Understanding Cycles to Improve Women's Health

Launched by UNIVERSITY HOSPITAL, MONTPELLIER · Jun 16, 2025

Keywords

ClinConnect Summary

This study, called C-HEALTH, is looking at how a woman’s environment and social background might affect her menstrual cycle and overall reproductive health. Researchers want to understand if progesterone—a hormone important for the second half of the menstrual cycle—varies between women living in rural versus urban areas and from different socioeconomic backgrounds in southern France.

The study plans to include 320 healthy women aged 18 to 39 who have regular menstrual cycles and are not using hormonal birth control. Participants will be asked to collect saliva samples daily to measure hormone levels, provide small blood samples a few times per cycle to check inflammation, and wear a smart ring to track their body temperature and activity. They will also record daily symptoms and lifestyle habits, while the researchers will look at environmental factors like pollution and stress. This study is not yet recruiting, and women who are pregnant, breastfeeding, or have certain health conditions won’t be able to participate. The goal is to better understand how different living conditions affect women’s reproductive health, which could help improve health care and support for women in the future.

Gender

FEMALE

Eligibility criteria

• Inclusion Criteria:
• • Woman of childbearing age (18-39 years)
• • Woman not using hormonal contraception for at least 6 months
• • Woman with semi-regular menstrual cycles between 21 and 45 days inclusive
• • Woman with no known history of infertility
• • Woman working in the same environment (urban/rural) as her place of residence
• • Knowledge of the dates of periods over the last 3 cycles
• • Woman who has a freezer at -20°C
• Exclusion Criteria:
• • Diagnosis by a physician of one or more of the following comorbidities: Polycystic ovarian syndrome (PCOS), Endometriosis, Adenomyosis, Diabetes or thyroid disease, Hormone-dependent gynecological cancers (breast, endometrium, ovaries), Coagulation diseases (von Willebrand), Chronic liver failure, chronic renal failure, heart disease, autoimmune disease, Autism, Diagnosis and/or treatment for a psychiatric illness
• • Chronic exposure to cocaine, amphetamine/methamphetamine, morphine or ecstasy within 30 days prior to inclusion
• • Chronic exposure to THC within 7 days prior to inclusion.
• • Person who is not comfortable with self-sampling (hematophobia or other)
• • No access to a smartphone
• • No possibility of wearing a connected ring for at least 60 days 22h/24h
• • Pregnant or breastfeeding woman
• • Woman who gave birth or breastfed in the 2 months before the study
• • Person who moved less than 2 years before the study (does not concern participants who moved in the same environment (rural or urban, less than 20 km)
• • Person unable to read French
• • Failure to obtain informed consent
• • Person not benefiting from a national health insurance scheme
• • Person under legal protection, guardianship or curatorship
• • Person participating in other research involving the human person