## **Core Concept**
Maternal mortality encompasses deaths occurring during pregnancy or within 42 days of delivery, due to any cause related to or aggravated by the pregnancy or its management. The leading causes of maternal mortality globally include hemorrhage, eclampsia, obstructed labor, sepsis, and unsafe abortion. Rare causes do contribute but are less frequently encountered.

## **Why the Correct Answer is Right**
Thromboembolism, which includes both pulmonary embolism and amniotic fluid embolism, is considered a rare but significant cause of maternal mortality. It is often cited as one of the less common causes compared to postpartum hemorrhage or eclampsia but is highly fatal when it occurs. The correct answer being thromboembolism highlights its impact despite its lower incidence compared to other causes.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While hemorrhage is a leading cause of maternal mortality worldwide, it is not considered rare; rather, it is one of the most common causes.
- **Option B:** Similarly, eclampsia is a major cause of maternal and fetal morbidity and mortality, particularly in low-resource settings, and is not rare.
- **Option C:** Obstructed labor is another significant cause of maternal mortality, particularly in areas with limited access to emergency obstetric care, and is not considered rare.
- **Option D:** Sepsis, often related to postpartum infection, is also a leading cause of maternal mortality and is not rare.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that while thromboembolism (including pulmonary embolism and amniotic fluid embolism) is a rare cause of maternal mortality, it is highly lethal and often unexpected. Its rarity can make it harder to diagnose promptly, emphasizing the importance of awareness and vigilance for this condition.

## **Correct Answer:** D. Thromboembolism