High-risk PregnancyNCT06932250
Leg Heating in Pregnant Women With Obesity
A study testing Leg heating in people with High-risk Pregnancy, run by University of Texas Southwestern Medical Center at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- High-risk Pregnancy
- What is being tested?
- Leg heating
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 118 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Aug 2025to 30 Apr 2030
- Phase
- Interventional
- 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 45 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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 join
- Current multiple pregnancies (e.g., twins, triplets, etc.).
- Known major fetal chromosomal or anatomical abnormalities diagnosed during the study.
- Recurrent miscarriage (three or more, to avoid antiphospholipid antibody syndrome).
- Office sitting BP <100/55 mmHg or >150/100 mmHg (for safety reasons).
- Evidence of cardiovascular, pulmonary, or neurological diseases.
- Diabetes mellitus (to avoid its effects on vascular endothelial function and sympathetic vasoconstriction).
Show all 11Show fewer
- Kidney disease (serum creatinine >0.9 mg/dL).
- 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.
- Current tobacco use.
- Pregnant women who do not have air conditioning at home during summer (for safety reasons).
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
UT Southwestern Medical Center; Institute for Exercise and Environmental Medicine
Dallas, Texas, 75231
Monique Roberts-Reeves, RN, 214-345-4656, MoniqueRoberts-Reeves@TexasHealth.org
About this study
Official title: Vascular and Neural Mechanisms of Chronic Leg Heating in Pregnant Women With Obesity
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.
Read the detailed description
Obesity is a major risk factor for hypertensive disorders of pregnancy (HDP). The underlying mechanisms are unclear, but maternal vascular endothelial dysfunction is likely involved. Endothelial dysfunction in HDP could be attributed in part to: 1) alterations in the L-arginine/nitric oxide (NO) pathway, and 2) an increase in endothelin-1 (ET-1). Conversely, augmented sympathetic vasoconstriction may also contribute to the development of HDP in women with obesity. Exercise training increases NO production, decreases ET-1, improves vascular function, attenuates sympathetic (re)activity, and reduces the risk for HDP. However, pregnant women, especially those with obesity, have poor adherence to exercise. Thus, there is an urgent need to develop novel, safe, convenient, low-cost, and well-tolerated strategies that have similar beneficial effects as exercise training. One such novel approach may be "heating".
During passive whole-body heating, body core temperature increases and cutaneous and muscle vascular resistance decreases, leading to increases in blood flow and shear stress throughout the entire arterial tree. Chronic (i.e., repeated) exposure to these temperature-dependent responses induces an increase in NO bioavailability, a decrease in ET-1, and functional and structural adaptations in the vasculature - all these can improve vascular function, attenuate sympathetic (re)activity, lower blood pressure (BP), and reduce the risk for cardiovascular morbidity and mortality. Evidence suggests that maternal body core temperature below 38.9°C is safe for the fetus.
The study team proposes to use regional (e.g., leg) rather than whole-body (e.g., hot tub or sauna) heating, since leg heating does not substantially elevate body core temperature (i.e., 37.32°C at peak in pregnant women with obesity in our pilot study), is more tolerable than whole-body heating, and can be performed in-home. Importantly, the study team's preliminary work showed that chronic home-based leg heating is safe, and can improve endothelial function, attenuate sympathetic vasoconstriction, and reduce ambulatory awake BP in pregnant women with obesity.
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.
Aim 1: Determine the effects of chronic leg heating on maternal vascular function and surrogate markers of HDP.
Hypothesis 1: Chronic leg heating will improve vascular endothelial function due to an increase in NO bioavailability and a decrease in ET-1, which may be associated with a reduction of the risk for HDP in pregnant women with obesity.
Aim 2: Determine the effects of chronic leg heating on sympathetic vasoconstriction and BP.
Hypothesis 2: Chronic leg heating will attenuate sympathetic-dependent vasoconstriction due to a decrease in sympathetic (re)activity, which may be associated with a reduction of BP in pregnant women with obesity.
