Final answer:
Concealed hemorrhage refers to bleeding that occurs behind the placenta and is not visible externally, while revealed hemorrhage is visible externally. This distinction is important for diagnosis and management of placental abruption.
Step-by-step explanation:
Hemorrhage occurring with placental abruption can be either concealed or revealed. Concealed hemorrhage refers to bleeding that occurs behind the placenta and is not visible externally. Revealed hemorrhage, on the other hand, refers to bleeding that is visible externally. For example, if a pregnant woman experiences heavy vaginal bleeding, it would be considered revealed hemorrhage. This distinction is important as it helps healthcare providers diagnose and manage the condition.