Thermally Neutral Condition With Light-intensity WorkGaHPSNCT07326176
Evaluating Pathophysiological Mechanisms of Acute and Chronic Heat Stress on Maternal and Fetal Health
A study testing Heat and Physical Work Exposure Protocol in people with Thermally Neutral Condition With Light-intensity Work and Thermally Neutral Condition With Moderate-intensity Work, run by University of Thessaly at 1 site in Greece.
Trial summary
This study examined the effects of environmental heat and physical work on maternal thermoregulation and fetal physiology in late pregnancy. Twenty-four healthy pregnant women at 28-32 weeks of gestation completed four randomized and counterbalanced 3-hour experimental scenarios combining two thermal conditions… Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Thermally Neutral Condition With Light-intensity Work, Thermally Neutral Condition With Moderate-intensity Work, Warm Condition With Light-intensity Work
- What is being tested?
- Heat and Physical Work Exposure Protocol
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteGreece
- Study dates
- 15 May 2024to 15 Aug 2024
- Phase
- Interventional
- 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 18 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy pregnant women between 28 and 32 weeks of gestation
- Singleton pregnancy
- Habitually heat-acclimatized, defined as daily exposure to outdoor environmental conditions equal to or warmer than those used in the study
- Able to perform treadmill walking at light and moderate intensities
- Willing and able to attend all laboratory sessions
- Provided written informed consent
- Age 18 years or older
Who cannot join
- Multiple pregnancy (e.g., twins, triplets)
- Chronic medical conditions, including but not limited to:
- Hypertension
- Diabetes
- HIV
- Obstetric complications, including:
Show all 12Show fewer
- Pre-eclampsia
- Severe anemia
- Acute infections, including urinary tract infection
- Any contraindication to exercise based on the Physical Activity Readiness for Pregnancy (PARmed-X for Pregnancy) checklist
- Inability to comply with the study procedures or scheduled visits
- Any condition deemed by investigators to compromise participant safety or data integrity
Trial locations and contacts
1 site in 1 country.
Greece1 site
Dept. of Physical Education and Sport Science, University of Thessaly
Trikala, Thessaly, 42100
About this study
This study examined the effects of environmental heat and physical work on maternal thermoregulation and fetal physiology in late pregnancy. Twenty-four healthy pregnant women at 28-32 weeks of gestation completed four randomized and counterbalanced 3-hour experimental scenarios combining two thermal conditions (temperate 20 °C and warm 30 °C, both at 45% relative humidity, shaded) and two physical workload intensities (light and moderate treadmill walking). Each scenario included 1 hour of passive seated exposure, 1 hour of treadmill walking, and 1 hour of seated recovery. Maternal thermoregulatory, cardiovascular, perceptual, and hydration responses were monitored continuously, while fetal heart rate and Doppler-derived indices of uterine, umbilical, and middle cerebral artery blood flow were assessed at baseline, end of passive exposure, end of work, and end of recovery. The aims of the study were: (1) to characterize maternal physiological and perceptual responses to heat exposure and physical work; (2) to determine whether maternal physiological heat strain directly affects fetal cardiovascular strain and maternal-fetal hemodynamics; and (3) to examine whether maternal characteristics, particularly body mass index and age, influence maternal thermoregulatory responses and fetal susceptibility to heat stress.
- Conditions
- Thermally Neutral Condition With Light-intensity Work, Thermally Neutral Condition With Moderate-intensity Work, Warm Condition With Light-intensity Work, Warm Condition With Moderate-intensity Work
- Being tested
- Heat and Physical Work Exposure Protocol
- Keywords
- heat stress, heat strain
- Medical subject headings
- Heat Stress Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heat and Physical Work Exposure ProtocolOther
A controlled 3-hour environmental chamber protocol consisting of 1 hour of passive seated exposure, 1 hour of treadmill walking at prescribed light or moderate intensities (alternating between 2-3 METs or 3-4 METs every 10 minutes), and 1 hour of seated recovery. Each session was conducted under either temperate (20 °C, 45% relative humidity, shaded) or warm (30 °C, 45% relative humidity, shaded) environmental conditions. Environmental settings, workload intensity, and timing were standardized across all participants.
