Menstrual Cycle

This prospective observational cohort study aims to evaluate the association between menstrual phase (determined by postoperative serum progesterone levels), intraoperative anesthetic consumption, and the incidence and severity of postoperative nausea and vomiting (PONV) in female patients undergoing cholecystectomy. Intraoperative anesthetic requirements will be recorded, and postoperative nausea and vomiting will be assessed using standardized scoring systems.

The complexity inherent to the hormonal fluctuations associated with the female menstrual cycle (MC) has contributed, from a methodological perspective in research, to the neglect of women's physiological characteristics and to the silencing and normalization of symptoms linked to different life stages and hormonal environments. The scarce and outdated available data suggest high percentages of women experiencing perimenstrual symptoms, such as premenstrual syndrome or menstrual pain, as well as intermenstrual discomfort. These symptoms not only significantly impair daily activities but, due to their normalization, often lead to the underdiagnosis of other gynecological conditions. Subclinical ovulatory disturbances-characterized by the suppression of ovarian hormones as an adaptive defense mechanism against various environmental stressors-are also frequently underdiagnosed. These disturbances typically do not affect MC length, making them difficult to detect, and although the process is reversible, it may initiate irreversible consequences for certain tissues, such as bone mass loss. However, neither women nor their educational, occupational, or healthcare environments appear to have the resources and/or knowledge required to adequately address these issues. All of this may compromise women's rights to adequate sexual and reproductive health and to a dignified quality of life, as recognized under the second line of Axis 4, "Effective Rights for All Women," of the Strategic Plan for Effective Equality between Women and Men 2022-2025. Therefore, the aims of this multicenter project-carried out by a multidisciplinary research team from seven Spanish universities and three international institutions-are to describe the prevalence of symptoms and alterations related to the MC in women of reproductive age and to identify their associations with physical and mental health. To accomplish this, an observational study will be conducted in a large sample of women of reproductive age, including multiple symptom and perceived-health questionnaires and ovulation monitoring. In addition, in a subsample of participants, bone mineral density will be assessed, blood levels of sex hormones will be monitored, and an innovative analysis of health biomarkers (glycemic and lipid profile, and inflammation) from menstrual blood will be included. This will be complemented by a qualitative study of experiences related to MC-associated symptoms and alterations, using in-depth interviews and thematic content analysis. The findings of this project are expected to support various dissemination and educational actions, justify the design of more inclusive educational and healthcare policies, and enhance the understanding of women's needs, ultimately contributing to improved symptom management and quality of life.

In infertility treatment, embryos are created in vitro after eggs have been fertilised by sperm using in vitro fertilisation or intracytoplasmic sperm injection techniques. These embryos, resulting from hormonal ovarian stimulation, can be transferred shortly after egg retrieval (fresh transfer) or frozen for later use. Both natural menstrual cycles and artificial cycles (using hormones to mimic a normal cycle) can prepare the uterus for embryo transfer. Patients with regular menstrual cycles often prefer the non-medicated approach. However, these cycles offer less flexibility in timing because they rely on ovulation. As the number of FET cycles increases worldwide, scientists are exploring the possibility of inducing ovulation in smaller follicles to increase the flexibility of natural cycles. However, the safety for future pregnancies is unknown. This study aims to better understand the function of the corpus luteum, the follicle remnant in the ovary after ovulation, by measuring several factors that change throughout the cycle due to substances produced by the corpus luteum. The results of the study will have a direct impact on clinical practice by increasing the flexibility of frozen transfer cycles.

This study is investigating how two types of non-invasive brain stimulation, transcranial electrical stimulation (TES) and transcranial magnetic stimulation (TMS), affect brain activity, and whether combining them produces stronger or more consistent effects than either one used alone. The motivation for this comes from the observation that TMS, which is FDA-approved for treating depression, tends to work less well in postmenopausal women because lower estrogen levels reduce the brain's ability to respond to stimulation. The research team believes that pairing TMS with TES, which targets a different set of brain cells, may be able to overcome this hormonal barrier and make stimulation more effective. Participants will come into the lab for up to 24 visits over 8 months, beginning with an initial visit to establish the right stimulation settings, followed by a series of stimulation sessions in which brain activity is measured before and after receiving either TES, TMS, or both together. For female participants, sessions will be scheduled at specific points in the menstrual cycle to capture the natural monthly rise and fall of estrogen, while male participants will be scheduled on a comparable fixed interval as a comparison group. The insights gained from this study could directly inform the development of better, more reliable brain stimulation treatments for women with depression.

