this is true, the actual onset of endometriosis in many young women would be chronologically placed in the early postmenarchal years. Ovulation and menstruation are inflammatory events that, when occurring repeatedly for years, may theoretically favour the early development of endometriosis and adenomyosis. Moreover, repeated acute dysmenorrhoea episodes after menarche may not only be an indicator of ensuing endometriosis or adenomyosis, but may also promote the transition from acute to chronic pelvic pain through central sensitization mechanisms, as well as the onset of chronic overlapping pain conditions. Therefore, secondary prevention aimed at reducing suffering, limiting lesion progression, and preserving future reproductive potential should be focused on the age group that could benefit most from the intervention, i.e. severely symptomatic adolescents. Early-onset endometriosis and adenomyosis should be promptly suspected even when physical and ultrasound findings are negative, and long-term ovulatory suppression may be established until conception seeking. As nowadays this could mean using hormonal therapies for several years, drug safety evaluation is crucial. In adolescents without recognized major contraindications to oestrogens, the use of very low-dose combined oral contraceptives is associated with a marginal increase in the individual absolute risk of thromboembolic events. Oral contraceptives containing oestradiol instead of ethinyl oestradiol may further limit such risk. Oral, subcutaneous, and intramuscular progestogens do not increase the thromboembolic risk, but may interfere with attainment of peak bone mass in young women. Levonorgestrel-releasing intra-uterine devices may be a safe alternative for adolescents, as amenorrhoea is frequently induced without suppression of the ovarian activity. With regard to oncological risk, the net effect of long-term oestrogen-progestogen combinations use is a small reduction in overall cancer risk. Whether surgery should be considered the first-line approach in young women with chronic pelvic pain symptoms seems questionable. Especially when large endometriomas or infiltrating lesions are not detected at pelvic imaging, laparoscopy should be reserved to adolescents who refuse hormonal treatments or in whom first-line medications are not effective, not tolerated, or contraindicated. Diagnostic and therapeutic algorithms, including self-reported outcome measures, for young individuals with a clinical suspicion of early-onset endometriosis or adenomyosis are proposed.

Müllerian anomalies and endometriosis as potential explanatory models for the retrograde menstruation/implantation and the embryonic remnants/celomic metaplasia pathogenic theories: a systematic review and meta-analysis.

