Hypertension Disorders in PregnancyEarly Phase 1NCT07687745
Breathing for Two: Inspiratory Muscle Strength Training for Supporting Healthy Blood Pressure in Pregnancy
A Early Phase 1 study testing Exercise at 15% PI max and Exercise at 50% PI max in people with Hypertension Disorders in Pregnancy and Blood Pressure Measurement in Pregnancy, run by University of Arizona at 1 site in United States.
Trial summary
This is an interventional study that will test whether a breathing exercise called Inspiratory Muscle Strength Training (IMST) can safely and effectively lower blood pressure during late pregnancy. Read more about this study
- Who is it for?
- Ages 18 to 55 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Hypertension Disorders in Pregnancy, Blood Pressure Measurement in Pregnancy, Inspiratory Strength Training (IST)
- What is being tested?
- Exercise at 15% PI max and Exercise at 50% PI max
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- 1 siteUnited States
- Study dates
- 8 Jun 2026to 30 Sep 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
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 18 to 55 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Female sex
- Pregnant (32 to 34 weeks of gestation, confirmed by ultrasound, at the time of first training session, eligible patients may consent/enrolled earlier in pregnancy)
- Singleton pregnancy
- Age 18 to 55
- Able to read English and provide consent
- Possess smartphone for syncing the AiroFit and Omron devices using Bluetooth and completing online surveys
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- Smartphone updated to iOS 12+ or Android 11+
- No contraindication for moderate exercise at time of enrollment
- Not planning delivery for at least one month at time of enrollment (< 38 weeks of gestation)
- Willing to adhere to AiroFit device use throughout study period
- Must already be scheduled, or in the process of scheduling, for weekly NST appointments by 32 to 34 weeks gestational age (per provider order / due to obstetric indication)
- Lower-Risk Pregnancy Cohort Inclusion Criteria:
- No history or evidence of hypertensive disorders of pregnancy
- May be undergoing antenatal testing for:
- Conception via in vitro fertilization, BMI ≥ 35, an advanced maternal age (age >/=35), or other condition not listed in exclusion criteria or 'higher risk for HDP group' but is recommended for antenatal testing.
- Higher-Risk Pregnancy Cohort Inclusion Criteria:
- Conditions associated with higher risk of developing HDP, including:
- Gestational diabetes mellitus, chronic hypertension, gestational hypertension, or a history of preeclampsia in a previous pregnancy
Who cannot join
- Younger than 18 or older than 55 years of age
- Multiple gestation (twin or higher-order pregnancy)
- Fetal chromosomal abnormalities or major anatomical anomalies
- Planning to deliver earlier than 38 weeks or within 4 weeks of study enrollment
- Any contraindication for moderate exercise (e.g., cardiomyopathy, congenital cardiac conditions)
- Deep vein thrombosis
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- Complications in current pregnancy including intrauterine growth restriction (IUGR), oligohydramnios, preeclampsia, or severe-range blood pressures (>/=160/110 or <100/60)
- Active vaginal bleeding, or history of coagulopathy
- Placenta previa or other placental abnormalities (including placental cyst or abruption)
- Signs of labor
- Current substance use disorder
- History of neurological, respiratory, head/neck, or thoracic surgeries, or conditions such as collapsed lung or perforated eardrum
- Individuals with any of the following:
- Chronic obstructive pulmonary disorder (COPD)
- Severe asthma
- Severe ischemic heart disease
- Left-sided heart failure
- Chronic laryngitis, chronic bronchitis, emphysema, pneumonia
- Latent or active tuberculosis
- Chronic cough
- Neurological problems (e.g. seizure disorder)
- Severe scoliosis with no history of surgical correction or management.
- Organ transplant
- HIV or other immunocompromising conditions
- Autoimmune disease with possible vascular complications (e.g. Lupus)
- Significant respiratory compromise (e.g., severe dyspnea, O₂ saturation <95%, uncontrolled asthma, history of pneumothorax)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Banner University Medical Center
Tucson, Arizona, 85719
Rachel Darche, MD, 520-621-1139, rldarche@arizona.edu
About this study
This is an interventional study that will test whether a breathing exercise called Inspiratory Muscle Strength Training (IMST) can safely and effectively lower blood pressure during late pregnancy. The goal is to see if a home-based breathing training can help prevent or reduce high blood pressure disorders in pregnancy. The main objectives are to make sure the training is safe and tolerable for pregnant women and to examine blood pressure and blood vessel health. Participants in their third trimester will be randomly assigned to either do moderate resistance IMST or a minimal resistance sham IMST, for 5 to 8 minutes a day over six weeks.