| Study group | Role | What they receive |
|---|---|---|
| Temperate-Light | Other | Participants were exposed to a temperate environment (20 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of light-intensity treadmill walking (alternating between 2 and 3 METs [Metabolic Equivalents] every 10 minutes), and 1 hour seated recovery. Receives: Other: Heat and Physical Work Exposure Protocol |
| Temperate-Moderate | Other | Participants were exposed to a temperate environment (20 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of moderate-intensity treadmill walking (alternating between 3 and 4 METs every 10 minutes), and 1 hour seated recovery. Receives: Other: Heat and Physical Work Exposure Protocol |
| Warm-Light | Other | Participants were exposed to a warm environment (30 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of light-intensity treadmill walking (alternating between 2 and 3 METs every 10 minutes), and 1 hour seated recovery. Receives: Other: Heat and Physical Work Exposure Protocol |
| Warm-Moderate | Other | Participants were exposed to a warm environment (30 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of moderate-intensity treadmill walking (alternating between 3 and 4 METs every 10 minutes), and 1 hour seated recovery. Receives: Other: Heat and Physical Work Exposure Protocol |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maternal Core Body Temperature
Core body temperature continuously assessed using an ingestible telemetric temperature capsule to quantify maternal thermoregulatory responses to different combinations of environmental heat (20 °C vs 30 °C) and physical workload (light vs moderate).
Measured: Continuously recorded throughout each 3-hour experimental session (baseline, 1-hour passive exposure, 1-hour physical work, and 1-hour recovery).
Maternal Physiological Strain Index
Physiological Strain Index (0-10 scale) calculated from core body temperature and heart rate to quantify overall maternal physiological heat strain under different environmental and workload combinations.
Measured: Continuously calculated throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Fetal Heart Rate
Fetal heart rate assessed using obstetric ultrasound to evaluate fetal cardiovascular responses to maternal exposure to different environmental temperatures and physical workload intensities.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Uterine Artery Pulsatility Index (PI)
Pulsatility Index of the left and right uterine arteries measured by Doppler ultrasound to assess uteroplacental vascular resistance under different environmental and workload conditions.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Uterine Artery Resistive Index (RI)
Resistive Index of the left and right uterine arteries measured by Doppler ultrasound to assess uteroplacental vascular resistance under different environmental and workload conditions.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Umbilical Artery Pulsatility Index
Pulsatility Index of the umbilical artery measured by Doppler ultrasound to evaluate fetoplacental blood flow in response to maternal heat exposure and physical work.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Umbilical Artery Resistive Index
Resistive Index of the umbilical artery measured by Doppler ultrasound to evaluate fetoplacental blood flow in response to maternal heat exposure and physical work.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Middle Cerebral Artery Pulsatility Index
Pulsatility Index of the fetal middle cerebral artery measured by Doppler ultrasound to assess fetal cerebral vascular responses to maternal heat strain.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Middle Cerebral Artery Resistive Index
Resistive Index of the fetal middle cerebral artery measured by Doppler ultrasound to assess fetal cerebral vascular responses to maternal heat strain.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Composite Maternal-Fetal Hemodynamic Ratios (cerebroplacental ratio)
Cerebroplacental ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Composite Maternal-Fetal Hemodynamic Ratios (cerebrouterine PI ratio)
Cerebrouterine PI ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Composite Maternal-Fetal Hemodynamic Ratios (Uteroplacental:cerebral PI ratio)
Uteroplacental:cerebral PI ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
Measured: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Secondary outcomes (8)
Maternal Skin Temperature
Skin temperature measured at four body sites (chest, upper arm, thigh, lower leg) using iButton sensors and expressed as a weighted mean skin temperature to characterize peripheral thermal responses to environmental heat and physical work.
Measured: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Heart Rate
Maternal heart rate measured using a chest-strap heart rate monitor to assess cardiovascular strain across different environmental (20 °C vs 30 °C) and workload (light vs moderate) conditions.
Measured: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Local Sweat Rate
Local sweat rate measured over the trapezius muscle using a ventilated capsule technique, adjusted for skin area, to quantify sweating responses to environmental heat and physical work.
Measured: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Skin Blood Flow
Skin blood flow assessed using laser Doppler flowmetry at the finger and forearm to characterize peripheral vasodilation in response to environmental heat exposure and physical work.
