Normocytic anemia in pregnancy is most consistent with which condition?

• A. Iron deficiency anemia
• B. Folate deficiency
• C. Physiologic anemia of pregnancy
• D. Vitamin B12 deficiency

Answer: (C)

The main idea is that pregnancy often causes a dilutional, physiologic anemia. During pregnancy, plasma volume expands substantially—more than red cell mass does—so the blood becomes more fluid, and hemoglobin concentration falls even though the red cells themselves are still normal in size. This yields a normocytic, normochromic picture, which is typical of physiologic anemia of pregnancy.

Iron deficiency would lower hemoglobin too, but it tends to produce microcytosis (smaller-than-normal red cells) with a low MCV and hypochromia, reflecting reduced iron availability. Folate or vitamin B12 deficiencies, on the other hand, cause macrocytic anemia (increased MCV) due to impaired DNA synthesis and larger red cells. So the normal red cell size in pregnancy points to physiologic dilutional anemia rather than a nutritional deficiency.