STUDY QUESTION: Does endometriosis prevalence differ in patients with obstructive Müllerian anomalies (OMA) versus those with nonobstructive Müllerian anomalies (NOMA), and in patients with NOMA versus those without Müllerian anomalies? SUMMARY ANSWER: The quantitative synthesis of published data demonstrates a substantially increased prevalence of endometriosis in patients with OMA compared with those with NOMA, and a similar prevalence in patients with NOMA and those without Müllerian anomalies. WHAT IS KNOWN ALREADY: The pathogenesis of endometriosis has not been definitively clarified yet. A higher prevalence of endometriosis in patients with OMA than in those with NOMA would support the retrograde menstruation (RM)/implantation theory, whereas a higher prevalence of endometriosis in the NOMA group than in the group without Müllerian anomalies would support the embryonic remnants/celomic metaplasia hypothesis. STUDY DESIGN, SIZE, DURATION: This systematic review with meta-analysis was restricted to full-length, English-language articles published in peer-reviewed journals between 1980 and 2023. The PubMed and EMBASE databases were searched using the keyword 'endometriosis' in combination with 'Müllerian anomalies', 'obstructive Müllerian anomalies', 'female genital malformations', 'retrograde menstruation', 'infertility', 'pelvic pain', and 'classification'. References from relevant publications were screened, and PubMed's 'similar articles' and 'cited by' functions were used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Studies were selected if they reported the prevalence of surgically confirmed endometriosis in either individuals with OMA compared to those with NOMA, or patients with NOMA compared to those without Müllerian anomalies. Cohort and case-control studies and case series were deemed eligible for inclusion. Noncomparative studies, studies not reporting both the number of individuals with endometriosis and the total number of those with Müllerian anomalies or with other gynecological conditions, those including exclusively data on patients with absent or uncertain menstrual function (e.g. complete Müllerian agenesis category), or with imperforate hymen were excluded. Two reviewers independently abstracted data. The risk of bias was assessed with the Risk of Bias In Non-randomized Studies of Exposures tool. The overall certainty of the evidence was graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. MAIN RESULTS AND THE ROLE OF CHANCE: Seven retrospective studies were included. The overall mean estimate of endometriosis prevalence was 47% (95% CI, 36-58%) in patients with OMA, and 19% (95% CI, 15-24%) in patients with NOMA, with a common odds ratio (OR) of 4.72 (95% CI, 2.54-8.77). The overall mean estimate of endometriosis prevalence in patients with NOMA was 23% (95% CI, 20-27%), and that in patients without Müllerian anomalies was 21% (95% CI, 20-22%), with a common OR of 0.95 (95% CI, 0.57-1.58). The overall certainty of the evidence according to GRADE guidelines was judged as low for both comparisons. LIMITATIONS, REASON FOR CAUTION: Some NOMA subtypes may create a partial obstacle to menstrual efflux and/or generate dysfunctional myometrial contractions that favor transtubal reflux, thus increasing the risk of endometriosis and limiting the difference between OMA and NOMA. As infertility and pelvic pain are strongly associated with endometriosis, women with these symptoms are inappropriate controls. Confounding by indication could explain the lack of difference in endometriosis prevalence between patients with NOMA and those without Müllerian anomalies. WIDER IMPLICATIONS OF THE FINDINGS: The results of this meta-analysis support the validity of the RM theory but do not definitively rule out alternative hypotheses. Thus, RM may be considered the initiator for the development of endometriotic lesions, while not excluding the contribution of both inheritable and tissue-specific genetic and epigenetic modifications as disease-promoting factors. STUDY FUNDING/COMPETING INTEREST(S): No funding was received for this review. P.Ve. is a member of the Editorial Board of Human Reproduction Open, the Journal of Obstetrics and Gynaecology Canada, and the International Editorial Board of Acta Obstetricia et Gynecologica Scandinavica; has received royalties from Wolters Kluwer for chapters on endometriosis management in the clinical decision support resource UpToDate; and maintains both a public and private gynecological practice. E.S. discloses payments from Ferring for research grants and honoraria from Merck-Serono for lectures. All other authors declare they have no conflict of interest. REGISTRATION NUMBER: N/A.

COVID-19 and abnormal uterine bleeding: potential associations and mechanisms.

The impact of COVID-19 on menstruation has received a high level of public and media interest. Despite this, uncertainty exists about the advice that women and people who menstruate should receive in relation to the expected impact of SARS-CoV-2 infection, long COVID or COVID-19 vaccination on menstruation. Furthermore, the mechanisms leading to these reported menstrual changes are poorly understood. This review evaluates the published literature on COVID-19 and its impact on menstrual bleeding, discussing the strengths and limitations of these studies. We present evidence consistent with SARS-CoV-2 infection and long COVID having an association with changes in menstrual bleeding parameters and that the impact of COVID vaccination on menstruation appears less significant. An overview of menstrual physiology and known causes of abnormal uterine bleeding (AUB) is provided before discussing potential mechanisms which may underpin the menstrual disturbance reported with COVID-19, highlighting areas for future scientific study. Finally, consideration is given to the effect that menstruation may have on COVID-19, including the impact of the ovarian sex hormones on acute COVID-19 severity and susceptibility and reported variation in long COVID symptoms across the menstrual cycle. Understanding the current evidence and addressing gaps in our knowledge in this area are essential to inform public health policy, direct the treatment of menstrual disturbance and facilitate development of new therapies, which may reduce the severity of COVID-19 and improve quality of life for those experiencing long COVID.

Driving improvement of diagnosis and awareness of heavy menstrual bleeding in women among physicians.

