The CARES study: Cardiometabolic Adolescent REproductive health in Sierra Leone: Assessing Underlying Cardiometabolic Mechanisms in Adolescents With Preeclampsia
THE PROBLEM
Sierra Leone, ranked 184th out of 193 countries on the Human Development Index, has one of the highest maternal mortality rates in the world at 443 deaths per 100,000 live births. The leading causes are obstetric haemorrhage (39.4%), preeclampsia (15.8%), and pregnancy-related infections (10.1%). Adolescents are especially vulnerable, accounting for 40% of maternal deaths nationally, with teenage pregnancy rates of 28.3% to 34%. The eclampsia rate in Sierra Leone is 142 per 10,000 births, compared with 2.7 per 10,000 in the UK. International evidence shows that adolescents aged 15 to 17 face a 30% higher risk of severe maternal morbidity and are 3.5 times more likely to develop eclampsia than women over 19. Despite this, the metabolic, cerebrovascular, and cardiovascular mechanisms driving the elevated risk in adolescents remain poorly understood, particularly in resource-poor settings.
HYPOTHESIS
Adolescent mothers experience unique physiological changes during pregnancy that increase their susceptibility to the harmful effects of preeclampsia compared with adult women. These changes likely involve differences in cardiovascular, metabolic, and inflammatory responses, shaped by the immaturity of adolescent bodies and compounded by socioeconomic factors. Understanding these mechanisms is crucial to reducing morbidity and mortality in this vulnerable group.
STUDY DESIGN
CARES is a prospective observational feasibility study at Princess Christian Maternity Hospital and Aberdeen Women’s Centre in Freetown, recruiting 160 participants (40 per group) across four groups: adolescents (<20 years) and adults (≥20 years), with and without preeclampsia. Participants are assessed at three time points: enrolment (28 to 40+ weeks gestation), within one week of delivery, and 6 weeks to 3 months postpartum. Each visit includes echocardiography, peripheral vascular assessment (Vicorder PWV and AIx), point-of-care biomarkers (PlGF, GlyFn, BNP, U&Es including creatinine), NMR metabolomics, blood pressure, nutritional status, and questionnaires capturing socioeconomic and gynaecological data
OBJECTIVES
Primary (feasibility): To assess the feasibility of profiling cardiometabolic differences between women with preeclampsia and normotensive pregnancies in Sierra Leone using echocardiography, peripheral vascular assessment, cardiac and placental biomarkers, and metabolomic profiling.
Secondary (exploratory): To explore age-related cardiovascular and cardiometabolic patterns comparing adolescents (<20 years) and adults (≥20 years) in both preeclampsia and normotensive pregnancies, to generate hypotheses informing the design of a definitive study.
SIGNIFICANCE
CARES is the first step in addressing a critical gap in understanding the cardiovascular and metabolic mechanisms behind preeclampsia in adolescents. Before that question can be answered, we first need to establish whether collecting this information is feasible in this setting. By focusing on young mothers in a low-resource context, the study will generate the effect sizes, dispersion, and feasibility parameters needed to power a definitive cohort study or trial that can ask whether adolescent preeclampsia represents a distinct disease phenotype. Findings will contribute to global strategies to reduce maternal mortality and support Sustainable Development Goal 3.1, which seeks to reduce maternal mortality to fewer than 70 deaths per 100,000 live births by 2030.
