Laboratory tests for the ReMAPP study.

BackgroundAnemia affects one in three pregnant women worldwide, with the greatest burden in South Asia and sub-Saharan Africa. During pregnancy, anemia has been linked to an increased risk of adverse maternal and neonatal health outcomes. Despite widespread recognition that anemia can complicate pregnancy, critical gaps persist in our understanding of the specific causes of maternal anemia and the cutoffs used to diagnose anemia in each trimester and in the postpartum period.Methods and analysisThe Redefining Maternal Anemia in Pregnancy and Postpartum (ReMAPP) study is a multisite, prospective, cohort study nested within the Pregnancy Risk, Infant Surveillance, and Measurement Alliance (PRISMA) Maternal and Newborn Health study. Research sites are located in Kenya, Ghana, Zambia, India, and Pakistan. Participants are up to 12,000 pregnant women who provide serial venous blood samples for hemoglobin assessment at five time points: at Ethics and disseminationThe study received local and national ethical approvals from all participating institutions. Findings from multisite analyses will be published among open-access, peer-reviewed journals and disseminated with local, national, and international partners.Strengths and limitationsNovel study design to allow multiple analytical approaches (clinical decision limits and reference limits) in the same population to establish hemoglobin thresholds.Use of gold standard methods and external quality assurance programs to ensure harmonized hemoglobin measurement across sites.Inclusion of biomarker-intensive study arm to examine the etiology of anemia among pregnant women.All data is contributed by populations historically underrepresented in research in low- and middle-income countries.Trials registrationClinicalTrials.gov (PRISMA-MNH 2022; NCT05904145).