The goal of this clinical trial is to learn if a postbiotic supplement can reduce stomach and gut symptoms in physically active women. The main questions it aims to answer are: Does the supplement reduce gut symptoms during the menstrual cycle? Does it improve symptoms related to exercise? Researchers will compare the postbiotic supplement to a placebo (a look-alike capsule that contains no active ingredient) to see if the supplement works. Participants will be physically active, premenopausal female athletes. Participants will: Take either the postbiotic supplement or a placebo each day for two menstrual cycles Track their menstrual cycle and training Report gut symptoms using regular questionnaires Provide stool samples to assess gut health This study will help researchers understand whether postbiotic supplements can improve gut health and reduce symptoms that may affect training and performance in female athletes.

A review of the sports medicine literature reveals a clear underrepresentation of female athletes in research. In the current era of precision medicine, increasing attention has been directed toward the regulatory roles of estrogen and progesterone in athletic performance and health optimization. Regular fluctuations in estrogen and progesterone across menstrual cycle phases (i.e., early follicular, late follicular, and mid-luteal phases) may influence strength performance, hydration status, body composition, and energy balance. However, few studies have examined these outcomes using hormonal confirmation of menstrual cycle phases. Monophasic oral contraceptive use also represents a highly relevant hormonal condition among female athletes, as exogenous hormones suppress endogenous ovarian fluctuations and create distinct hormonal profiles across active pill-consumption and withdrawal phases. Nevertheless, the influence of oral contraceptive phases on strength-related outcomes, hydration markers, body water regulation, body composition, and energy balance remains insufficiently characterized, particularly in comparison with naturally menstruating athletes. In response to these gaps, this longitudinal observational study primarily aims to examine variations in strength-related outcomes across three distinct menstrual cycle phases (early follicular, late follicular, and mid-luteal) in eumenorrheic athletes. Secondary objectives include: (i) conducting within- and between-group comparisons of hydration status, energy balance, and strength outcomes (maximal, endurance, and explosive torque) in naturally menstruating athletes and oral contraceptive users; (ii) testing the reliability of methods used to assess body water, energy expenditure, and body composition across the menstrual cycle; (iii) exploring associations between energy availability, resting energy expenditure, and sex hormone concentrations across menstrual cycle phases; and (iv) testing, validating, and proposing methodological recommendations for the use of bioelectrical impedance analysis in tracking fluid-related changes across hormonal phases. To achieve these goals, the study will use a longitudinal observational design involving 40 female athletes, including 24 naturally menstruating athletes and 16 oral contraceptive users. Naturally menstruating athletes will be assessed during the early follicular, late follicular, and mid-luteal phases of the menstrual cycle, while oral contraceptive users will be assessed across pill-consumption and withdrawal phases. Measurements will be conducted across the three menstrual cycle phases and across oral contraceptive use phases, and will include: i) maximal voluntary isometric strength assessed using handgrip dynamometry, bench press, and leg press; ii) serum estrogen and progesterone; iii) body water and its compartments, and water turnover by dilution techniques; iv) hydration status by plasma osmolality, sodium, and vasopressin; v) energy balance by doubly labeled water and body composition changes; vi) resting energy expenditure by indirect calorimetry.

The investigators will obtain urine hormone results and validated menstrual bleeding score from people experiencing abnormal uterine bleeding. The investigators will evaluate satisfaction and ease of use of Mira monitor. The investigators will measure recruitment rate, attrition and cycle collection completeness of data. The investigators will evaluate menstrual health literacy at baseline and at the conclusion of the study.