Impact: 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, and its most severe form, preeclampsia.
- Conditions
- High-risk Pregnancy
- Being tested
- Leg heating
- Keywords
- Pregnancy, Obesity, Heat therapy, Vascular function, Sympathetic neural control, Blood pressure
- Medical subject headings
- Obesity, Hyperthermia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Leg heatingOther
Participants will perform home-based leg heating using a portable sauna blanket set at different temperature.
| Study group | Role | What they receive |
|---|---|---|
| Sauna blanket set at 65°C | Experimental | 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. Receives: Other: Leg heating |
| Sauna blanket set at 35°C | Placebo comparator | 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. Receives: Other: Leg heating |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in vascular endothelial function
Change in vascular endothelial function assessed by brachial artery flow-mediated vasodilation using the Doppler ultrasound technique
Measured: Baseline, 16 weeks after leg heating
Change in sympathetic neural control
Change in sympathetic neural control assessed by muscle sympathetic nerve (re)activity using the microneurographic technique
Measured: Baseline, 16 weeks after leg heating
Change in sympathetic vascular transduction
Change in sympathetic vascular transduction assessed using the microneurographic and Doppler ultrasound techniques
Measured: Baseline, 16 weeks after leg heating
Secondary outcomes (10)
Change in blood concentration of nitrate
Blood concentration of nitrate will be used to estimate nitric oxide bioavailability
Measured: Baseline, 16 weeks after leg heating
Change in blood concentration of nitrite
Blood concentration of nitrite will be used to estimate nitric oxide bioavailability
Measured: Baseline, 16 weeks after leg heating
Change in L-arginine level
Measured: Baseline, 16 weeks after leg heating
Change in asymmetric dimethylarginine level
Measured: Baseline, 16 weeks after leg heating
Change in 3-nitrotyrosine level
Measured: Baseline, 16 weeks after leg heating
Change in concentration of endothelin-1
Measured: Baseline, 16 weeks after leg heating
Change in 24-hour ambulatory blood pressure
Measured: Baseline, 16 weeks after leg heating
Change in placental growth factor level
Measured: Baseline, 16 weeks after leg heating
Change in solube fms-like tyrosine kinase-1 level
Measured: Baseline, 16 weeks after leg heating
Change in soluble endoglin level
Measured: Baseline, 16 weeks after leg heating
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Apr 2025
- Study start1 Aug 2025
- Primary completion31 Jan 2030 (estimated)
- Study completion30 Apr 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (40)Papers the sponsor has linked to this study.
- Other trials for High-risk PregnancyStudies of the same condition, open and under way.
- More trials run by University of Texas Southwestern Medical CenterThe 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
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 118 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Texas Southwestern Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Qi Fu, University of Texas Southwestern Medical Center
- Investigators
- Qi Fu, MD, PhD, Principal investigator, UT Southwestern Medical Center; Institute for Exercise and Environmental Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06932250
- Sponsor's protocol ID
- STU20250500
- Status last verified
- Apr 2026
- First submitted
- 19 Mar 2025
- Last updated
- 17 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Only deidentified individual participant data will be available to other researchers.
Publications
Lisonkova S, Joseph KS. Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease. Am J Obstet Gynecol. 2013 Dec;209(6):544.e1-544.e12. doi: 10.1016/j.ajog.2013.08.019. Epub 2013 Aug 22.
PubMed 23973398Ford ND, Cox S, Ko JY, Ouyang L, Romero L, Colarusso T, Ferre CD, Kroelinger CD, Hayes DK, Barfield WD. Hypertensive Disorders in Pregnancy and Mortality at Delivery Hospitalization - United States, 2017-2019. MMWR Morb Mortal Wkly Rep. 2022 Apr 29;71(17):585-591. doi: 10.15585/mmwr.mm7117a1.