Measured: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Arterial Blood Pressure
Systolic, diastolic, and mean arterial blood pressure measured intermittently using a standard automated sphygmomanometer to evaluate cardiovascular responses to environmental heat and physical work.
Measured: Measured at baseline and every 30 minutes during each 3-hour experimental session.
Thermal Sensation
Thermal sensation assessed using a 9-point scale ranging from -4 (extremely cold) to +4 (extremely hot) to quantify participants' perceived body temperature during exposure to different environmental heat and physical workload conditions.
Measured: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
Thermal Comfort
Thermal comfort assessed using a 10-point scale ranging from 1 (comfortable) to 10 (extremely uncomfortable) to evaluate subjective comfort during environmental heat exposure and physical work.
Measured: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
Rating of Perceived Exertion (RPE)
Perceived exertion assessed using the Borg 6-20 scale to quantify subjective physical effort during treadmill walking under different environmental and workload conditions.
Measured: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2026
- Study start15 May 2024
- Primary completion15 Aug 2024
- Study completion15 Aug 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Thermally Neutral Condition With Light-intensity WorkStudies of the same condition, open and under way.
- More trials run by University of ThessalyThe 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Thessaly
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Leonidas G. Ioannou, University of Thessaly
- Investigators
- Leonidas Ioannou, PhD, Principal investigator, University of Thessaly
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07326176
- Sponsor's protocol ID
- GaHPS
- Other IDs
- 227176/Z/23/Z
- Acronym
- GaHPS
- Status last verified
- Dec 2025
- First submitted
- 10 Dec 2025
- Last updated
- 8 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared due to the sensitive nature of the data collected from pregnant women and their fetuses and the potential risk of re-identification. De-identified, non-trackable aggregated data supporting the main study findings will be made available after publication.
Publications
Bonell A, Sonko B, Badjie J, Samateh T, Saidy T, Sosseh F, Sallah Y, Bajo K, Murray KA, Hirst J, Vicedo-Cabrera A, Prentice AM, Maxwell NS, Haines A. Environmental heat stress on maternal physiology and fetal blood flow in pregnant subsistence farmers in The Gambia, west Africa: an observational cohort study. Lancet Planet Health. 2022 Dec;6(12):e968-e976. doi: 10.1016/S2542-5196(22)00242-X.
PubMed 36495891Bonell A, G Ioannou L, Sesay A, A Murray K, Bah B, Jeffries D, E Moore S, Vicero-Cabrera A, S Maxwell N, E Hirst J, Tan C, Saucy A, Watters D, Sonko B, Okoh E, Idris Y, Oluwatosin Adefila W, Manneh J, Leigh-Nabou M, Bojang S, Flouris A, Haines A, Prentice A, N Sferruzzi-Perri A. Study protocol for an observational cohort study of heat stress impacts in pregnancy in The Gambia, West Africa. Wellcome Open Res. 2025 Feb 7;9:624. doi: 10.12688/wellcomeopenres.23172.2. eCollection 2024.
PubMed 39925648
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluating Pathophysiological Mechanisms of Acute and Chronic Heat Stress on Maternal and Fetal Health
- ClinicalTrials.gov ID
- NCT07326176
- Acronym / sponsor ID
- GaHPS / GaHPS
- Conditions
- Thermally Neutral Condition With Light-intensity Work, Thermally Neutral Condition With Moderate-intensity Work, Warm Condition With Light-intensity Work, Warm Condition With Moderate-intensity Work
- Keywords
- heat stress, heat strain
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- University of ThessalyUniversity, hospital or other
- Study start
- 15 May 2024 (actual)
- Primary completion
- 15 Aug 2024 (actual)
- Study completion
- 15 Aug 2024 (actual)
- First posted
- 8 Jan 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 study examined the effects of environmental heat and physical work on maternal thermoregulation and fetal physiology in late pregnancy. Twenty-four healthy pregnant women at 28-32 weeks of gestation completed four randomized and counterbalanced 3-hour experimental scenarios combining two thermal conditions (temperate 20 °C and warm 30 °C, both at 45% relative humidity, shaded) and two physical workload intensities (light and moderate treadmill walking). Each scenario included 1 hour of passive seated exposure, 1 hour of treadmill walking, and 1 hour of seated recovery. Maternal thermoregulatory, cardiovascular, perceptual, and hydration responses were monitored continuously, while fetal heart rate and Doppler-derived indices of uterine, umbilical, and middle cerebral artery blood flow were assessed at baseline, end of passive exposure, end of work, and end of recovery. The aims of the study were: (1) to characterize maternal physiological and perceptual responses to heat exposure and physical work; (2) to determine whether maternal physiological heat strain directly affects fetal cardiovascular strain and maternal-fetal hemodynamics; and (3) to examine whether maternal characteristics, particularly body mass index and age, influence maternal thermoregulatory responses and fetal susceptibility to heat stress.