Which condition characterized by anemia is commonly seen during the second trimester?

Iron-deficiency anemia is the correct choice because it is the most common form of anemia encountered during the second trimester of pregnancy. During this period, a woman's blood volume increases significantly to support the growing fetus, which can dilute the existing red blood cells and lead to lower hemoglobin concentrations. If dietary iron intake is insufficient to meet the increased demands of pregnancy, iron-deficiency anemia can occur.

Pregnant women have an increased need for iron to support both fetal development and the expansion of maternal blood volume. The second trimester is particularly critical for iron, as this is when the fetus begins to accumulate iron stores in preparation for birth. Therefore, screening for and managing iron-deficiency anemia is essential during this stage to ensure both maternal and fetal health.

Other types of anemia, such as sickle cell anemia, thalassemia, and folate deficiency anemia, can certainly occur during pregnancy, but they are not as prevalent as iron-deficiency anemia in this specific context. Sickle cell anemia is a genetic disorder, thalassemia is typically inherited and presents differently, and folate deficiency anemia, while important, is less common specifically during the second trimester compared to iron-deficiency anemia, which is directly related to the physiological changes of pregnancy.