PubMed 35482575Bicocca MJ, Mendez-Figueroa H, Chauhan SP, Sibai BM. Maternal Obesity and the Risk of Early-Onset and Late-Onset Hypertensive Disorders of Pregnancy. Obstet Gynecol. 2020 Jul;136(1):118-127. doi: 10.1097/AOG.0000000000003901.
PubMed 32541276Wang MC, Freaney PM, Perak AM, Greenland P, Lloyd-Jones DM, Grobman WA, Khan SS. Trends in Prepregnancy Obesity and Association With Adverse Pregnancy Outcomes in the United States, 2013 to 2018. J Am Heart Assoc. 2021 Sep 7;10(17):e020717. doi: 10.1161/JAHA.120.020717. Epub 2021 Aug 25.
PubMed 34431359Aksin S, Andan C, Tunc S, Goklu MR. Comparison of brachial artery flow-mediated dilatation, uterine artery Doppler, and umbilical artery Doppler measurements in obese and normal pregnant women. J Obstet Gynaecol Res. 2022 Feb;48(2):340-350. doi: 10.1111/jog.15092. Epub 2021 Nov 2.
PubMed 34729866Stewart FM, Freeman DJ, Ramsay JE, Greer IA, Caslake M, Ferrell WR. Longitudinal assessment of maternal endothelial function and markers of inflammation and placental function throughout pregnancy in lean and obese mothers. J Clin Endocrinol Metab. 2007 Mar;92(3):969-75. doi: 10.1210/jc.2006-2083. Epub 2006 Dec 27.
PubMed 17192290Petrella E, Pignatti L, Neri I, Facchinetti F. The l-arginine/nitric oxide pathway is impaired in overweight/obese pregnant women. Pregnancy Hypertens. 2014 Apr;4(2):150-5. doi: 10.1016/j.preghy.2014.01.001. Epub 2014 Feb 3.
PubMed 26104420Chin-Dusting JP, Willems L, Kaye DM. L-arginine transporters in cardiovascular disease: a novel therapeutic target. Pharmacol Ther. 2007 Dec;116(3):428-36. doi: 10.1016/j.pharmthera.2007.08.001. Epub 2007 Aug 28.
PubMed 17915331Schiffrin EL, Touyz RM. Vascular biology of endothelin. J Cardiovasc Pharmacol. 1998;32 Suppl 3:S2-13.
PubMed 9883741Schobel HP, Fischer T, Heuszer K, Geiger H, Schmieder RE. Preeclampsia -- a state of sympathetic overactivity. N Engl J Med. 1996 Nov 14;335(20):1480-5. doi: 10.1056/NEJM199611143352002.
PubMed 8890098Greenwood JP, Scott EM, Stoker JB, Walker JJ, Mary DA. Sympathetic neural mechanisms in normal and hypertensive pregnancy in humans. Circulation. 2001 Oct 30;104(18):2200-4. doi: 10.1161/hc4301.098253.
PubMed 11684631Greenwood JP, Scott EM, Walker JJ, Stoker JB, Mary DA. The magnitude of sympathetic hyperactivity in pregnancy-induced hypertension and preeclampsia. Am J Hypertens. 2003 Mar;16(3):194-9. doi: 10.1016/s0895-7061(02)03256-9.
PubMed 12620697Greenwood JP, Stoker JB, Walker JJ, Mary DA. Sympathetic nerve discharge in normal pregnancy and pregnancy-induced hypertension. J Hypertens. 1998 May;16(5):617-24. doi: 10.1097/00004872-199816050-00009.
PubMed 9797173Hissen SL, Takeda R, Badrov MB, Arias-Franklin S, Patel S, Nelson DB, Babb TG, Fu Q. Impact of maternal obesity on resting muscle sympathetic nerve activity during uncomplicated pregnancy: a longitudinal assessment. Am J Physiol Regul Integr Comp Physiol. 2024 Jan 1;326(1):R10-R18. doi: 10.1152/ajpregu.00098.2023. Epub 2023 Nov 13.
