How menstrual cycles relate to women's health in southern France

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

Observational University Hospital, Montpellier · NCT07037082

This research will try to see if environmental and socioeconomic differences between rural and urban areas of southern France change luteal progesterone levels and menstrual symptoms in women of reproductive age.

Quick facts

Study typeObservational
Enrollment320 (estimated)
Ages18 Years to 39 Years
SexFemale
SponsorUniversity Hospital, Montpellier Academic / other
Locations1 site (Montpellier)
Trial IDNCT07037082 on ClinicalTrials.gov

What this trial studies

The C-HEALTH project is a prospective observational cohort enrolling 320 healthy women aged 18–39 in Occitanie divided into four groups by income and rural/urban residence. Participants will collect daily salivary hormones (progesterone, estradiol), provide dried blood spots for CRP five times per cycle, use ovulation tests, wear a smart ring for temperature and activity monitoring, and log daily symptoms and lifestyle factors. Environmental exposures such as pollution, stress, and living conditions will be characterized and linked to hormonal, inflammatory, and menstrual cycle outcomes. The primary comparison is luteal-phase progesterone across socioeconomic and location groups, with secondary analyses of estradiol, CRP, cycle characteristics, and exposure associations.

Who should consider this trial

Good fit: Ideal candidates are healthy women aged 18–39 who have not used hormonal contraception for at least six months, have semi-regular cycles (21–45 days), live and work in the same rural or urban area in Occitanie, can perform self-sampling, and have access to a -20°C freezer.

Not a fit: Women with diagnosed conditions such as PCOS, endometriosis, major chronic diseases, current hormonal contraception use, irregular cycles, infertility history, or those living outside Occitanie are unlikely to gain direct benefit from participation.

Why it matters

Potential benefit: If successful, the findings could reveal environmental or social factors that influence menstrual hormones and symptoms and inform prevention, public health measures, and tailored patient guidance.

How similar studies have performed: Prior research has linked environmental exposures to menstrual outcomes, but combining daily salivary hormones, serial dried-blood CRP, wearable physiological data, and detailed socioeconomic/rural–urban grouping is relatively novel.

Eligibility criteria

Show full inclusion / exclusion 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

Where this trial is running

Montpellier

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Woman of Reproductive AgeSocioeconomic FactorsMenstrual CycleExposomeHormonesInflammationRural/UrbanSocioeconomic status
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.