What is a common sign of fetal anemia associated with hydrop fetalis?

Fetal anemia, particularly in the context of hydrops fetalis, often leads to a series of physiological changes in the fetus. An enlarged heart, or cardiomegaly, is a common sign associated with fetal anemia. This occurs because anemia results in the heart working harder to compensate for the lower oxygen-carrying capacity of the blood. The heart must pump more vigorously to supply adequate oxygen and nutrients to the fetal tissues, leading to hypertrophy and enlargement over time.

In the case of hydrops fetalis, which is characterized by an abnormal accumulation of fluid in the fetal compartments, the effects of severe anemia can be exacerbated. The increased fluid load and stress on the cardiovascular system can result in further enlargement of the heart.

Other options, while they may present in various conditions, do not specifically correlate with the classic signs of fetal anemia associated with hydrops. For instance, an increased heart rate could be a result of various fetal stressors, but it is not as specific to the anemia itself. A smaller abdomen is more characteristic of growth restriction rather than anemia, and while yellowing of the eyes indicates jaundice, it is more directly related to hemolytic diseases of the newborn rather than fetal anemia itself. Thus, an enlarged