PubMed 37955129Dyakova EY, Kapilevich LV, Shylko VG, Popov SV, Anfinogenova Y. Physical exercise associated with NO production: signaling pathways and significance in health and disease. Front Cell Dev Biol. 2015 Apr 2;3:19. doi: 10.3389/fcell.2015.00019. eCollection 2015.
PubMed 25883934
Study at a glance
From the registry record, last updated by the sponsor on 17 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vascular and Neural Mechanisms of Chronic Leg Heating in Pregnant Women With Obesity
- ClinicalTrials.gov ID
- NCT06932250
- Acronym / sponsor ID
- STU20250500
- Conditions
- High-risk Pregnancy
- Keywords
- Pregnancy, Obesity, Heat therapy, Vascular function, Sympathetic neural control, Blood pressure
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 118 participants (estimated)
- Lead sponsor
- University of Texas Southwestern Medical CenterUniversity, hospital or other
- Study start
- 1 Aug 2025 (actual)
- Primary completion
- 31 Jan 2030 (estimated)
- Study completion
- 30 Apr 2030 (estimated)
- First posted
- 17 Apr 2025 (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.
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.
Detailed description
Obesity is a major risk factor for hypertensive disorders of pregnancy (HDP). The underlying mechanisms are unclear, but maternal vascular endothelial dysfunction is likely involved. Endothelial dysfunction in HDP could be attributed in part to: 1) alterations in the L-arginine/nitric oxide (NO) pathway, and 2) an increase in endothelin-1 (ET-1). Conversely, augmented sympathetic vasoconstriction may also contribute to the development of HDP in women with obesity. Exercise training increases NO production, decreases ET-1, improves vascular function, attenuates sympathetic (re)activity, and reduces the risk for HDP. However, pregnant women, especially those with obesity, have poor adherence to exercise. Thus, there is an urgent need to develop novel, safe, convenient, low-cost, and well-tolerated strategies that have similar beneficial effects as exercise training. One such novel approach may be "heating".
During passive whole-body heating, body core temperature increases and cutaneous and muscle vascular resistance decreases, leading to increases in blood flow and shear stress throughout the entire arterial tree. Chronic (i.e., repeated) exposure to these temperature-dependent responses induces an increase in NO bioavailability, a decrease in ET-1, and functional and structural adaptations in the vasculature - all these can improve vascular function, attenuate sympathetic (re)activity, lower blood pressure (BP), and reduce the risk for cardiovascular morbidity and mortality. Evidence suggests that maternal body core temperature below 38.9°C is safe for the fetus.
The study team proposes to use regional (e.g., leg) rather than whole-body (e.g., hot tub or sauna) heating, since leg heating does not substantially elevate body core temperature (i.e., 37.32°C at peak in pregnant women with obesity in our pilot study), is more tolerable than whole-body heating, and can be performed in-home. Importantly, the study team's preliminary work showed that chronic home-based leg heating is safe, and can improve endothelial function, attenuate sympathetic vasoconstriction, and reduce ambulatory awake BP in pregnant women with obesity.
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.
Aim 1: Determine the effects of chronic leg heating on maternal vascular function and surrogate markers of HDP.
Hypothesis 1: Chronic leg heating will improve vascular endothelial function due to an increase in NO bioavailability and a decrease in ET-1, which may be associated with a reduction of the risk for HDP in pregnant women with obesity.
Aim 2: Determine the effects of chronic leg heating on sympathetic vasoconstriction and BP.
Hypothesis 2: Chronic leg heating will attenuate sympathetic-dependent vasoconstriction due to a decrease in sympathetic (re)activity, which may be associated with a reduction of BP in pregnant women with obesity.
