**Core Concept**
Maternal mortality refers to deaths due to complications from pregnancy or childbirth. The **postpartum period** is a critical time for maternal health.

**Why the Correct Answer is Right**
The correct answer is related to the time of highest risk for maternal mortality. The **postpartum hemorrhage** and **puerperal sepsis** are leading causes of maternal death, often occurring in the immediate **postpartum period**.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because, although pregnancy carries risks, the majority of maternal deaths occur after delivery.
**Option B:** Incorrect as the risk is not evenly distributed throughout pregnancy.
**Option D:** Incorrect because, while late pregnancy has risks, the peak is post-delivery.

**Clinical Pearl / High-Yield Fact**
Remember, the **postpartum period**, especially the first 24 hours, is crucial for monitoring and preventing complications.

**Correct Answer:** D. postpartum period