What is the cardinal sign of a significant hemorrhage in a pregnant woman?

Excessive bleeding is considered the cardinal sign of significant hemorrhage in a pregnant woman because it indicates a substantial loss of blood volume, which can pose serious risks to both the mother and the fetus. In the context of pregnancy, significant hemorrhage may result from complications such as placental abruption, placenta previa, or uterine rupture.

When a pregnant woman experiences excessive bleeding, it is critical to recognize this sign quickly as it can lead to shock and other life-threatening conditions. The amount of blood lost can quickly affect the circulatory system, depriving both the mother and the fetus of oxygen and nutrients. Therefore, prompt recognition and intervention are vital.

The other options, while important symptoms to monitor, do not specifically indicate significant hemorrhage as clearly as excessive bleeding does. Light-headedness could result from a variety of causes including dehydration or low blood pressure, belly pain might be associated with a number of different conditions in pregnancy, and marked swelling can occur for reasons unrelated to acute blood loss. Thus, the presence of excessive bleeding serves as a direct and critical indicator of a potentially life-threatening situation requiring immediate medical attention.