Woman of Reproductive Age

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.