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Temperate-Light | Other | Other: Heat and Physical Work Exposure ProtocolParticipants were exposed to a temperate environment (20 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of light-intensity treadmill walking (alternating between 2 and 3 METs [Metabolic Equivalents] every 10 minutes), and 1 hour seated recovery. |
| Temperate-Moderate | Other | Other: Heat and Physical Work Exposure ProtocolParticipants were exposed to a temperate environment (20 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of moderate-intensity treadmill walking (alternating between 3 and 4 METs every 10 minutes), and 1 hour seated recovery. |
| Warm-Light | Other | Other: Heat and Physical Work Exposure ProtocolParticipants were exposed to a warm environment (30 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of light-intensity treadmill walking (alternating between 2 and 3 METs every 10 minutes), and 1 hour seated recovery. |
| Warm-Moderate | Other | Other: Heat and Physical Work Exposure ProtocolParticipants were exposed to a warm environment (30 °C, 45% relative humidity, shaded) for a 3-hour protocol consisting of 1 hour passive seated exposure, 1 hour of moderate-intensity treadmill walking (alternating between 3 and 4 METs every 10 minutes), and 1 hour seated recovery. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Healthy pregnant women between 28 and 32 weeks of gestation
- Singleton pregnancy
- Habitually heat-acclimatized, defined as daily exposure to outdoor environmental conditions equal to or warmer than those used in the study
- Able to perform treadmill walking at light and moderate intensities
- Willing and able to attend all laboratory sessions
Key exclusion criteria (12 listed)
- Multiple pregnancy (e.g., twins, triplets)
- Chronic medical conditions, including but not limited to:
- Obstetric complications, including:
- Acute infections, including urinary tract infection
- Any contraindication to exercise based on the Physical Activity Readiness for Pregnancy (PARmed-X for Pregnancy) checklist
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 |
|---|---|---|
| Heat and Physical Work Exposure ProtocolA controlled 3-hour environmental chamber protocol consisting of 1 hour of passive seated exposure, 1 hour of treadmill walking at prescribed light or moderate intensities (alternating between 2-3 METs or 3-4 METs every 10 minutes), and 1 hour of seated recovery. Each session was conducted under either temperate (20 °C, 45% relative humidity, shaded) or warm (30 °C, 45% relative humidity, shaded) environmental conditions. Environmental settings, workload intensity, and timing were standardized across all participants. | Other | Temperate-Light, Temperate-Moderate, Warm-Light, Warm-Moderate |
Primary outcome
Maternal Core Body Temperature
Time frame: Continuously recorded throughout each 3-hour experimental session (baseline, 1-hour passive exposure, 1-hour physical work, and 1-hour recovery).
Core body temperature continuously assessed using an ingestible telemetric temperature capsule to quantify maternal thermoregulatory responses to different combinations of environmental heat (20 °C vs 30 °C) and physical workload (light vs moderate).
Maternal Physiological Strain Index
Time frame: Continuously calculated throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Physiological Strain Index (0-10 scale) calculated from core body temperature and heart rate to quantify overall maternal physiological heat strain under different environmental and workload combinations.
Fetal Heart Rate
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Fetal heart rate assessed using obstetric ultrasound to evaluate fetal cardiovascular responses to maternal exposure to different environmental temperatures and physical workload intensities.
Uterine Artery Pulsatility Index (PI)
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Pulsatility Index of the left and right uterine arteries measured by Doppler ultrasound to assess uteroplacental vascular resistance under different environmental and workload conditions.
Uterine Artery Resistive Index (RI)
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Resistive Index of the left and right uterine arteries measured by Doppler ultrasound to assess uteroplacental vascular resistance under different environmental and workload conditions.
