Actively Recruiting
Influences of Long-acting Reversible Contraceptives on Iron Status and Physiological Responses to Extreme Environments in Women
Led by United States Army Research Institute of Environmental Medicine · Updated on 2026-04-30
33
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are studying how long-acting reversible contraceptives (LARCs), such as implants and intrauterine devices, affect iron levels and how women's bodies respond to extreme environments like heat, cold, and high altitude. The study focuses on female military personnel and civilians aged 18 to 40 years. It aims to understand if using LARCs influences physiological reactions, such as sweating, skin blood flow, breathing, and heart rate, and to explore the prevalence of iron deficiency and anemia in women using these contraceptives compared to those using short-acting methods like oral contraceptives.
CONDITIONS
Brief Title
Influences of Long-acting Reversible Contraceptives on Iron Status and Physiological Responses to Extreme Environments in Women
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Female, aged 18 to 40 years
- Using monophasic oral contraceptives or implantable contraception (IUD, implant) for at least one year
- At least one year removed from contraceptive removal endpoint
- In good health as determined by medical oversight
- Passed most recent Army Combat Fitness Test or exercises at least twice weekly
- Willing to avoid alcohol for 24 hours before testing
- Willing to avoid caffeine for 12 hours before testing
- Willing to refrain from moderate to strenuous exercise 24 hours prior to testing
- Willing to stay and exercise in an altitude chamber for about 6 hours
- Has supervisor approval if a federal civilian employee or non-HRV active-duty military personnel stationed at NSSC
You will not qualify if you...
- Pregnant, planning pregnancy, or breastfeeding
- Taking medications or supplements other than contraceptives without approval
- Tobacco or nicotine user within last 4 months
- Physical injuries affecting treadmill walking or running
- Allergy to skin adhesive
- Heart, lung, kidney, muscle, endocrine, or nerve disorders
- History of heat or orthostatic intolerance
- Diagnosed or treated for fluid/electrolyte imbalance in last 30 days
- History of gastrointestinal obstructive diseases
- Scheduled MRI within 2 weeks after heat or cold test
- Actively dieting to lose weight
- History of cold injuries or Raynaud's syndrome
- Cold-induced asthma or bronchospasm
- Unwilling to have small skin areas shaved if needed
- Born at altitudes above 2,100 m
- Living or traveled to altitudes above 1,200 m recently
- Prior diagnosis of high-altitude pulmonary or cerebral edema
- Abnormal blood counts or blood chemistry
- History of pneumothorax or hypertension
- Blood donation within 8 weeks before study
- Recent or expected prolonged immobility
- Evidence of sleep disorders like apnea or narcolepsy
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Approximately 6 to 7 hours during environmental exposure testing
Participants undergo testing of blood volume, iron stores, and physiological responses to acute environmental exposures including heat, cold, and high-altitude, each environment tested independently.
1 to 3 visits depending on environmental exposures tested
Trial Site Locations
Total: 1 location
1
US Army Research Institute of Environmental Medicine
Natick, Massachusetts, United States, 01760
Actively Recruiting
Research Team
G
Gabrielle E Giersch, PhD
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
2
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