Iron Deficiency in Pregnancy

Clinical Manifestations

Iron deficiency represents a spectrum from iron depletion to iron-deficient erythropoiesis to frank anemia, and symptoms can occur before hemoglobin drops below diagnostic thresholds, according to Praxis Medical Insights 1
Impaired neurocognitive function is associated with iron deficiency, which affects brain development and function even before anemia develops, as reported by Blood Reviews 2
Mood disturbances, including changes in serotonin, norepinephrine, and dopamine levels, are linked to iron deficiency, as noted by Blood Reviews 2

Standard hemoglobin/hematocrit screening may miss iron deficiency without anemia, as these tests only detect anemia once iron stores are severely depleted, as stated by Annals of Internal Medicine 3 and 4
Low serum ferritin is a marker of iron deficiency, but it has limitations in pregnancy, as it decreases in late pregnancy despite adequate bone marrow iron stores, according to Annals of Internal Medicine 4
Serum ferritin is an acute phase reactant, which can be falsely elevated in the presence of inflammation or infection, as reported by Annals of Internal Medicine 4

18.6% of pregnant women have iron deficiency, but only 16.2% of those also have anemia, meaning a substantial proportion have iron deficiency without meeting anemia criteria, as found by American Family Physician 5 and 6
High-risk groups for iron deficiency include women with diets lacking iron-rich foods, non-Hispanic Black and Mexican American women, women with gastrointestinal conditions, and women with short intervals between pregnancies, as identified by American Family Physician 5, 6, and Praxis Medical Insights 1

Both iron deficiency with and without anemia are associated with adverse outcomes, including impaired neurocognitive development in children and suboptimal immune responses, as reported by Blood Reviews 2
Low birth weight is a potential risk associated with iron deficiency, as noted by MMWR Recommendations and Reports 7 and 8