Impact: 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, and its most severe form, preeclampsia.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sauna blanket set at 65°C | Experimental | Other: Leg heatingThe 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. |
| Sauna blanket set at 35°C | Placebo comparator | Other: Leg heatingThe 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. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (11 listed)
- Current multiple pregnancies (e.g., twins, triplets, etc.).
- Known major fetal chromosomal or anatomical abnormalities diagnosed during the study.
- Recurrent miscarriage (three or more, to avoid antiphospholipid antibody syndrome).
- Office sitting BP <100/55 mmHg or >150/100 mmHg (for safety reasons).
- Evidence of cardiovascular, pulmonary, or neurological diseases.
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 |
|---|---|---|
| Leg heatingParticipants will perform home-based leg heating using a portable sauna blanket set at different temperature. | Other | Sauna blanket set at 35°C, Sauna blanket set at 65°C |
Primary outcome
Change in vascular endothelial function
Time frame: Baseline, 16 weeks after leg heating
Change in vascular endothelial function assessed by brachial artery flow-mediated vasodilation using the Doppler ultrasound technique
Change in sympathetic neural control
Time frame: Baseline, 16 weeks after leg heating
Change in sympathetic neural control assessed by muscle sympathetic nerve (re)activity using the microneurographic technique
Change in sympathetic vascular transduction
Time frame: Baseline, 16 weeks after leg heating
Change in sympathetic vascular transduction assessed using the microneurographic and Doppler ultrasound techniques
10 secondary outcomes
Change in blood concentration of nitrate
Time frame: Baseline, 16 weeks after leg heating
Change in blood concentration of nitrite
Time frame: Baseline, 16 weeks after leg heating
Change in L-arginine level
Time frame: Baseline, 16 weeks after leg heating
Change in asymmetric dimethylarginine level
Time frame: Baseline, 16 weeks after leg heating
Change in 3-nitrotyrosine level
Time frame: Baseline, 16 weeks after leg heating
Change in concentration of endothelin-1
Time frame: Baseline, 16 weeks after leg heating
Change in 24-hour ambulatory blood pressure
Time frame: Baseline, 16 weeks after leg heating
Change in placental growth factor level
Time frame: Baseline, 16 weeks after leg heating
Change in solube fms-like tyrosine kinase-1 level
Time frame: Baseline, 16 weeks after leg heating
Change in soluble endoglin level
Time frame: Baseline, 16 weeks after leg heating
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 17 Apr 2026.
- Background: PubMed 23973398Lisonkova S, Joseph KS. Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease. Am J Obstet Gynecol. 2013 Dec;209(6):544.e1-544.e12. doi: 10.1016/j.ajog.2013.08.019. Epub 2013 Aug 22.
- Background: PubMed 35482575Ford ND, Cox S, Ko JY, Ouyang L, Romero L, Colarusso T, Ferre CD, Kroelinger CD, Hayes DK, Barfield WD. Hypertensive Disorders in Pregnancy and Mortality at Delivery Hospitalization - United States, 2017-2019. MMWR Morb Mortal Wkly Rep. 2022 Apr 29;71(17):585-591. doi: 10.15585/mmwr.mm7117a1.
- Background: PubMed 32541276Bicocca MJ, Mendez-Figueroa H, Chauhan SP, Sibai BM. Maternal Obesity and the Risk of Early-Onset and Late-Onset Hypertensive Disorders of Pregnancy. Obstet Gynecol. 2020 Jul;136(1):118-127. doi: 10.1097/AOG.0000000000003901.
- Background: PubMed 34431359Wang MC, Freaney PM, Perak AM, Greenland P, Lloyd-Jones DM, Grobman WA, Khan SS. Trends in Prepregnancy Obesity and Association With Adverse Pregnancy Outcomes in the United States, 2013 to 2018. J Am Heart Assoc. 2021 Sep 7;10(17):e020717. doi: 10.1161/JAHA.120.020717. Epub 2021 Aug 25.
