Actively Recruiting
Validation of Effectiveness on NaturalCycles Users
Led by Natural Cycles · Updated on 2026-05-08
2000
Participants Needed
1
Research Sites
135 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
The goal of this observational study is to measure the effectiveness of the Natural Cycles digital birth control application at preventing pregnancy in sexually active women aged 18 to 35 with no known history of infertility. The main questions it aims to answer are: * What is the pregnancy rate of the application over one year, for all users? * What is the pregnancy rate of the application over one year, for users who follow the application's instructions perfectly? Participants will: * Use the Natural Cycles application for birth control for up to one year. * Log information about daily sexual activity in the app. * Complete a questionnaire at the beginning and end of their participation. * Perform urine pregnancy tests (provided by mail) upon entry to the study, at the start of every cycle during the study, and upon exit from the study.
CONDITIONS
Official Title
Validation of Effectiveness on NaturalCycles Users
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Wants to avoid pregnancy for 13 cycles
- Willing to rely solely on Natural Cycles as the only contraception method for 13 cycles
- Not currently using permanent contraceptive methods such as sterilization or hormonal methods like implant or IUD
- Has an intact uterus, both ovaries, and both fallopian tubes to the best of their knowledge
- Has an average menstrual cycle length between 21 and 35 days
- Anticipates heterosexual intercourse at least once a month in the next year
- Willing to enter daily data and perform pregnancy tests as requested
- Willing to complete a satisfaction survey at the end of participation
You will not qualify if you...
- Has EU citizenship
- Received a Depo-Provera injection in the last 10 months or has had fewer than three consecutive spontaneous menstrual cycles since the last injection
- Has had fewer than three consecutive spontaneous menstrual cycles after removing a hormonal implant
- Has had fewer than three consecutive spontaneous menstrual cycles after pregnancy
- Has had fewer than three consecutive spontaneous menstrual cycles since last breastfeeding
- Has known fertility issues or has been advised by a healthcare professional about possible difficulty conceiving
- Has medical conditions affecting fertility such as endometriosis, Pelvic Inflammatory Disease, significant uterine fibroids or adenomyosis
- Regularly takes prescribed medications known to cause birth defects, including isotretinoin, valproic acid or divalproex sodium, methotrexate or leflunomide, ACE inhibitors or ARBs, or warfarin
AI-Screening
AI-Powered Screening
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Trial Site Locations
Total: 1 location
1
Natural Cycles USA Corp
New York, New York, United States, 10036
Actively Recruiting
Research Team
A
Agathe van Lamsweerde, MSc
CONTACT
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
1
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