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NCT Number: NCT07037082

Understanding Cycles to Improve Women's Health

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.

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Key information

Conditions

Woman of Reproductive Age Inflammation Pathologic Processes Pathological Conditions, Signs and Symptoms Socioeconomic Factors

Age range

18 year–39 year

Sex eligibility

Female

Study type

Observational

Primary location

Institute of Evolutionary Science of Montpellier

Montpellier, 34090, France

Location status: Recruiting

Location contact

Alexandra ALVERGNE, PhD

CONTACT

[email protected]

+33467144966

Alexandra ALVERGNE, pHD

SUB_INVESTIGATOR

Charlotte FAURIE, MD

PRINCIPAL_INVESTIGATOR

Valérie DURAND, AE

SUB_INVESTIGATOR

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Self-saliva sampling

Other

Self-saliva samples are taken every day from D1 inclusive over 1 consecutive cycle, to measure progesterone (P4) and estradiol (E2) concentrations.

Self-collection of dried blood spots

Other

Self-blood sampling is done 5 times during the cycle to measure protéine C-Réactive (CRP) concentrations.

Wearing the connected ring

Other

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.

Ovulation test

Other

An ovulation test (Ovulatest®) is carried out from day 7 until a test is positive, or until day 39 if ovulation is not detected

Primary outcomes

  1. Mean Luteal Phase Salivary Progesterone

    Time frame: One menstrual cycle (up to 45 days)

    Mean salivary progesterone concentration (pg/mL) measured during the luteal phase - from the day after ovulation (Day of Ovulation, Jov) to the end of the menstrual cycle, or from day 32 to 45 if ovulation is not detected. The outcome is used to compare hormonal levels between women of low vs. high socioeconomic status living in rural (Environment 1) or urban (Environment 2) areas in the Occitanie region

Secondary outcomes

  1. Progesterone levels

    Time frame: One menstrual cycle (up to 45 days)

    Progesterone levels (pg/ml) will be measured in saliva every day of the observed cycle.

    Averages will be calculated over 7 periods of the cycle:

    • Follicular Average
    • Follicular Peak Average
    • Luteal Average
    • Luteal Peak Average
    • Preovulatory Average*
    • Periovulatory Average*
    • Postovulatory Week 1 Average*
    • Postovulatory Week 2 Average*
    • Postovulatory Week 3 Average* (* for ovulatory cycles only)

  2. Estradiol levels

    Time frame: One menstrual cycle (up to 45 days)

    Estradiol levels (pg/ml) will be measured in saliva every day of the observed cycle.

    Averages will be calculated during 7 periods of the cycle:

    • Follicular Average
    • Follicular Peak Average
    • Luteal Average
    • Luteal Peak Average
    • Preovulatory Average*
    • Periovulatory Average*
    • Postovulatory Week 1 Average*
    • Postovulatory Week 2 Average*
    • Postovulatory Week 3 Average* (* for ovulatory cycles only)

  3. Protéine C Réactive (CRP) levels

    Time frame: Day 2, Day 7, Day of ovulation (or Day 32 if ovulation is not detected), 7 days after ovulation (or Day 39 if ovulation is not detected), 12 days after ovulation (or Day 44 if ovulation is not detected)

    CRP levels (mg/L) will be measured in the blood at 5 points during the observed cycle:

    • Day 2 (D2)
    • Day 7 (D7)
    • Day of ovulation (Dov) or Day 32 (D32=D45-13) if ovulation is not detected
    • at the Luteal Peak on Dov+7 or Day 39 (D39=D45-6) if ovulation is not detected
    • in the premenstrual phase on Dov+12 or Day 44 (D44=D45-1) if ovulation is not detected
    • Difference in CRP will be measured between D2 and Dov+7, or between D2 and D39 if ovulation is not detected

  4. The length of cycles

    Time frame: Day 0

    The length (in days) of the 3 cycles preceding the observed cycle

  5. Period frequency

    Time frame: Day 0 and the day before the next cycle

    Period frequency in the observed cycle (calculated as the length of a cycle: Duration between the first day of the observed cycle (D0) and the day before the first day of the next cycle).

