**Core Concept**
Post-term pregnancy, also known as postdates pregnancy, occurs when a pregnancy extends beyond 42 weeks of gestation. This condition is associated with an increased risk of various complications due to the prolonged exposure to the intrauterine environment.

**Why the Correct Answer is Right**
The primary concern in post-term pregnancy is the increased risk of fetal hypoxia and acidosis due to the decreased placental function and reserve. This can lead to neonatal complications such as meconium aspiration syndrome, birth asphyxia, and even stillbirth. Additionally, post-term pregnancies have a higher risk of placental abruption and uterine rupture, especially in women who have had previous uterine surgery.

**Why Each Wrong Option is Incorrect**
**Option A:** Placenta previa is actually more common in multiple gestations, previous uterine surgery, or in pregnancies with a history of placenta previa in a previous pregnancy. It is not specifically associated with post-term pregnancy.
**Option B:** Fetal growth restriction (FGR) is more commonly associated with preterm pregnancies, as the placental function is impaired, leading to inadequate fetal growth. In post-term pregnancies, the main concern is fetal overgrowth and macrosomia.
**Option C:** Uterine rupture is a known complication of post-term pregnancy, especially in women with a history of uterine surgery or previous uterine rupture. The prolonged exposure to the intrauterine environment increases the risk of uterine dehiscence and rupture.

**Clinical Pearl / High-Yield Fact**
In post-term pregnancies, the risk of stillbirth increases significantly after 42 weeks of gestation. It is essential to closely monitor fetal well-being and consider induction of labor after 42 weeks to reduce the risk of adverse outcomes.

**Correct Answer: A. Placenta previa.**