NCT07037082

Understanding Cycles to Improve Women's Health

Understanding Socio-ecological Variation in Menstrual Cycles to Advance Female Health

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 320 (estimated)
• Sponsor: University Hospital, Montpellier · Academic / Other
• Sex: Female
• Age: 18 Years – 39 Years
• Healthy volunteers: Accepted

Summary

Introduction: The C-HEALTH study investigates how environmental and socio-economic conditions affect women's menstrual cycles and reproductive health. Aim: To compare progesterone levels during the luteal phase among women from different socio-economic backgrounds living in rural and urban areas in southern France. Methods: This is a prospective observational study involving 320 healthy women of reproductive age. * Hormones (progesterone, estradiol) will be measured daily in saliva. * Inflammation (Protéine C Réactive: CRP) will be measured five times per cycle via blood drops. * Participants will wear a smart ring to monitor body temperature and activity. * Daily symptoms and lifestyle data will be collected. * Environmental exposures (pollution, stress, living conditions) will be assessed and linked to menstrual health outcomes.

Detailed description

Introduction: Menstrual health is an important indicator of women's overall health, but the biological and environmental factors influencing the menstrual cycle are still poorly understood. The C-HEALTH study explores how social and ecological conditions - such as pollution, stress, socio-economic status, and living environment - affect hormonal patterns and menstrual health in women living in the Occitanie region (France). Aim: The primary objective is to compare luteal phase progesterone levels among women from different socio-economic backgrounds living in either rural or urban areas in the Occitanie region. The secondary objectives are: * To compare, according to the women's environment: levels of sex hormones (progesterone and estradiol) throughout a menstrual cycle, levels of an inflammation marker (C-reactive protein) throughout a menstrual cycle, and the description of the menstrual cycle (characteristics, possible abnormalities such as pain, abnormal bleeding, etc.). * To identify environmental factors associated with potential biological and menstrual cycle abnormalities. Methods: To meet the objectives of this research, 80 women aged 18-45 living in Occitanie (France) will be enrolled in each socioeconomic group at each location (4 groups: low-income urban, high-income urban, low-income rural, high-income rural; total n=320). After the inclusion visit (visit 1) and the training visit for self-sampling (visit 2), participants will collect their biological samples and data during one observed menstrual cycle, with a follow-up visit on day 7 of the cycle (visit 3), and will complete their participation with the collection of biological samples at home (visit 4). Biological samples (saliva and dried blood spots) will be collected no later than 30 days after the end of the collection period. The exposome matrix will be inferred using postcode and will include data from an air pollution database (Environment Data Management System - EDMS) linked primarily to traffic, industry, stationary fuel burners, forest fires and solid fuel combustion, comfort parameters (temperature, humidity), UV, pollen count, green, grey and blue spaces, vegetation, Shannon biodiversity index, noise, water quality (pesticides, heavy metals) At the end of this study: * Saliva samples will be analyzed using ELISA tests to measure steroid levels. * Dried blood spot samples will be analyzed using immunoenzymatic assays to measure CRP levels, using the ELISA technique. * The exposome will be analyzed using classical statistics, clustering/PCA (Principal Component Analysis) to assess exposure profiles, and EnWAS will be used to untangle independent associations between exposure variables and menstrual cycle parameters. A series of minimally adjusted univariate analyses will be performed and exposures significant at the false discovery rate will be retained in the cluster analysis. Within each cluster, a multivariable analysis will be performed to reduce the number of variables of interest. This will allow us to identify exposome factors independently associated with menstrual health.

Conditions

• Woman of Reproductive Age
• Socioeconomic Factors

Interventions

Type	Name	Description
OTHER	Self-saliva sampling	Self-saliva samples are taken every day from D1 inclusive over 1 consecutive cycle, to measure progesterone (P4) and estradiol (E2) concentrations.
OTHER	Self-collection of dried blood spots	Self-blood sampling is done 5 times during the cycle to measure protéine C-Réactive (CRP) concentrations.
OTHER	Wearing the connected ring	A connected ring is worn every day of the observed cycle, while maintaining lifestyle habits, to measure daily body temperature, assess heart rate variability and resting heart rate, evaluate physical activity and energy expenditure, assess stress level, and evaluate sleep quality.
OTHER	Ovulation test	An ovulation test (Ovulatest®) is carried out from day 7 until a test is positive, or until day 39 if ovulation is not detected

Timeline

• Start date: 2025-09-01
• Primary completion: 2029-07-01
• Completion: 2029-07-01
• First posted: 2025-06-25
• Last updated: 2025-11-28

Locations

1 site across 1 country: France