- Conditions
- Hypertension Disorders in Pregnancy, Blood Pressure Measurement in Pregnancy, Inspiratory Strength Training (IST), Pregnancy
- Being tested
- Exercise at 15% PI max, Exercise at 50% PI max
- Keywords
- pregnancy, blood pressure, hypertensive disorders of pregnancy, imst, hdp, inspiratory muscle strength training
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exercise at 15% PI maxOther
Minimal resistance training, similar to yoga, for 5 to 8 minutes a day over six weeks.
Exercise at 50% PI maxOther
Moderate resistance training, similar to strength training for 5 to 8 minutes a day over six weeks.
| Study group | Role | What they receive |
|---|---|---|
| Low-Resistance IMST | Sham comparator | Not described Receives: Other: Exercise at 15% PI max |
| Moderate-Resistance IMST | Active comparator | Not described Receives: Other: Exercise at 50% PI max |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Maternal and Fetal Safety Events During Inspiratory Muscle Strength Training (IMST)
Percentage of training sessions associated with abnormal post-training fetal heart rate (FHR) tracing, or with maternal oxygen desaturation (SpO2) or symptoms (e.g., perceived exertion, lightheadedness, hyperventilation), as assessed by study staff during non-stress test (NST) and clinic visits.
Measured: 6 weeks
Adherence to IMST Training and Home Blood Pressure (BP) Monitoring
Percentage of prescribed daily IMST training sessions and daily home BP measurements completed by each participant, as captured via training device data and MyCap entries.
Measured: 6 weeks
Change from Baseline in Systolic Blood Pressure
Change in systolic BP (mmHg), measured via validated automated oscillometric sphygmomanometer (Omron BP7450) per ESH-IP protocol, comparing IMST and sham IMST groups.
Measured: 6 weeks
Change from Baseline in Endothelial Function as Assessed by Post-Occlusive Reactive Hyperemia (PORH)
Change in cutaneous microvascular blood flow response (perfusion units) following brief arterial occlusion, measured via Laser Doppler Blood FlowMetry, comparing IMST and sham IMST groups.
Measured: 6 weeks
Change from Baseline in Urinary Nitrite/Nitrate Concentration
6 weeks
Measured: Change in urinary nitrite/nitrate concentration (µM), measured weekly via Griess colorimetric assay (Cayman Nitrite Colorimetric Assay), as an indirect marker of nitric oxide bioavailability.
Secondary outcomes (3)
Change from Baseline in Perceived Sleep Quality
Change in self-reported sleep quality as measured by the PROMIS Sleep Disturbance short form, administered weekly via MyCap.
Measured: 6 weeks
Change from Baseline in Dyspnea Severity
Change in self-reported shortness of breath severity as measured by the PROMIS Dyspnea Severity items, administered weekly via MyCap.
Measured: 6 weeks
Change from Baseline in Perceived Stress
Change in perceived stress as measured by the Perceived Stress Scale (PSS), administered weekly via MyCap.
Measured: 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jul 2026
- Study start8 Jun 2026
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hypertension Disorders in PregnancyStudies of the same condition, open and under way.
- More trials run by University of ArizonaThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Arizona
- Sponsor type
- University, hospital or other
- Collaborators
- Banner University Medical Center
- Responsible party
- Principal investigator, Elise Erickson, University of Arizona
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07687745
- Sponsor's protocol ID
- STUDY00007216
- Status last verified
- Jul 2026
- First submitted
- 8 Jun 2026
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: All IPD that underlie results in a publication will be shared, after any identifying information is removed from the dataset.
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Breathing for Two: Inspiratory Muscle Strength Training for Supporting Healthy Blood Pressure in Pregnancy
- ClinicalTrials.gov ID
- NCT07687745
- Acronym / sponsor ID
- STUDY00007216
- Conditions
- Hypertension Disorders in Pregnancy, Blood Pressure Measurement in Pregnancy, Inspiratory Strength Training (IST), Pregnancy
- Keywords
- pregnancy, blood pressure, hypertensive disorders of pregnancy, imst, hdp, inspiratory muscle strength training
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- University of ArizonaUniversity, hospital or other
- Collaborators
- Banner University Medical Center
- Study start
- 8 Jun 2026 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Sep 2027 (estimated)
- First posted
- 7 Jul 2026 (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.