- Background: PubMed 34729866Aksin S, Andan C, Tunc S, Goklu MR. Comparison of brachial artery flow-mediated dilatation, uterine artery Doppler, and umbilical artery Doppler measurements in obese and normal pregnant women. J Obstet Gynaecol Res. 2022 Feb;48(2):340-350. doi: 10.1111/jog.15092. Epub 2021 Nov 2.
- Background: PubMed 17192290Stewart FM, Freeman DJ, Ramsay JE, Greer IA, Caslake M, Ferrell WR. Longitudinal assessment of maternal endothelial function and markers of inflammation and placental function throughout pregnancy in lean and obese mothers. J Clin Endocrinol Metab. 2007 Mar;92(3):969-75. doi: 10.1210/jc.2006-2083. Epub 2006 Dec 27.
- Background: PubMed 26104420Petrella E, Pignatti L, Neri I, Facchinetti F. The l-arginine/nitric oxide pathway is impaired in overweight/obese pregnant women. Pregnancy Hypertens. 2014 Apr;4(2):150-5. doi: 10.1016/j.preghy.2014.01.001. Epub 2014 Feb 3.
- Background: PubMed 17915331Chin-Dusting JP, Willems L, Kaye DM. L-arginine transporters in cardiovascular disease: a novel therapeutic target. Pharmacol Ther. 2007 Dec;116(3):428-36. doi: 10.1016/j.pharmthera.2007.08.001. Epub 2007 Aug 28.
- Background: PubMed 9883741Schiffrin EL, Touyz RM. Vascular biology of endothelin. J Cardiovasc Pharmacol. 1998;32 Suppl 3:S2-13.
- Background: PubMed 8890098Schobel HP, Fischer T, Heuszer K, Geiger H, Schmieder RE. Preeclampsia -- a state of sympathetic overactivity. N Engl J Med. 1996 Nov 14;335(20):1480-5. doi: 10.1056/NEJM199611143352002.
- Background: PubMed 11684631Greenwood JP, Scott EM, Stoker JB, Walker JJ, Mary DA. Sympathetic neural mechanisms in normal and hypertensive pregnancy in humans. Circulation. 2001 Oct 30;104(18):2200-4. doi: 10.1161/hc4301.098253.
- Background: PubMed 12620697Greenwood JP, Scott EM, Walker JJ, Stoker JB, Mary DA. The magnitude of sympathetic hyperactivity in pregnancy-induced hypertension and preeclampsia. Am J Hypertens. 2003 Mar;16(3):194-9. doi: 10.1016/s0895-7061(02)03256-9.
- Individual participant dataSharing planned: Yes. Only deidentified individual participant data will be available to other researchers.
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Pucotenlimab, Lenvatinib, and SBRT Before Surgery for Localized Clear Cell Renal Cell Carcinoma
Localized Clear Cell Renal Cell Carcinoma
Recruiting
Unravelling Tumour Biology In Ovarian Cancer With Precision Imaging
High Grade Serous Ovarian Cancer
RecruitingPhase 2
Immunotherapy Platform Study in Platinum Resistant High Grade Serous Ovarian Cancer
Ovarian Cancer
RecruitingPhase 3
Tranexamic Acid to Prevent Heavy Bleeding After Childbirth in Women at Higher Risk
Postpartum Hemorrhage
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.
Qi Fu, MD, PhD principal investigator
UT Southwestern Medical Center; Institute for Exercise and Environmental Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Leg heating in people with High-risk Pregnancy, run by University of Texas Southwestern Medical Center 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 6 inclusion and 11 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 17 Apr 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.
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 Qi Fu, MD, PhD (214-345-8125, QiFu@TexasHealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in vascular endothelial function (time frame: Baseline, 16 weeks after leg heating). The study lists 3 primary outcomes in all. 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 NCT06932250, which also lists 40 linked publications.
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 17 Apr 2026.