**Core Concept**
Antenatal support, also known as fetal support, refers to the structures and mechanisms that provide mechanical support to the developing fetus during pregnancy. This support is essential for fetal growth, development, and well-being.

**Why the Correct Answer is Right**
The correct answer is not directly related to the mechanisms of fetal support. However, since the question asks for what does 'NOT deliver' antenatal support, we need to identify the structures that do not contribute to it. Antenatal support is primarily provided by the amniotic fluid and the umbilical cord. The amniotic fluid provides a cushioning effect, while the umbilical cord delivers oxygen and nutrients to the fetus. The placenta, however, does not deliver antenatal support but rather provides a site for gas and nutrient exchange between the fetus and the mother.

**Why Each Wrong Option is Incorrect**
**Option A:** Amniotic fluid - This is actually a key component of antenatal support, providing a cushioning effect and allowing for fetal movement.

**Option B:** Umbilical cord - This is another crucial component of antenatal support, delivering oxygen and nutrients to the fetus.

**Option C:** Placenta - Although the placenta is essential for fetal development, it does not directly deliver antenatal support but rather facilitates gas and nutrient exchange.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that antenatal support is a critical aspect of fetal development, and understanding the mechanisms of support can help clinicians identify potential issues during pregnancy.

**Correct Answer:** C. Placenta.