## Core Concept
Vasa previa is a condition where fetal blood vessels are present in the membranes covering the cervical os, unsupported by either the umbilical cord or placental tissue. This condition poses a significant risk of fetal hemorrhage and death if these vessels rupture during labor or membrane rupture.

## Why the Correct Answer is Right
The correct answer choice isn't directly provided, but we can infer that the question seeks an exception to characteristics or implications of vasa previa. Typically, vasa previa is associated with a high risk of fetal mortality if the vessels rupture. The condition often requires careful management, including possible preterm delivery or in utero monitoring.

## Why Each Wrong Option is Incorrect
Without specific details on options A, B, C, and D, we can still provide a general explanation for why incorrect statements about vasa previa would be wrong:
- **Option A:** If a statement claims that vasa previa has a low risk of fetal mortality, it would be incorrect because the condition is known for its high risk of fetal death if the vessels rupture.
- **Option B:** If a statement suggests that vasa previa is commonly associated with a specific placental abnormality (e.g., velamentous cord insertion), it might be correct rather than incorrect, depending on the specifics.
- **Option C:** If a statement implies that vasa previa does not require intervention, it would be incorrect because management strategies, including delivery planning, are crucial.
- **Option D:** If a statement provides an incorrect anatomical description of vasa previa, it would be wrong based on the definition of the condition.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **velamentous cord insertion** is a condition where the umbilical cord inserts into the fetal membranes rather than directly into the placenta, and it is associated with an increased risk of vasa previa. Recognizing this association can help in the early identification and management of vasa previa.

## Correct Answer: D.