What is the nurse's primary concern when caring for a pregnant woman with class II cardiac disease and a hemoglobin level of 8 g/dL?

When caring for a pregnant woman with class II cardiac disease and a hemoglobin level of 8 g/dL, the primary concern is the risk of impending heart failure. Class II cardiac disease indicates that the patient has cardiac limitations with physical activity, and during pregnancy, the cardiovascular system adapts to increased blood volume and metabolic demands. Anemia, especially at such low hemoglobin levels, increases the burden on the heart because the heart must work harder to deliver adequate oxygen to the tissues.

This situation can precipitate congestive heart failure, as the mother's heart may already be under strain due to her pre-existing cardiac condition. Symptoms such as fatigue, shortness of breath, and edema may worsen and lead to significant cardiovascular complications.

While anemia does present a risk and can lead to other complications, the more immediate concern is how it impacts the cardiovascular system for someone already experiencing cardiac limitations. The possibility of fetal distress and infection risk are also factors to consider, but they are secondary to monitoring and managing the mother's cardiac status to prevent heart failure, which could have severe consequences for both her and her fetus.