NCT07312227

A Prospective Longitudinal Observational Cohort Study of Pregnant Women Residing at High Altitude in Bolivia

• Status: Not Yet Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 20 (estimated)
• Sponsor: Massachusetts General Hospital · Academic / Other
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

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, and a hospitalized cohort of symptomatic women with pregnancies complicated by obstetric conditions (e.g., preeclampsia), 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 such as preeclampsia, pulmonary arterial hypertension, and right ventricular dysfunction.

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 preeclampsia, pulmonary arterial hypertension, and right ventricular dysfunction. The investigators will also assess flow-mediated dilation in symptomatic and asymptomatic participants and relate these measures of endothelial function to pulmonary vascular and obstetric outcomes.

Conditions

• Hypertensive Disorder of Pregnancy
• Pulmonary Arterial Hypertension
• Intrauterine Growth Restriction

Timeline

• Start date: 2026-02-01
• Primary completion: 2026-12-01
• Completion: 2027-02-01
• First posted: 2025-12-31
• Last updated: 2025-12-31