## **Core Concept**
External cephalic version (ECV) is a procedure used to manually turn a fetus from a breech position to a cephalic (head-down) position. The safety and success of ECV depend on various factors, including the gestational age, fetal well-being, and certain maternal and fetal conditions. Contraindications to ECV are crucial to identify to avoid complications.

## **Why the Correct Answer is Right**
The correct answer, , indicates that a condition where ECV is contraindicated is when there is a history of **previous uterine surgery**, particularly a **previous cesarean section** or a **previous myomectomy** involving a uterine incision. This is because the procedure could potentially lead to uterine rupture, especially if there is a scar in the uterus from a previous surgery.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not specified, but generally, conditions like **multiple gestations** or **severe preeclampsia** might be contraindications, but without specifics, it's hard to directly refute.
- **Option B:** Similarly, this option lacks detail but conditions such as **placenta previa** or **abnormal fetal heart rate tracing** indicating fetal distress could be reasons for caution or contraindication.
- **Option C:** This option might refer to conditions like **fetal growth restriction** or **oligohydramnios**, which could pose challenges but are not absolute contraindications depending on the clinical scenario.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **previous uterine surgery**, especially a **cesarean section**, is a significant concern for ECV due to the increased risk of **uterine rupture**. Always assess the risk-benefit ratio and consider alternatives in such cases.

## **Correct Answer:** D. Previous uterine surgery.