This research is being done to examine epigenetic markers and mood changes across the menstrual cycle, particularly in premenstrual dysphoric disorder (PMDD). The investigators previously identified epigenetic biomarkers of postpartum depression, another reproductive affective disorder, and in this study aim to determine if these biomarkers also distinguish PMDD cases from healthy controls at different points in the menstrual cycle. By collecting biological samples (such as blood) and monitoring mood changes across the menstrual cycle, the investigators will be able to determine whether these epigenetic markers are associated with PMDD. The investigators plan to study these epigenetic markers during the follicular phase (roughly the first half of the menstrual cycle, from menses until ovulation) and the luteal phase (roughly the second half of the menstrual cycle, from ovulation to menses). The investigators will study this in two groups: 1) individuals who do NOT have premenstrual mood symptoms, and 2) individuals with premenstrual syndrome/premenstrual dysphoric disorder (PMS/PMDD). The results will provide a comprehensive view of the changes in these systems across the menstrual cycle. This will add to the investigators understanding of the mechanisms that may cause PMS/PMDD.

Phenylalanine is an essential amino acid that must be obtained through food. Current adult phenylalanine recommendation is based on male-conducted studies and set the same for females. These recommendations may not be appropriate for females, as they do not take into consideration the hormonal changes over the menstrual cycle. The menstrual cycle is a rhythmic hormonal process split into two phases, with hormones regulating metabolism differently. The aim of this study is to find phenylalanine requirement for healthy, menstruating females. An innovative, non-invasive technique utilizing pre-determined diets, safe stable isotopes, and a simple breath collection method will be used. Previous work done by Elango Lab investigators has applied this method to investigate other amino acids in pregnant, non-pregnant, and lactating females as well as in children.

This prospective observational cohort study aims to evaluate the association between menstrual phase (determined by postoperative serum progesterone levels), intraoperative anesthetic consumption, and the incidence and severity of postoperative nausea and vomiting (PONV) in female patients undergoing cholecystectomy. Intraoperative anesthetic requirements will be recorded, and postoperative nausea and vomiting will be assessed using standardized scoring systems.

This observational study aims to evaluate the effect of menstrual cycle phase on optic nerve sheath diameter (ONSD) in women undergoing elective laparoscopic gynecologic surgery. Patients will be grouped according to menstrual cycle phase as follicular or luteal. ONSD measurements will be performed perioperatively, and postoperative nausea and vomiting as well as postoperative cognitive function will also be assessed. The study is designed to investigate whether hormonal variations during the menstrual cycle are associated with differences in intracranial pressure reflected by ONSD measurements and postoperative outcomes

Females treated with antipsychotics have higher rates of comorbid metabolic syndrome than males. Despite this, females have historically been excluded from many mechanistic studies due to confounding effects of menstrual cycles. Recent evidence suggests that brain insulin resistance may be an underlying mechanism through which antipsychotics may exert their metabolic side effects. This study seeks to investigate how brain insulin action differs in females according to their menstrual cycle phase, and how a high metabolic liability agent such as olanzapine might interrupt these differential insulin effects. Young healthy females will be given olanzapine and intranasal insulin to test how these treatment combinations change brain processes. Participants will be tested during both the first half of their menstrual cycle (follicular phase) and the second half of their cycle (luteal phase). The investigators predict that intranasal insulin will change MRI-based measures in females, in a comparable way to males, in the follicular phase only. Adding olanzapine will block these effects of insulin in females in the follicular phase. This investigation has the potential to generate new knowledge in an area of significant unmet need. Demonstrating that antipsychotics disrupt brain insulin action, evidenced by inhibition of recognized effects of insulin on neuroimaging measures, will provide novel insights into currently poorly understood mechanisms.

