This cross-sectional study aims to establish reference intervals for iron biomarkers-including serum iron, ferritin, total iron-binding capacity (TIBC), and transferrin saturation (TSAT)-in healthy pregnant women during the first trimester. Additionally, the study will investigate the current prevalence of non-anemic iron deficiency (NAID) in this population. By applying strict inclusion and exclusion criteria to eliminate potential confounding factors, the study seeks to provide a reliable baseline for evaluating iron status and early detection of iron deficiency without anemia among pregnant women.