Umbilical Artery Pulsatility Index
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Pulsatility Index of the umbilical artery measured by Doppler ultrasound to evaluate fetoplacental blood flow in response to maternal heat exposure and physical work.
Umbilical Artery Resistive Index
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Resistive Index of the umbilical artery measured by Doppler ultrasound to evaluate fetoplacental blood flow in response to maternal heat exposure and physical work.
Middle Cerebral Artery Pulsatility Index
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Pulsatility Index of the fetal middle cerebral artery measured by Doppler ultrasound to assess fetal cerebral vascular responses to maternal heat strain.
Middle Cerebral Artery Resistive Index
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Resistive Index of the fetal middle cerebral artery measured by Doppler ultrasound to assess fetal cerebral vascular responses to maternal heat strain.
Composite Maternal-Fetal Hemodynamic Ratios (cerebroplacental ratio)
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Cerebroplacental ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
Composite Maternal-Fetal Hemodynamic Ratios (cerebrouterine PI ratio)
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Cerebrouterine PI ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
Composite Maternal-Fetal Hemodynamic Ratios (Uteroplacental:cerebral PI ratio)
Time frame: Each 3-hour session: 0 min (baseline), 60 min (end of passive exposure), 120 min (end of physical work), 180 min (end of recovery).
Uteroplacental:cerebral PI ratio calculated using artery Doppler measurements to characterize maternal-fetal hemodynamics and fetal strain under different environmental and workload conditions.
8 secondary outcomes
Maternal Skin Temperature
Time frame: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Heart Rate
Time frame: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Local Sweat Rate
Time frame: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Skin Blood Flow
Time frame: Continuously recorded throughout each 3-hour experimental session (baseline, passive exposure, physical work, and recovery).
Maternal Arterial Blood Pressure
Time frame: Measured at baseline and every 30 minutes during each 3-hour experimental session.
Thermal Sensation
Time frame: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
Thermal Comfort
Time frame: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
Rating of Perceived Exertion (RPE)
Time frame: Measured at baseline and every 30 minutes throughout each 3-hour experimental session (passive exposure, physical work, and recovery).
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 8 Jan 2026.
- Background: PubMed 36495891Bonell A, Sonko B, Badjie J, Samateh T, Saidy T, Sosseh F, Sallah Y, Bajo K, Murray KA, Hirst J, Vicedo-Cabrera A, Prentice AM, Maxwell NS, Haines A. Environmental heat stress on maternal physiology and fetal blood flow in pregnant subsistence farmers in The Gambia, west Africa: an observational cohort study. Lancet Planet Health. 2022 Dec;6(12):e968-e976. doi: 10.1016/S2542-5196(22)00242-X.
- Background: PubMed 39925648Bonell A, G Ioannou L, Sesay A, A Murray K, Bah B, Jeffries D, E Moore S, Vicero-Cabrera A, S Maxwell N, E Hirst J, Tan C, Saucy A, Watters D, Sonko B, Okoh E, Idris Y, Oluwatosin Adefila W, Manneh J, Leigh-Nabou M, Bojang S, Flouris A, Haines A, Prentice A, N Sferruzzi-Perri A. Study protocol for an observational cohort study of heat stress impacts in pregnancy in The Gambia, West Africa. Wellcome Open Res. 2025 Feb 7;9:624. doi: 10.12688/wellcomeopenres.23172.2. eCollection 2024.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared due to the sensitive nature of the data collected from pregnant women and their fetuses and the potential risk of re-identification. De-identified, non-trackable aggregated data supporting the main study findings will be made available after publication.
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.
Leonidas Ioannou, PhD principal investigator
University of Thessaly
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heat and Physical Work Exposure Protocol in people with Thermally Neutral Condition With Light-intensity Work and Thermally Neutral Condition With Moderate-intensity Work, run by University of Thessaly at 1 site in Greece.
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 7 inclusion and 12 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: finished, as of the sponsor's last update on 8 Jan 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 Greece. 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?
Maternal Core Body Temperature (time frame: Continuously recorded throughout each 3-hour experimental session (baseline, 1-hour passive exposure, 1-hour physical work, and 1-hour recovery).). The study lists 12 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 NCT07326176, which also lists 2 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 8 Jan 2026.