INTRODUCTION: A number of barriers in care exist for women/girls with bleeding disorders. Little progress has been made to overcome them, particularly regarding levels of awareness of healthcare professionals (HCPs) and women/girls. AIM: To evaluate awareness and perception of heavy menstrual bleeding (HMB) and bleeding disorders among HCPs and women/girls. METHODS: A three-part qualitative study was conducted, including HCPs and women/girls from over seven countries. Part 1 included eleven 60-min interviews with experts discussing HMB diagnostic barriers, which were further assessed in surveys among 6099 women/girls, 353 general practitioners (GPs), and 426 obstetricians and gynaecologists (OB/GYNs) during Part 2. Part 3 included three 1.5-2-h workshops with 20 clinicians and patient representatives covering HMB knowledge, criteria defining HMB and HCP resourcing for diagnosis. RESULTS: Many HCPs do not conduct certain investigations for women/girls presenting with HMB, and 22% of GPs lack confidence in the management of HMB. Only 8% of GPs use screening tools to evaluate menstrual blood loss, and 13% of GPs and 15% of OB/GYNs assess underlying bleeding disorders. Seventy-six percent of menstruating women/girls believed they could recognise HMB symptoms 'well'. However, 23% of these women/girls would not seek medical advice for abnormal/prolonged menstruation disrupting their lives. Disruptions were reported in 34% of women/girls from the general population and 61% of women with at-risk symptoms of HMB. CONCLUSION: Many women/girls and HCPs have limited awareness of important HMB indicators. There is a need for standardized clinical criteria to promote efficient diagnoses and management.

Is endometriosis due to evolutionary maladaptation?

Similar to diabetes and unlike many pathogen-induced diseases, endometriosis is likely a result of maladaptation to the evolutionary heritage of humans. The objective of this article is to review the literature and improve understanding of the evolutionary factors behind endometriosis, leading to more effective prevention and treatment approaches. In primates, spontaneous decidualization of the endometrium evolved to ensure optimal implantation of a limited number of early embryos, unlike many non-primates which depend on early embryos to induce decidualization and subsequent pregnancy. Spontaneous decidualization results in menstrual bleeding when embryo implantation does not occur, and endometriosis is commonly believed to be caused by retrograde menstruation. Although direct evidence is lacking, it is likely that hunter-gatherer women experienced fewer menstrual periods due to pregnancy shortly after menarche, followed by repeated pregnancies and lactation. However, the mismatch between the evolved uterine physiology and rapid societal changes has led to modern women delaying pregnancy and experiencing numerous menstrual periods, potentially increasing the incidence of endometriosis. The symptoms of endometriosis are often managed by suppressing menstruation through systemic hormonal treatments, but these may have side effects. For patients with a family history of endometriosis or in the early stages of the disease, intrauterine devices releasing progesterone locally could prevent uterine bleeding and the development of endometriosis while preserving fertility and minimizing side effects.

Potential anatomical determinants of retrograde menstruation: a comprehensive narrative review.

A century ago, Sampson identified three uterine anatomical structures that may determine the amount of retrograde menstruation and the likelihood of the development of endometriosis: the cervix, the intramural portion of the fallopian tubes, and the myometrium. Critical appraisal was undertaken of data published over the last 40 years on the potential effect of the characteristics of these three anatomical variables on the risk of endometriosis. There is some evidence to support the pathogenic role of the diameter of the cervical canal, stenosis of internal or external orifices, and stiffness of cervical tissue. One study showed a significant association between the morphology of the intramural tubal tract and the frequency of endometriosis. A large body of evidence points to abnormalities of the myometrial structure as the anatomical aberration most consistently associated with endometriosis. These abnormalities have largely been interpreted as signs of early-onset adenomyosis, which may precede endometriosis and even lead to its development by increasing the amount of retrograde menstruation. Future research should aim to verify whether a positive relationship exists between the substantially increased number of ovulatory menses occurring in the decade following menarche, the development of anatomical myometrial abnormalities, changes in the amount of retrograde menstruation over time, and the risk of endometriosis.

A multidimensional appraisal of early menstrual pain experience.

