**Core Concept**
Cord prolapse refers to the displacement of the umbilical cord from its normal position in the birth canal, which can lead to fetal distress and compromise oxygenation. This condition requires prompt recognition and management to prevent adverse outcomes.

**Why the Correct Answer is Right**
Cord prolapse can occur due to various factors, including multiple gestations, malpresentation, uterine anomalies, and trauma during labor. However, one of the key etiologies of cord prolapse is the presence of a non-vertex presentation, such as a breech or transverse lie, which can cause the cord to prolapse through the cervical os.

**Why Each Wrong Option is Incorrect**
**Option A:** Multiple gestations can increase the risk of cord prolapse, as there is a higher likelihood of cord entanglement and compression. Therefore, this option is not correct because it is actually a risk factor for cord prolapse.

**Option B:** Uterine anomalies, such as a bicornuate uterus, can increase the risk of cord prolapse due to the abnormal uterine shape and size. This option is not correct because it is actually a risk factor for cord prolapse.

**Option C:** Trauma during labor, such as a sudden push or a cervical examination, can cause the cord to prolapse. This option is not correct because it is actually a mechanism of cord prolapse.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that cord prolapse is a medical emergency that requires prompt recognition and management. The presence of a bulging bag of membranes or a prolapsed cord should alert the healthcare provider to the possibility of cord prolapse and prompt immediate action.

**Correct Answer:** D.