Breathing for Two: Can inspiratory muscle training help with blood pressure in late pregnancy?

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

In this early-phase trial, pregnant participants in their third trimester are randomized to perform moderate or minimal resistance inspiratory muscle strength training for 5 to 8 minutes daily over six weeks. The intervention uses IMST at 15% or 50% of each participant's PI max to see if it can improve blood pressure and vascular health without compromising safety. A sham condition serves as a comparator to gauge the training’s true effect. Eligible participants must be 18–55 years old, with singleton gestation, and able to use Bluetooth-enabled devices and complete online surveys. The study takes place at Banner University Medical Center in Tucson, with the University of Arizona leading the effort.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* 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
* 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

Exclusion Criteria:

* 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
* 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)

Where it's running

• Banner University Medical Center
  Tucson, Arizona, United States Recruiting

Study contacts

• Study coordinator: Elise Erickson, PhD
• Email: eliseerickson@arizona.edu
• Phone: 520-621-1139

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Arm versus ankle mean arterial pressure during elective cesarean delivery

  This study will see if a blood pressure cuff on the ankle gives similar mean arterial pressure readings to a standard arm cuff in pregnant people having a planned C-section under spinal anesthesia.

  Recruiting St. Justine's Hospital · Montreal, Quebec · NCT07422766

• How arm position changes blood pressure readings during pregnancy

  We will see if different arm positions (supported at heart level, on the lap, or unsupported at the side) change blood pressure readings in pregnant women attending a high-risk clinic.

  Recruiting Sheba Medical Center · Ramat Gan · NCT07405723

• Pregnant Women Living with HIV on Bictegravir/Emtricitabine/Tenofovir Alafenamide

  This study looks at how B/F/TAF is used in pregnant women with HIV and whether it helps maintain viral suppression from before conception through delivery.

  Recruiting Centre de Recherches et d'Etude sur la Pathologie Tropicale et le Sida · Paris · NCT07921472

• Pelvic Floor Training and a Modified Lumbopelvic Belt for Symphysis Pubis Pain in Pregnancy

  This study tests whether pelvic floor muscle training plus a modified lumbopelvic belt can reduce pain and improve function for pregnant women with symphysis pubis pain.

  Recruiting Kahramanmaras Sutcu Imam University · Kahramanmaraş · NCT07919548

• Effective Communication in VBAC Counseling

  This study tests how clearly doctors and midwives explain VBAC options during prenatal visits and whether patients feel understood.

  Recruiting IRCCS San Raffaele · Milan, MI · NCT07919145

• Innovative Multidisciplinary and Virtual Care for IBD in Pregnancy

  This study tests a dedicated IBD pregnancy care model, including a new virtual approach, to see if it improves access and quality of care for pregnant people with Crohn's disease or ulcerative colitis.

  Recruiting at 5 sites Austin Health · Hobart and 6 other locations · NCT07916727

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.