    • Amenorrhea: no bleeding
    • Infrequent: > 38 days
    • Normal: 24 to 38 days
    • Frequent: < 24 days

  6. Cycle regularity

    Time frame: Day 0 and the day before the first day of the next cycle

    Cycle regularity over the observed cycle and the three previous cycles:

    Difference (in days) between the longest and shortest cycle over four continuous cycles.

    • Normal or regular: difference ≤ 7-9 days)
    • Irregular: difference ≥ 10 days)

  7. Duration of the period

    Time frame: Day 0 and the last day of menstruation (up to 45 days)

    The duration of the period in the observed cycle (in days).

    • Amenorrhea: 0 days
    • Normal: ≤ 8 days
    • Prolonged: > 8 days

  8. Flow abundance

    Time frame: Day 0 and the last day of menstruation (up to 45 days)

    Flow abundance (heavy/light) Heavy periods are defined as the need to change a sanitary napkin or tampon every 1 or 2 hours.

  9. Score Higham

    Time frame: Day 0 and the last day of menstruation (up to Day 45)

    Score Higham is an objective assessment of menstrual blood loss based on the number of sanitary pads used and clots passed, to classify periods are light, normal or heavy.

    Score interpretation:

    • 100 points: blood loss of at least 80 mL, indicating menorrhagia.
    • 150 points: potential indication for surgical intervention in menometrorrhagia.

  10. Ovulation test

    Time frame: Day 7 to positive test (up to Day 45) or until Day 39 if ovulation is not detected

    Ovulatest® ovulation test performed from Day 7 until a positive test is obtained, or until Day 39 (D39=Day 45-6) if ovulation is not detected. Ovulation is considered the day following the positive test.

  11. Body temperature

    Time frame: One menstrual cycle (up to 45 days)

    Body temperature will be recorded on a smart ring throughout the observed cycle. Ovulation will be detected by an increase of at least 0.3°C by the smart ring.

  12. Length of the luteal phase

    Time frame: First Day of ovulation and the day before the first day of the following cycle (up to Day 45), only if ovulation is detected

    Length of the luteal phase (in days), defined as the number of days between Dov (inclusive, measured by the first positive Ovulatest®) and the last day of the cycle.

    • ≤ 10 days: short luteal phase
    • > 10 days: normal luteal phase (Practice Committees of the American Society for Reproductive Medicine and the Society for Reproductive Endocrinology and Infertility, 2021)

  13. Intermenstrual bleeding

    Time frame: One menstrual cycle (up to 45 days)

    Presence of intermenstrual bleeding in the observed cycle (yes/no, and if yes, specify cycle day/date)

  14. Premenstrual symptoms Intensity

    Time frame: Day 12 and 12 days after ovulation (or Day 44 if ovulation is not detected)

    Premenstrual symptoms intensity will be assessed over the observed cycle:

    • On Day 12 for the period between Days 6 and 12 (mid-follicular phase),
    • On Day 12 (Days 6 to 12) or Day 44 (Days 38 to 44) if ovulation is not detected.

    16 symptoms (sweet cravings, increased appetite, mood swings/anxiety, fatigue, breast tenderness, weight gain, bloating, constipation or diarrhea, abdominal pain, headaches, sleep problems, inattention/distraction, hot flashes, decreased libido, oily hair, skin irritation) will be rated on a Likert scale from 1 to 5 (1=No symptoms; 2=Mild symptoms; 3=Moderate symptoms; 4=Severe symptoms; 5=Very severe symptoms).

  15. Pain during menstruation

    Time frame: Day 2

    Pain during menstruation will be assessed on Day 2 of the observed cycle using a visual numeric scale (VNS) from 0 to 10.

Study contacts

Contact information is provided by the study sponsor or research team.

Alexandra ALVERGNE, PhD

CONTACT

[email protected]

+33467144966

Charlotte FAURIE, MD

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

University Hospital, Montpellier

Other

Collaborators

  • Centre National de la Recherche Scientifique, France
  • Institut National de la Santé Et de la Recherche Médicale, France
  • Institute of Evolutionary Science of Montpellier
  • National Research Agency, France
  • Université Montpellier

Registry information

Official study title

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

Acronym: C-HEALTH

Important dates

Study start
2025
Primary completion
2029
Study completion
2029
First posted
Jun 25, 2025
Registry last updated
Jun 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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