Hypertensive Disorder of PregnancyNCT07312227
A Prospective Longitudinal Observational Cohort Study of Pregnant Women Residing at High Altitude in Bolivia
An observational study of Hypertensive Disorder of Pregnancy and Pulmonary Arterial Hypertension, run by Massachusetts General Hospital at 2 sites in 2 countries.
Trial summary
In this study, the investigators will follow two small cohorts of pregnant women: a cohort of healthy women with uncomplicated pregnancies residing at high altitude, a control group of healthy women with uncomplicated pregnancies residing at sea level, to characterize differences in cardiopulmonary adaptation and… 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
- Hypertensive Disorder of Pregnancy, Pulmonary Arterial Hypertension, Intrauterine Growth Restriction
- How many people
- 27 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 11 Feb 2026to Feb 2027
- Phase
- Observational
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
Study population: The cohort of healthy pregnant women residing at high altitude will selected from pregnant women who have lived at an altitude greater than 3500 meters throughout pregnancy and at delivery. The control group will be pregnant women who have lived at sea level throughout pregnancy and at delivery.
Who may be able to join
- women delivering at participating hospitals at more than 3500 meters or women delivering at participating hospitals at sea level
- signed informed consent
Who cannot join
- preexisting cardiopulmonary pathologies (CHD, COPD, CKD, NYHA > III)
Trial locations and contacts
2 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
2 sites in 2 countries
United States1 site, 1 recruiting
- Recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02114
Lorenzo Berra, MD
About this study
In this study, the investigators will follow two small cohorts of pregnant women: a cohort of healthy women with uncomplicated pregnancies residing at high altitude, a control group of healthy women with uncomplicated pregnancies residing at sea level, to characterize differences in cardiopulmonary adaptation and nitric oxide (NO) pathway expression at elevations >3,500 m throughout pregnancy and into the postpartum period. The investigators aim to investigate right-sided cardiac impairment induced by chronic hypobaric hypoxemia, its effects on fetal growth, and the potential contribution of cardiovascular nitric oxide depletion to obstetric complications.
Read the detailed description
To investigate cardiac impairment, the investigators will perform transthoracic echocardiography in all enrolled pregnant women and infants, with a focus on right-sided cardiac anatomy and function, including pulmonary artery pressures, right ventricular thickness, right ventricular systolic performance, and indices of pulmonary vascular load.
To investigate the effects of hypobaric hypoxia on fetal growth, the investigators will measure intrauterine and post-delivery growth parameters, assess placental weight and histologic features, and correlate these findings with maternal oxygenation status and altitude exposure.
To assess nitric oxide production and consumption, the investigators will quantify nitric oxide-related metabolites (NO metabolomics) in maternal blood, umbilical cord blood, and placental tissue in both cohorts, and correlate these biomarkers with pulmonary arterial pressures, and right ventricular function. The investigators will also assess flow-mediated dilation in the high altitude cohort and relate these measures of endothelial function to pulmonary vascular and obstetric outcomes.
- Conditions
- Hypertensive Disorder of Pregnancy, Pulmonary Arterial Hypertension, Intrauterine Growth Restriction
- Medical subject headings
- Toxemia, Pulmonary Arterial Hypertension, Fetal Growth Retardation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Healthy pregnant women residing at high altitude | Women with uncomplicated pregnancy. | |
| Healthy pregnant women residing at sea level | Women with uncomplicated pregnancy. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pulmonary artery pressures
Measurement will be performed by transthoracic echocardiography.
Measured: Late pregnancy (35 ± 4 weeks gestation) and postpartum (6 ± 0.3 weeks)
Echographic estimate of fetal weight
Measured: Late pregnancy (35 ± 4 weeks gestation)
Nitric oxide metabolites
Measurement will be performed with a chemiluminescence assay.
Measured: Late pregnancy (35 ± 4 weeks gestation) and postpartum (6 ± 0.3 weeks) for maternal samples, at delivery (neonatal samples)
RV remodeling echocardiography parameters
Measured: Late pregnancy (35 ± 4 weeks gestation) and postpartum (6 ± 0.3 weeks)
Weight at birth
Measured: At delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2025
- Study start11 Feb 2026
- Primary completionDec 2026 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hypertensive Disorder of PregnancyStudies of the same condition, open and under way.
- More trials run by Massachusetts General HospitalThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 27 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Massachusetts General Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lorenzo Berra, MD, Massachusetts General Hospital
- Investigators
- Lorenzo Berra, MD, Principal investigator, Massachusetts General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07312227
- Sponsor's protocol ID
- PregHigh
- Status last verified
- May 2026
- First submitted
- 3 Dec 2025
- Last updated
- 26 May 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No