BACKGROUND: Symptomatic dysmenorrhea is a global problem, affecting more than 40% of menstruating persons. Cross-sectional studies have implicated psychosocial, biological, and sensory factors in dysmenorrhea but the mechanisms are not fully understood. Only a few prospective longitudinal studies have evaluated such factors in relation to the emergence and course of dysmenorrhea at menarche. OBJECTIVE: This study aimed to describe the initial menstruation experience and to evaluate the association of premenarchal psychosocial and sensory factors with the intensity of dysmenorrhea during the period in the fourth month. STUDY DESIGN: This was a prospective cohort study of adolescents who completed premenarchal assessments and postmenarchal daily menstrual diaries for their first (n=149) and fourth month periods (n=114). They were recruited shortly before menarche and completed baseline assessments, including psychosocial questionnaires and experimental pain sensitivity (pressure testing, bladder provocation), and their parents completed related pain questionnaires. The relation between the hypothesized premenarchal factors and month 4 dysmenorrhea intensity was evaluated using Kruskal-Wallis and chi-square tests for low (<3 on a 0-10 scale) vs higher (≥3) menstrual pain groups based on maximal pain ratings recorded in a daily diary. RESULTS: Low levels of dysmenorrhea characterized the first (median, 1; interquartile range, 0-2) and fourth month periods (1; 0-3). Maximal pain ratings increased from the first to the fourth period (3; 1-5 vs 4; 1-6; P=.007). The distribution of dysmenorrhea was multimodal at month 4 with 31.6% of the participants having low levels of maximal pain (1; 0-1) and 68.4% having higher levels (5; 4-6; Hartigan's dip test P<.001). The baseline demographic, psychosocial, and parental pain characteristics were not associated with the development of worse dysmenorrhea. The baseline experimental pain sensitivity, based on pressure pain thresholds, did not differ between the low (15.7 N; 12.5-22.3) and higher (15.0 N; 10.9-21.4]) level dysmenorrhea groups. Baseline bladder pain at first urge also did not differ (low, 6; 0-20 vs higher, 7; 0-19). CONCLUSION: By their fourth month period, two-thirds of adolescents fell into the higher group for maximal dysmenorrhea, half reported some related impairments in physical activity, and one-seventh reported some related school absence. Premenarchal factors (experimental pain sensitivity, psychosocial profile, parental pain experience) linked to chronic pain emergence in the adult literature did not predict dysmenorrhea intensity, suggesting the dominant factor at menarche may be peripheral afferent activation. Further research is needed to understand the evolution of psychosocial and sensory mechanisms in the development and course of dysmenorrhea.

Impact of symptoms, experiences, and perceptions of the menstrual cycle on recreational physical activity of cyclically menstruating individuals: A systematic review.

OBJECTIVE: The menstrual cycle often presents barriers to participation in daily life activities, including physical activity (PA), which is a cornerstone of health and well-being. The purpose of this systematic review was to explore and summarize the impact of symptoms, experiences, and perceptions of the menstrual cycle on recreational PA (RPA), including sports, exercise and active recreation, in the general population. METHODS: Six databases were searched for studies that investigated the impact of the menstrual cycle on PA among individuals who were cyclically menstruating, healthy, and not involved in professional sports training. RESULTS: The search yielded 3025 studies that were screened for relevance and eligibility, resulting in 25 eligible studies, which were found to be of moderate-to-high quality following a quality and risk-of-bias assessment. Thematic synthesis of qualitative and quantitative data from the selected studies, constituting 16,557 adults and 3715 adolescents, identified the impact of menstrual symptoms on the physical and psychological capability to participate in RPA, social opportunity barriers to RPA (e.g., social pressure due to the sociocultural taboo against menstruation), as well reflective (knowledge) and automatic (habit) motivation on RPA behaviours. CONCLUSION: The variability in menstrual symptoms and corresponding experiences suggested the need for an individualized approach to RPA promotion. Furthermore, this review highlighted the need to address the sociocultural taboo against menstruation, as well as improve the provision of knowledge and resources related to the menstrual cycle and RPA, in order to promote and facilitate RPA for cyclically menstruating individuals throughout the menstrual cycle.

Preliminary investigation into long-term stress by isolated captivity-related changes of reproduction hormones in Cynomolgus monkey.

BACKGROUND: Stress profoundly affects physical and emotional well-being, extending its physiological influence to the female menstrual cycle, impeding the hypothalamus-pituitary-gonadal (HPG) axis, and affecting fertility by suppressing sex-stimulating hormones. METHODS: In this study, we meticulously analyzed menstrual cycles and corresponding hormonal fluctuations in three female Cynomolgus monkeys. RESULTS: The preliminary findings indicated lower-than-normal levels of cortisol, follicle-stimulating hormone (FSH), and estradiol. Anovulatory bleeding occurred in one monkey, which could be linked to stress. In contrast to cortisol, alkaline phosphatase (ALP), which is correlated to cortisol levels, was consistently elevated in menstruating monkeys, suggesting its potential as a stress indicator. The non-menstruating group exhibited stress-related weight loss, emphasizing the observed ALP trends. CONCLUSIONS: Non-menstruating monkeys may experience more stress than menstruating monkeys. The implications of this study extend beyond the confines of primate studies and offer a valuable method for enhancing the welfare of female Cynomolgus monkeys.

