Prevalence of Iron Deficiency and Iron Deficiency Anemia in the First Trimester of Pregnancy

Iron deficiency is the most common cause of anemia in pregnancy. Iron requirements increase to meet the demands of maternal red cell expansion and fetal development. As part of a quality-improvement project, ferritin levels were obtained in all patients (N=1,858) presenting in the first trimester to identify iron deficiency. Anemia (hemoglobin less than 11 g/dL) was present in 75 patients (4.0%, 95% CI, 3.2–5.0) and iron deficiency (ferritin level less than 30 ng/mL) in 757 (40.7%, 95% CI, 38.5–43.0). Hemoglobin was 11 g/dL or higher in 707 (93.4%) patients with iron deficiency. Anemia was present in 25 of 1,101 (2.3%, 95% CI, 1.5–3.3) patients with normal ferritin levels. Additional research is required to determine whether earlier supplementation decreases the incidence of anemia later in pregnancy and improves outcomes.