This clinical trial aims to evaluate how variations in dietary fat content and hormonal status influence postprandial glycemic response in individuals with type 1 diabetes (T1D), with a special focus on women. The main objective is to clarify the impact of both factors individually and their interaction, which could inform more personalized strategies for insulin adjustment, optimizing glycemic control, and improving patient outcomes. The main objective is to investigate the effects of low-fat versus high-fat meals, sex, menstrual cycle phases, and their interaction on postprandial glycemic control in adults with T1D treated with advanced hybrid closed-loop (AHCL) insulin delivery systems. Specifically, the study will: * Compare postprandial glycemic responses after standardized low and high-fat meals in men and women with T1D. * Assess the differences in postprandial glycemic responses between early follicular and late luteal phases in women, using standardized meals with low and high fat content. * Identify sex-related differences in glycemic response after equivalent meals. This research addresses the unmet clinical need for precise, tailored postprandial insulin dosing recommendations, especially among women whose insulin sensitivity fluctuates with menstrual phases. The results may contribute to sex-specific predictive models in AHCL systems, reducing acute complications and improving overall quality of life. This is a randomized controlled crossover trial in which each participant serves as her/his own control. Fifty adults will be enrolled: 25 women and 25 men. Women will undergo four mixed-meal tests in random order: * low-fat given during the early follicular phase, * high-fat given during the early follicular phase, * low-fat given during the late luteal phase, * high-fat given during the late luteal phase. The menstrual phase will be confirmed with home-based hormonal monitoring devices that function with urine sample and use a single-use test wand (MIRA system). Men will complete two mixed-meal tests (low-fat and high-fat), in randomized order. All meals will be standardized for carbohydrate content and matched in other macronutrients, except for fat (with a 30-40g difference), administered after an 8-hour fast. The day of the mixed meal test, AHCL systems will be switched from automatic to manual mode just before eating to standardize the prandial insulin dose and to avoid differences in insulin infusion rates in the postprandial state due to algorithm compensations. Continuous glucose monitoring (CGM) and hourly capillary glucose testing will measure the postprandial response. Additional fasting blood samples will assess metabolic, hormonal, and lipid markers. Optional gastric emptying studies may be performed to exclude confounding gastroparesis in selected patients. Participants will be recruited from the endocrinology outpatient unit of La Fe Polytechnic University Hospital . The projected recruitment period is from December 2025 to July 2027, with mixed-meal tests and data collection occurring between January 2026 and December 2027. Women are expected to complete the protocol in 6 weeks (4 tests), while men will require about 2 weeks (2 tests). At baseline, participants will undergo blood tests to rule out endocrine disorders and confirm sex hormone status. Women participating in the study will use the MIRA home device to monitor their hormonal levels, allowing them to accurately determine and record the phases of their menstrual cycle as part of the study protocol. During meal tests, CGM (Freestyle Libre 3) will be used uniformly among subjects. The study dependent variables will be the following: * Postprandial glucose area under the curve - AUC\_PG\_5h * Mean glucose level - MG * Continuous glucose monitoring metrics - TIR, TAR, TBR * Postprandial glucose standard deviation - SD * Postprandial glucose coefficient of variation - CV * Mean amplitude of glycemic excursions - MAGE * Mean of daily differences (MODD) Independent variables are * Type of food: Meals with either low or high fat content. * Sex and Hormonal status: men; women during the early follicular phase; women during the late luteal phase. If successful, this study will inform the development of more sophisticated, individualized insulin dosing algorithms and AHCL system improvements, especially for women with T1D. Results may lead to more effective management strategies, reduced GV, lower incidence of complications, and increased quality of life. Insights may directly support the personalization of diabetes care and improve gender equity in treatment standards.

This observational study aims to evaluate the relationship between menstrual cycle phases and the incidence of postoperative nausea and vomiting (PONV) in women of reproductive age undergoing septorhinoplasty surgery. The study's primary objective is to determine whether different phases of the menstrual cycle are associated with variations in PONV frequency. As a secondary objective, the relationship between menstrual phases, PONV incidence, and the use of sugammadex during anesthesia will be analyzed. No additional intervention will be applied beyond routine clinical practice; all data will be collected prospectively from anesthesia records and postoperative evaluations.

This study examines how different phases of the menstrual cycle are associated with selected performance and musculoskeletal parameters in physically active women aged 18-35 years. Participants will track their menstrual cycle using a mobile app for approximately 2 months and attend 3 laboratory visits scheduled to specific cycle phases. At each visit, participants will complete non-invasive assessments including lower-limb strength/performance testing, musculoskeletal measurements (muscle and tendon properties), body composition assessment, and symptom-related questionnaires. The goal is to improve understanding of physiological variability across the menstrual cycle and support evidence-based planning of training, testing, and clinical practice in women.

This study will compare different combinations of fertility signs (cervical mucus (CM), luteinizing hormone \[LH\], pregnanediol glucuronide \[PDG\], and basal body temperature \[BBT\]) to determine which are most reliable for identifying ovulation and luteal phase length. Thirty existing Premom App users will track daily observations for three menstrual cycles. Participants will record mucus, perform urine tests, upload test strip photos to the Premom App, and measure BBT. Both participant readings and AI-assisted app readings will be analyzed. The main goal is to find which marker pairings give the most accurate picture of ovulation timing and luteal phase length. Secondary goals include understanding ease of use, the number of tests required, and whether the app improves accuracy.

