A healthy, 44-year-old woman, G2, P1, has a screening ultrasound at 18 weeks’ gestation that shows no fetal anomalies. There is decreased fetal movement at 32 weeks’ gestation, and ultrasound shows fetal growth restriction with relative sparing of the fetal head. The placenta appears normally positioned in the lateral fundus, but appears small, and the amniotic fluid index is reduced. Maternal blood pressure is normal. Which of the following conditions is most likely to be present?

**Core Concept**
The case describes fetal growth restriction (FGR), a condition characterized by inadequate fetal growth due to placental insufficiency, which can lead to decreased fetal movement and increased risk of perinatal mortality.

**Why the Correct Answer is Right**
Fetal growth restriction is often associated with placental abruption, a condition where the placenta separates from the uterus, leading to decreased placental blood flow and oxygen delivery to the fetus. In this case, the normally positioned but small placenta and reduced amniotic fluid index support the diagnosis of placental abruption. The relative sparing of the fetal head indicates that the abruption may be partial or incomplete, allowing for some continued fetal growth.

**Why Each Wrong Option is Incorrect**
**Option A:** Placenta previa is a condition where the placenta covers the internal cervical os, but it is not directly associated with fetal growth restriction or decreased fetal movement.
**Option B:** Fetal macrosomia refers to excessive fetal growth, which is the opposite of fetal growth restriction.
**Option C:** Chorioamnionitis is an infection of the fetal membranes, which can cause preterm labor and fetal distress, but it is not directly associated with fetal growth restriction or a normally positioned placenta.

**Clinical Pearl / High-Yield Fact**
Fetal growth restriction is a leading cause of perinatal mortality, and early detection through ultrasound and maternal surveillance is crucial for improving outcomes.

**Correct Answer:** C. Placental abruption.

✓ Correct Answer: A. Uteroplacental insufficiency