Taking people in United StatesNo phase

Leg Heating Tested in Pregnant Women With Obesity

Tests home leg heating in pregnant women with obesity, to study blood vessels.

Key facts

Who runs it: University of Texas Southwestern Medical Center
Where: Dallas, United StatesSee the site
Trial code: NCT06932250
Registry title: Leg Heating in Pregnant Women With Obesity
Status: Recruiting
People taking part: 118 people, planned
Started: 1 Aug 2025
Expected to end: 30 Apr 2030
Type of study: Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested: Leg heating
Record updated: 17 April 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for pregnant women aged 18-45 years with overweight or obesity, at 10-14 weeks of pregnancy. It tests home leg heating with a sauna blanket.

Age: 18-45 years
Sex: Women only
Disease stage: Pregnant, 10-14 weeks of gestation, with a pre-pregnancy body mass index of 25 kg/m2 or more. Normal or somewhat high blood pressure is allowed.
Earlier treatment: Women must not be taking any blood pressure medicine. Low-dose aspirin is allowed.

Main reasons for not taking part

Twin or other multiple pregnancy
Diabetes
Cardiovascular, lung or brain and nerve disease
Kidney disease (serum creatinine above 0.9 mg/dL (80 µmol/L))
Current tobacco use

This trial only enrols pregnant participants. The registry sentence this rests on: Women with overweight or obesity (self-reported pre-pregnancy body mass index ≥25 kg/m2) between 10-14 weeks of gestation and aged 18-45 years old will be enrolled.

The registry criteria, word for word

Show all 17 criteriaShow less

Who can take part

Women with overweight or obesity (self-reported pre-pregnancy body mass index ≥25 kg/m2) between 10-14 weeks of gestation and aged 18-45 years old will be enrolled
Both normotensive and hypertensive (office sitting systolic BP 140-150 mmHg and/or diastolic BP 90-100 mmHg) pregnant women will be enrolled if they are not on any antihypertensive drug treatment
We will enroll both nulliparous and multiparous women
There is no restriction regarding race/ethnicity and socioeconomic status
Women with a history of HDP will be allowed to participate
Women taking low-dose aspirin will be allowed to participate and aspirin use will be documented

Who cannot take part

Recurrent miscarriage (three or more, to avoid antiphospholipid antibody syndrome)
Evidence of cardiovascular, pulmonary, or neurological diseases
Diabetes mellitus (to avoid its effects on vascular endothelial function and sympathetic vasoconstriction)
Clinical known deep vein thrombosis, clinical symptoms and history of deep vein thrombosis, or dermatological lesions
History of drug or alcohol abuse within the last 2 years
Kidney disease (serum creatinine >0.9 mg/dL)
Current multiple pregnancies (e.g., twins, triplets, etc.)
Known major fetal chromosomal or anatomical abnormalities diagnosed during the study
Office sitting BP <100/55 mmHg or >150/100 mmHg (for safety reasons)
Current tobacco use
Pregnant women who do not have air conditioning at home during summer (for safety reasons)

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

Are you between 18 and 45 years old?

Where in United States

UT Southwestern Medical Center; Institute for Exercise and Environmental MedicineDallas, United StatesContact: Monique Roberts-Reeves, RNTaking people

About the trial

What the trial wants to find out

Obesity is a major risk factor for hypertensive disorders of pregnancy (HDP). The underlying mechanisms are largely unclear, but maternal vascular endothelial dysfunction is likely involved. Endothelial dysfunction in HDP could be attributed to 1) alterations in the L-arginine/nitric oxide (NO) pathway, and 2) an increase in endothelin-1 (ET-1). Additionally, augmented sympathetic vasoconstriction may also contribute to HDP. Chronic (repeated) whole-body heat exposure has been shown to increase NO bioavailability, decrease ET-1, and cause functional and structural adaptations in the vasculature. All these can improve vascular function, attenuate sympathetic (re)activity, lower blood pressure (BP), and reduce cardiovascular risk in non-pregnant individuals. Whether this is also true after regional (leg) heating in high-risk pregnant women is unknown. The investigators' central hypothesis is that chronic leg heating will be effective in improving vascular endothelial function and attenuating sympathetic vasoconstriction, leading to a reduction of the risk for HDP in pregnant women with obesity. The overarching goal of this proposal is to determine the vascular and neural effects of chronic leg heating in obese pregnancy. The study team plans to enroll pregnant women with obesity between 12-14 weeks of gestation and randomly assign them to either an intervention group or a control group (1:1 ratio). Participants in the intervention group will perform 16 weeks of home-based leg heating using a portable sauna blanket up to the hip (temperature of the blanket will be set at 65°C, 4 times/week, 45 min/session), whereas women in the control group will set the temperature of the blanket at 35°C at the same frequency and duration. Participants will be evaluated at baseline and then at 28-30 weeks of gestation. Aim 1 will determine the effects of chronic leg heating on maternal vascular function and surrogate markers of HDP. Aim 2 will determine the effects of chronic leg heating on sympathetic vasoconstriction and BP. Findings from this project will provide insight on the extent and potential mechanisms of how chronic leg heating works for improving vascular endothelial function and sympathetic vasoconstriction in pregnant women with obesity. Results obtained will set a foundation for future large multicenter clinical trials to determine the efficacy and generalizability of home-based leg heat therapy as a safe, ease-of-use, cost-effective, and non-drug approach for reducing the risk of HDP.

The 2 groups in the trial

Sauna blanket set at 65°CTreatment being tested
The temperature of the sauna blanket will be set at 65°C and participants will perform home-based leg heating 4 times per week, 45 minutes per session.
Treatment: Leg heating
Sauna blanket set at 35°CPlacebo, for comparison
The temperature of the sauna blanket will be set at 35°C and participants will perform home-based leg heating 4 times per week, 45 minutes per session.
Treatment: Leg heating