The muscles of the body are constantly breaking down old proteins and building new ones. These two processes, protein breakdown and protein synthesis, together are known as protein turnover. Protein turnover is essential for maintaining healthy muscle. Despite its importance, females have historically been underrepresented in protein metabolism research. A long-standing assumption has been that fluctuations in female sex hormones such as estrogen and progesterone, whether across the natural menstrual cycle or in individuals using oral contraceptives (OCs), make metabolism and training responses too variable to study. Because of this, many researchers have excluded female participants for logistical reasons. Resistance exercise, such as weightlifting, is the most effective way to increase muscle size and strength. Each resistance-training session triggers muscle protein synthesis (MPS), the process by which new muscle proteins are built. Consuming dietary protein or individual amino acids further increases the rate at which new proteins are formed. Over time, higher rates of protein synthesis support muscle growth and the maintenance of other lean tissues in the body. The purpose of this study is to examine how menstrual cycle phases and OC use influence the synthesis of proteins in both muscle tissue and the rest of the body. Improving scientific understanding in this area will support more effective, evidence-based training and nutrition recommendations for females.

In this prospective observational study, the effect of timing of insertion (early/late follicular; early/late luteal) on ovarian cyst development in women receiving an LNG-IUD will be assessed ultrasonographically at months 0, 3, 6, and 12. Secondary outcomes include cyst size/structure, bleeding pattern, pain, and other adverse events.

The menstrual cycle implies a basic difference in the biology of women and men but the effect of the hormonal variation on training protocols and physical performance is still not fully understood. Despite no existing evidence, the advice to periodize exercise according to the menstrual cycle has been widely spread among elite athletes, coaches, and sports federations. The advice is based on underpowered studies with considerable methodological weaknesses regarding determination of cycle phase, inclusion of athletes and lack of adequate control groups. The purpose of this randomized, controlled study is to evaluate the effect of exercise periodization on aerobic fitness during different phases of the menstrual cycle. Further, the effect will be related to premenstrual symptoms, body composition and skeletal muscle morphology, sex hormone receptors, metabolic enzymes, and markers of muscle protein synthesis. This study will be well controlled and follow methodology recommendations for menstrual cycle research in sports and exercise. Female athletes of fertile age will be randomized to different training regimens during three menstrual cycles (12 weeks): Group A: Training three times a week throughout the menstrual cycle. Group B: Follicular phase-based training five times a week during the follicular phase and thereafter once a week during the luteal phase. Group C: Luteal phase-based training five times a week during the luteal phase and once a week in the follicular phase. The exercise will consist of high intensity intermittent spinning classes. Assessment of aerobic fitness and power will be performed at baseline, and again after three completed menstrual cycles. On the same day, body composition will be examined by DXA and blood samples will be collected for analysis of hormones and binding proteins. To confirm menstrual cycle phase, blood samples will be collected for hormone determination, and urinary stick will be used for detection of ovulation. Subjective ratings of menstrual cycle related symptoms will be performed every day. In a subgroup of women, muscle biopsies will be collected from m vastus lateralis at baseline and at the end of the study. This study will contribute to improved knowledge about exercise periodization in relation to the menstrual cycle. Well-grounded data is crucial to give evidence-based recommendations to female athletes when planning their training protocol to optimize training results and performance.

There is a knowledge gap about the influence of the menstrual cycle on bladder function in women with spinal cord injury. So far, studies regarding urinary incontinence have primarily focused on women after menopause. It has become clear that a lack of the sex hormone estrogen, which occurs after menopause, can lead to urinary incontinence. During the course of the menstrual cycle, women also experience fluctuations in their sex hormones, particularly estrogen. The estrogen level is highest before ovulation and decreases afterwards. The investigators aim to explore whether this drop in hormone levels could lead to more frequent urinary incontinence during this phase. In order to offer the patients optimal treatment for urinary incontinence, it is important to understand the potential causes behind it. Participants will document their menstrual cycles and episodes of urinary incontinences over three menstrual cycles using a diary, and urine tests. This research project is a pilot study and is being conducted by Swiss Paraplegic Research at the Swiss Paraplegic Centre. The investigators are recruiting 12 participants who experience incontinence at least once a month and 12 participants who experience incontinence less frequently or not at all.

