MenstruationNCT05852951
Cycle and Ovulation Study Expansion
An observational study of Menstruation, run by Apple Inc. at 1 site in United States.
Trial summary
The objective of this study was to collect menstrual cycle, health sensor data and general health information to understand correlations between menstrual cycle and health sensor data, and how those correlations may be affected by general health. Read more about this study
- Who is it for?
- Ages 14 years and older, women only
- Conditions the study is for
- Menstruation
- How many people
- 698 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Jun 2021to 23 May 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 14 years and older
- Women only
- No healthy volunteers
- Child, Adult, Older adult
Study population: Contract research organization
- At least 14 years of age (19 for residents of Alabama and Nebraska and 21 for residents of Mississippi)
- Can communicate in written and spoken English
- Own functioning iPhone iOS 14 or later, with access to reliable data plan and Wifi
- Access to reliable Wifi in the bedroom
- Willingness to participate in remote visits and follow study procedures for the duration of the study, including use of Apple Watch and a wrist-work hardware prototype
- Able to read and understand the written consent form
- Reside in the US for the duration of the study
Trial locations and contacts
1 site in 1 country.
About this study
The objective of this study was to collect menstrual cycle, health sensor data and general health information to understand correlations between menstrual cycle and health sensor data, and how those correlations may be affected by general health. Participants entered menstrual cycle information (such as start dates, end dates, symptoms, flow), basal body temperature as measured by a thermometer, and ovulation and progesterone test results via apps installed on their iPhone. Additionally, participants were provided with an Apple Watch and a wrist-worn hardware prototype wrist-worn sleep band to collect physiological sensor data. Both menstrual cycle information and physiological sensor data stored on the participants' iPhone prior to enrolling in the study (up to 18 months) was also collected. This study aimed to collect data from females aged 14 and older who are currently menstruating with irregular and regular menstrual cycles.
- Conditions
- Menstruation
- Keywords
- menstruation, ovulation, menstrual cycle
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Menstrual patterns | Regular menstrual cycles and irregular menstrual cycles; irregular menstrual cycles are defined as having variation in menstrual cycles of greater than 2 days and less than 2 months |
What is being measured
The primary outcome is the main question the study is designed to answer.
Retrospective ovulation day estimate
Retrospective ovulation day estimation (algorithm uses multiple measurements including menstrual flow, urine ovulation prediction testing, basal body temperature, overnight aggregated wrist temperature)
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2023
- Study start9 Jun 2021
- Primary completion23 May 2022
- Study completion23 May 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for MenstruationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 698 participants (actual)
Sponsor and investigators
- Lead sponsor
- Apple Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Exponent
- Responsible party
- Sponsor
- Investigators
- Bo Qing, PhD, Principal investigator, Exponent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05852951
- Sponsor's protocol ID
- Pro00054031
- Status last verified
- May 2023
- First submitted
- 7 Mar 2023
- Last updated
- 10 May 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Wang Y, Park J, Zhang CY, Jukic AMZ, Baird DD, Coull BA, Hauser R, Mahalingaiah S, Zhang S, Curry CL. Performance of algorithms using wrist temperature for retrospective ovulation day estimate and next menses start day prediction: a prospective cohort study. Hum Reprod. 2025 Mar 1;40(3):469-478. doi: 10.1093/humrep/deaf005.
PubMed 39881571
Study at a glance
From the registry record, last updated by the sponsor on 10 May 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cycle and Ovulation Study Expansion
- ClinicalTrials.gov ID
- NCT05852951
- Acronym / sponsor ID
- Pro00054031
- Conditions
- Menstruation
- Keywords
- menstruation, ovulation, menstrual cycle
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 698 participants (actual)
- Lead sponsor
- Apple Inc.Industry (pharma, biotech, devices)
- Collaborators
- Exponent
- Study start
- 9 Jun 2021 (actual)
- Primary completion
- 23 May 2022 (actual)
- Study completion
- 23 May 2022 (actual)
- First posted
- 10 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The objective of this study was to collect menstrual cycle, health sensor data and general health information to understand correlations between menstrual cycle and health sensor data, and how those correlations may be affected by general health. Participants entered menstrual cycle information (such as start dates, end dates, symptoms, flow), basal body temperature as measured by a thermometer, and ovulation and progesterone test results via apps installed on their iPhone. Additionally, participants were provided with an Apple Watch and a wrist-worn hardware prototype wrist-worn sleep band to collect physiological sensor data. Both menstrual cycle information and physiological sensor data stored on the participants' iPhone prior to enrolling in the study (up to 18 months) was also collected. This study aimed to collect data from females aged 14 and older who are currently menstruating with irregular and regular menstrual cycles.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Menstrual patterns | – | –Regular menstrual cycles and irregular menstrual cycles; irregular menstrual cycles are defined as having variation in menstrual cycles of greater than 2 days and less than 2 months |
Who may qualify
- Ages
- 14 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Contract research organization
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Retrospective ovulation day estimate
Time frame: 12 months
Retrospective ovulation day estimation (algorithm uses multiple measurements including menstrual flow, urine ovulation prediction testing, basal body temperature, overnight aggregated wrist temperature)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 May 2023.
- Derived from this study: PubMed 39881571Wang Y, Park J, Zhang CY, Jukic AMZ, Baird DD, Coull BA, Hauser R, Mahalingaiah S, Zhang S, Curry CL. Performance of algorithms using wrist temperature for retrospective ovulation day estimate and next menses start day prediction: a prospective cohort study. Hum Reprod. 2025 Mar 1;40(3):469-478. doi: 10.1093/humrep/deaf005.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Bo Qing, PhD principal investigator
Exponent
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Menstruation, run by Apple Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 May 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Retrospective ovulation day estimate (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05852951, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 May 2023.