What is hydrops fetalis?

Hydrops fetalis is a serious condition characterized by the accumulation of abnormal amounts of fluid in two or more fetal compartments, such as the abdomen, lungs, or skin. This condition often indicates underlying issues, making it a significant indicator of prenatal complications.

When fluid accumulates in the fetal spaces, it suggests that the fetus may be experiencing significant stress or may have conditions such as heart defects, anemia, or infections. Since the condition can lead to severe fetal distress and can be life-threatening, it is often associated with a form of heart failure due to the heart's inability to handle the increased burden of fluid. This explains why the correct choice defines hydrops fetalis as a prenatal form of heart failure characterized by fluid accumulation.

In this context, the other choices do not accurately describe hydrops fetalis. While low blood flow, fetal stress responses, or increased heart rates can be associated with various fetal conditions, they do not encapsulate the distinct nature of hydrops fetalis, which primarily involves fluid accumulation and is closely linked to heart failure.