With an increase in number of female athletes in sport events, it is becoming more important to gain insight in female related sports physiology. A main difference between male anf female athletes is the menstrual cycle. During the menstrual cycle, female reproductive hormones fluctuate. These hormones are also of influence on endurance, recovery, muscle strenght and mental state. Therefore we hypothesize that training efficiancy, power and motivation to train differ during the menstrual cycle. In case there is a pattern seen during the menstrual cycle, training programs can be individualized taking the menstrual cycle into account leading to more effective training programs.

The goal of this clinical trial is to evaluate the impact of moderate aerobic exercise on menstrual symptom management in sedentary women both using and not using hormonal contraceptives. The main questions it aims to answer are: Is there a reduction in physical and/or psychological menstrual cycle related symptom burden with participation in moderate aerobic exercise for sedentary women using and not using hormonal contraceptives? Is there a difference in physical and/or psychological menstrual cycle related symptom burden between hormonal contraceptive and non-hormonal contraceptive users? Is a moderate aerobic exercise intervention more effective in reducing physical and/or psychological menstrual related symptom burden for sedentary women using or not using hormonal contraceptives? Participants will: * Have their body composition assessed using dual energy X-ray absorptiometry pre and post exercise intervention. * Complete a Menstrual Symptom Index (MSi) to report daily menstrual cycle related symptom burden in addition to the Premenstrual Symptom Screening Tool (PSST) and Heavy Menstrual Bleeding (HMB) questionnaire monthly. * Utilize an at-home monitor to test urinary luteinizing hormone, estrone-3-glucuronide, and pregnanediol glucuronide approximately 10 times per month and report menstrual cycle length. * Record physical activity habits by continuously wearing a wrist-based accelerometer and chest-strap heart rate monitor during planned aerobic exercise sessions and complete the International Physical Activity Questionnaire (IPAQ) monthly. * Maintain their usual sedentary activity habits for one menstrual cycle followed by completion of an exercise intervention designed to progress individuals to meet minimum recommended aerobic physical activity guidelines of 150 minutes per week set by the American College of Sports Medicine for two menstrual cycles.

The menstrual cycle is a term to describe the sequence of events that occur in body as it prepares for the possibility of pregnancy each month. The average length of a menstrual cycle is 28 days. However a cycle can range in length from 21 days to about 35 days and still normal. The menstrual cycle is the time from the first day of your menstrual period until the first day of your next menstrual period. Every person's cycle is slightly different, but the process is the same. Menstruation is the monthly shedding of the lining of the uterus. Menstrual blood which is partly blood and partly tissue from the inside of the uterus flows from the uterus through the cervix and out of the body through vagina. Some people experience symptoms of menstruation and others don't. The intensity of these symptoms can also vary. The most common symptom is cramps. The cramping you feel in your pelvic area is your uterus contracting to release its lining. Menstrual cycle have four phases, menses phase (3 to 7 days of your periods), follicular phase (during the 10 to 14 days), ovulation phase (14 day if cycle is 28 days) and luteal phase (15 to 28 days).These will a Randomized control trial conduct on 42 participants. The data will be collected ffrom ladies gym and muscle work gym by using non-probability convenience sampling technique. The age between 18-25 years participants will perform the aerobic exercises during the different phases of menstrual cycle. A sample will be divided into two groups each group have 21 participants. The Group A control group will Education and Self-Management about health and fitness and perform the walk. Group B intervention group will be given the Aerobic exercise (cycling, treadmill and running). The participants assessed with Borg scale for rate perceived exertion, berg balance questionnaire use for performance test parameters and menstrual stress questionnaire use for behaviour. Data will be analyzed by using SPSS version 26.0.

Fascial plane blocks are traditionally considered regional anesthesia techniques, where a mixture of local anesthetic (LA) is injected into a plane between two fascial layers, with the aim of spreading along this anatomical plane to block the nerves lying within or passing through it . Various pathophysiological processes that alter the structure and characteristics of fasciae can affect the spread of the local anesthetic and the success of the block. Diabetes, hormonal changes, and cannabinoid use are among these factors. This study aims to investigate the effects of hormonal changes during the menstrual cycle on subcostal TAP block.

The study aims to investigate the effects of sleep deprivation on women's health across different phases of the menstrual cycle.