Preferences and experiences of parents/guardians of youth with epilepsy and intellectual disability on reproductive health counseling.

OBJECTIVE: To explore the experiences and preferences of parents/guardians of adolescents and young adults (AYA) of childbearing potential with co-occurring epilepsy and intellectual disability (ID) regarding counseling by neurologists on sexual and reproductive health (SRH) topics such as pregnancy, contraception, menstruation, and folic acid supplementation. METHODS: We conducted semi-structured interviews with parents/guardians of AYAs (12-28 years old) of childbearing potential with co-occurring epilepsy and ID, recruited from a tertiary-care children's hospital. We confirmed the diagnoses of epilepsy and ID with the patient's neurologist and parent/guardian. All degrees of ID (e.g. mild/moderate/severe) were eligible. We audio-recorded and transcribed interviews. Two coders performed qualitative thematic analysis. RESULTS: Twenty-five parents/guardians completed interviews. Themes included: (1) Parents/guardians believe their child to be immune from sexual abuse due to their supervision, yet desire counseling about abuse recognition and prevention, which they also report not occurring (2) A common opinion was that counseling on menstruation was more relevant to their child's life than counseling about pregnancy-related topics (3) Parents/guardians reported a lack of counseling on pregnancy-related topics such as folic acid supplementation and teratogenesis and generally also reported some degree of interest in hearing about these topics from neurologists (4) Parents/guardians also reported a lack of counseling on drug interactions between contraception and ASMs, and were highly interested in learning more about this topic (5) Parents/guardians want neurologists to initiate annual comprehensive SRH counseling at puberty about most topics, but report that they often initiate SRH discussions themselves. CONCLUSION: Parents/guardians of AYAs with epilepsy and ID prefer more frequent, neurologist-initiated, comprehensive conversations surrounding SRH particularly emphasizing menstruation and sexual abuse recognition/prevention. Findings may inform professional and patient education and health systems interventions including development of discussion guides and/or decision aides to improve SRH care for AYAs with epilepsy and ID.

Adverse Menstrual Events Reported After and Before (or Without) COVID-19 Vaccination: A Systematic Review and Meta-Analysis of Comparative Observational Studies.

BACKGROUND: Reports of adverse menstrual events emerged during the COVID-19 vaccination campaign in multiple countries. This raised the question whether these reports were caused by the vaccines. The aim of this systematic review was to evaluate comparative studies on this topic (registered at PROSPERO [CRD42022324973]). METHODS: We included observational studies such as cohort studies and surveys comparing the response to self-reported questionnaires between post- versus pre-vaccination data. PubMed and Cochrane Library searches were conducted on 1 September 2023. The primary outcome was the incidence of any prespecified adverse menstrual event, and the outcome measure was the risk ratio. The meta-analysis was conducted by using the Mantel-Haenszel method and the random effects model. We summarized the results on risk factors as well as key findings of the studies included. RESULTS: We retrieved 161 references from electronic databases and additional sources such as references lists. Of those, we considered 21 comparative observational studies. The meta-analysis of any adverse menstrual adverse event reported in 12 studies resulted in a pooled estimate (risk ratio 1.13; 95% CI, 0.96-1.31) that did not favor any group. The analysis was constrained by considerable clinical and statistical heterogeneity. Risk factors for self-reported menstrual changes included a history of COVID-19 infection, the concern about COVID-19 vaccines, smoking, previous cycle irregularities, depression, and stress, and other issues. CONCLUSIONS: The risk ratio did not favor any group and heterogeneity was prevalent among the studies. Most studies suggested that the reported changes were temporary, minor, and nonserious.

Menstrual blood loss is an independent determinant of hemoglobin and ferritin levels in premenopausal blood donors.

