PRESHA — Preventing severe hypertensive adverse events in pregnancy and childbirth: a study protocol for establishing a prospective cohort study and biobank in urban Tanzania
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Objectives Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal mortality in low- and middle income settings. Yet, to date few large-scale prospective clinical studies in this field are conducted in sub-Saharan Africa. This paper describes the study protocol of a prospective cohort study, the PRESHA (PREventing Severe Hypertensive Adverse Events) cohort in Mwanza, Tanzania. The PRESHA study aims to reduce maternal and neonatal mortality and morbidity related to preeclampsia (PE) through improved prediction, prevention and clinical management. More specifically, within the cohort we aim to improve antenatal risk prediction of PE by externally validating existing biomarker-based (PlGF and sFlt-1) risk prediction models. Methods and design Recruitment for a prospective cohort study of 3,000 women started August 2025 and is ongoing. Eligible for enrolment are women between 10to 16weeks of pregnancy at booking for antenatal care. Socio-demographic, environmental, clinical, health behaviours, resource use and care satisfaction data will be collected up to 12 weeks postpartum. Biological samples (serum, plasma, urine) will be collected at up to five moments: at 10≤ 15weeks, 19≤ 23weeks, 27≤ 31weeks, upon diagnosis and at birth (including placenta biopsy). Main outcomes are confirmed diagnosis of PE and adverse maternal and perinatal outcomes. Biomarker analysis (sFlt-1 and PlGF) will commence after completed recruitment. We will establish gestational age
Abstract
Objectives Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal mortality in low- and middle income settings. Yet, to date few large-scale prospective clinical studies in this field are conducted in sub-Saharan Africa. This paper describes the study protocol of a prospective cohort study, the PRESHA (PREventing Severe Hypertensive Adverse Events) cohort in Mwanza, Tanzania. The PRESHA study aims to reduce maternal and neonatal mortality and morbidity related to preeclampsia (PE) through improved prediction, prevention and clinical management. More specifically, within the cohort we aim to improve antenatal risk prediction of PE by externally validating existing biomarker-based (PlGF and sFlt-1) risk prediction models. Methods and design Recruitment for a prospective cohort study of 3,000 women started August 2025 and is ongoing. Eligible for enrolment are women between 10to 16weeks of pregnancy at booking for antenatal care. Socio-demographic, environmental, clinical, health behaviours, resource use and care satisfaction data will be collected up to 12 weeks postpartum. Biological samples (serum, plasma, urine) will be collected at up to five moments: at 10≤ 15weeks, 19≤ 23weeks, 27≤ 31weeks, upon diagnosis and at birth (including placenta biopsy). Main outcomes are confirmed diagnosis of PE and adverse maternal and perinatal outcomes. Biomarker analysis (sFlt-1 and PlGF) will commence after completed recruitment. We will establish gestational age (GA)-specific population reference values for these biomarkers, and describe the predictive accuracy of the biomarkers and biometric parameters for screening of PE. For existing prognostic models, we will evaluate the predictive performance in our cohort in terms of discrimination (area under the receiver operating characteristics curve) and calibration (calibration plot). Discussion This prospective cohort study offers comprehensive and contextually relevant data contributing to improving antenatal risk prediction for PE in a low-resource setting. The establishment of a new pregnancy database in Tanzania allows for identification of the impact of social or environmental determinants of health, risks of pregnancy complications and effect of health seeking behaviour. Future discovery studies of other predictors and diagnostics tools for placenta disorders will be possible with the established biobank.