This is an interventional study that will test whether a breathing exercise called Inspiratory Muscle Strength Training (IMST) can safely and effectively lower blood pressure during late pregnancy. The goal is to see if a home-based breathing training can help prevent or reduce high blood pressure disorders in pregnancy. The main objectives are to make sure the training is safe and tolerable for pregnant women and to examine blood pressure and blood vessel health. Participants in their third trimester will be randomly assigned to either do moderate resistance IMST or a minimal resistance sham IMST, for 5 to 8 minutes a day over six weeks.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Low-Resistance IMST | Sham comparator | Other: Exercise at 15% PI max |
| Moderate-Resistance IMST | Active comparator | Other: Exercise at 50% PI max |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (18 listed)
- Female sex
- Pregnant (32 to 34 weeks of gestation, confirmed by ultrasound, at the time of first training session, eligible patients may consent/enrolled earlier in pregnancy)
- Singleton pregnancy
- Age 18 to 55
- Able to read English and provide consent
Key exclusion criteria (26 listed)
- Younger than 18 or older than 55 years of age
- Multiple gestation (twin or higher-order pregnancy)
- Fetal chromosomal abnormalities or major anatomical anomalies
- Planning to deliver earlier than 38 weeks or within 4 weeks of study enrollment
- Any contraindication for moderate exercise (e.g., cardiomyopathy, congenital cardiac conditions)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Exercise at 15% PI maxMinimal resistance training, similar to yoga, for 5 to 8 minutes a day over six weeks. | Other | Low-Resistance IMST |
| Exercise at 50% PI maxModerate resistance training, similar to strength training for 5 to 8 minutes a day over six weeks. | Other | Moderate-Resistance IMST |
Primary outcome
Incidence of Maternal and Fetal Safety Events During Inspiratory Muscle Strength Training (IMST)
Time frame: 6 weeks
Percentage of training sessions associated with abnormal post-training fetal heart rate (FHR) tracing, or with maternal oxygen desaturation (SpO2) or symptoms (e.g., perceived exertion, lightheadedness, hyperventilation), as assessed by study staff during non-stress test (NST) and clinic visits.
Adherence to IMST Training and Home Blood Pressure (BP) Monitoring
Time frame: 6 weeks
Percentage of prescribed daily IMST training sessions and daily home BP measurements completed by each participant, as captured via training device data and MyCap entries.
Change from Baseline in Systolic Blood Pressure
Time frame: 6 weeks
Change in systolic BP (mmHg), measured via validated automated oscillometric sphygmomanometer (Omron BP7450) per ESH-IP protocol, comparing IMST and sham IMST groups.
Change from Baseline in Endothelial Function as Assessed by Post-Occlusive Reactive Hyperemia (PORH)
Time frame: 6 weeks
Change in cutaneous microvascular blood flow response (perfusion units) following brief arterial occlusion, measured via Laser Doppler Blood FlowMetry, comparing IMST and sham IMST groups.
Change from Baseline in Urinary Nitrite/Nitrate Concentration
Time frame: Change in urinary nitrite/nitrate concentration (µM), measured weekly via Griess colorimetric assay (Cayman Nitrite Colorimetric Assay), as an indirect marker of nitric oxide bioavailability.
6 weeks
3 secondary outcomes
Change from Baseline in Perceived Sleep Quality
Time frame: 6 weeks
Change from Baseline in Dyspnea Severity
Time frame: 6 weeks
Change from Baseline in Perceived Stress
Time frame: 6 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. All IPD that underlie results in a publication will be shared, after any identifying information is removed from the dataset.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Exercise at 15% PI max and Exercise at 50% PI max in people with Hypertension Disorders in Pregnancy and Blood Pressure Measurement in Pregnancy, run by University of Arizona 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?
The sponsor lists 18 inclusion and 26 exclusion criteria. 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: looking for participants now, as of the sponsor's last update on 7 Jul 2026. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Elise Erickson, PhD (520-621-1139, eliseerickson@arizona.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Maternal and Fetal Safety Events During Inspiratory Muscle Strength Training (IMST) (time frame: 6 weeks). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 7 Jul 2026.