Brain sparing effect on Doppler is seen in which vessel?
**Core Concept**
The brain sparing effect refers to the **cerebral blood flow** redistribution in response to hypoxia, ensuring that the brain receives adequate oxygenation. This effect is observed in the **middle cerebral artery**.
**Why the Correct Answer is Right**
The middle cerebral artery is a critical vessel supplying the brain, and its preservation is essential for maintaining **cerebral function**. In conditions of hypoxia or fetal distress, blood flow is redirected to prioritize the brain, demonstrating the brain sparing effect on **Doppler ultrasound**.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect due to its lack of direct involvement in cerebral blood flow redistribution.
**Option B:** Not directly related to the brain sparing effect.
**Option D:** Not the primary vessel demonstrating this effect.
**Clinical Pearl / High-Yield Fact**
The brain sparing effect is a significant indicator of fetal well-being, particularly in the context of **intrauterine growth restriction**.
**Correct Answer:** D. Middle Cerebral Artery