INTRODUCTION: To prevent blood donors from developing iron deficiency (ferritin <15 µg/L) and subsequent anemia (hemoglobin <120 g/L), blood services rely on information about known risk factors, including the donor's sex and age. For example, while Finnish women are able to donate whole blood with a minimum donation interval of 91 days, women in the 18 to 25-year-old age group are recommended to donate no more than once per year. Menstrual blood loss is not accounted for in blood donation interval recommendations, despite being a known risk factor of iron deficiency. We aim to investigate to what extent menstrual bleeding is associated with ferritin and hemoglobin levels in female blood donors, and quantify the association of other menstruation-related variables not currently accounted for by blood services (i.e., use of hormonal contraception, heavy menstrual bleeding) with iron deficiency or anemia. MATERIAL AND METHODS: The study population consisted of 473 premenopausal and 491 postmenopausal Dutch whole blood donors. Exclusion criteria were current pregnancy, BMI ≥50, ferritin ≥200, pictorial blood assessment chart (PBAC) ≥400, and age <18 or ≥70 years. Menstrual blood loss was quantified using a PBAC, a semiquantitative method to evaluate the number of used menstrual products and the degree of staining. We identified predictors of log(ferritin)/hemoglobin and iron deficiency/anemia using Bayesian linear and logistic regression models and quantified the average percentage of variance in log(ferritin) and hemoglobin explained by the covariates. RESULTS: Menstrual blood loss accounted for most of the explained variance in hemoglobin (8%) and second only to the number of days since last donation for ferritin (8%). Heavy menstrual bleeding (PBAC ≥150, OR = 3.56 [1.45-8.85], prevalence 13%) was associated with anemia, and use of levonorgestrel-releasing intrauterine device was negatively associated with iron deficiency (OR = 0.06 [0.01-0.44]). After statistical control for menstrual blood loss, age was not associated with iron status. CONCLUSIONS: Menstrual blood loss and blood donation were the most important determinants of iron status in premenopausal women. Thus, results suggest that accounting for menstrual blood loss in donation interval guidelines may benefit blood donors.

Menstrual hygiene management practice and associated factors among high school and preparatory school adolescent students in Debre Markos town, Northwest, Ethiopia: a mixed-method study.

BACKGROUND: Despite being a normal occurrence, menstruation requires hygienic care and is associated with a number of myths and wrongdoings. Menstrual hygiene issues have been linked to major health issues, such as urinary tract and reproductive tract infections. Consequently, the purpose of this study was to evaluate the management of menstrual hygiene and related aspects among teenage students in Debre Markos town, North West, Ethiopia. METHODS: From March 15 to April 15, 2019, teenage pupils in Debre Markos town participated in a cross-sectional mixed study. An in-depth interview and a self-administered structured questionnaire were used to gather data. Quantitative information was imported into Epi Data and then exported to SPSS for examination. A 95% Confidence Interval of p-value ≤ 0.05 was used to declare significance. The method of thematic content analysis was used to examine the qualitative data. RESULT: This study comprised 531 individuals in total, with a 96.2% response rate. Approximately 260 adolescent females (49%, 95% CI: 39.2, 59.2) had good management practices for menstrual hygiene. Girls whose mothers were private employees (AOR: 0.3, 95% CI: 0.09, 0.99), self-employed (AOR: 0.52, 95% CI: 0.28, 0.98) and housewives (AOR: 0.53, 95% CI: 0.29, 0.98), and parent-adolescent discussions about menstruation (AOR: 1.62, 95% CI: 1.40, 3.34) were significantly associated with good menstrual hygiene management. Adolescence aged 17 years or older (AOR: 2.13, 95% CI: 1.32, 3.44) were found to have good knowledge regarding menstrual hygiene (AOR: 1.59, 95% CI: 1.43, 2.94). The qualitative study found that ignorance, an unfavorable school climate, and cultural and economic factors were the main causes of teenagers' poor menstrual hygiene. CONCLUSION: Nearly half of adolescent girls had good menstrual hygiene practice. Menstrual hygiene practice was associated with adolescent age, knowledge of menstruation, maternal occupational and discussion with parents. Girls had difficulty to manage menstrual hygiene due to poor knowledge, unsafe school environment, and cultural barriers. Thus, school-based programs aimed at improving knowledge towards menstrual hygiene management are needed.