**Question:** Most common cause of secondary postpartum hemorrhage (PPH) is -

A. Atony
B. Placenta praevia
C. Placenta accreta
D. Coagulopathy

**Core Concept:** Postpartum hemorrhage (PPH) is defined as bleeding more than 500 mL or 10% of blood volume in the first 24 hours after childbirth. Secondary PPH refers to bleeding caused by specific underlying conditions.

**Why the Correct Answer is Right:** The most common cause of secondary PPH is **D. Coagulopathy**. Coagulopathy refers to a decrease in the ability of the blood to clot, which can result from various factors, including liver disease, drug-induced liver injury, or vitamin K deficiency. In the setting of secondary PPH, coagulopathy impairs the formation of blood clots, leading to increased blood loss during childbirth.

**Why Each Wrong Option is Incorrect:**

A. **Atony** (uterine muscle weakness) is a primary cause of PPH, where uterine involution fails to occur, leading to excessive bleeding. Atony is not the primary cause of secondary PPH, as the latter is caused by a specific underlying condition.

B. **Placenta praevia** is a condition where the placenta is located abnormally low in the uterus, increasing the risk of PPH. However, placenta praevia is not the most common cause of secondary PPH, as coagulopathy is the primary reason.

C. **Placenta accreta** is a type of placenta praevia where the placenta invades deeply into the uterine wall, leading to increased risk of PPH. Similar to placenta praevia, placenta accreta is not the most common cause of secondary PPH, as coagulopathy is the primary reason.

**Clinical Pearls:**

1. Understanding the primary causes of PPH (e.g., atony) is essential to identify potential secondary causes such as coagulopathy.
2. Proper assessment and management of coagulopathy are crucial in preventing and treating secondary PPH. Early recognition and intervention are essential in reducing maternal mortality rates.
3. Coagulation disorders can be associated with other complications, such as disseminated intravascular coagulation (DIC) and disseminated atherosclerosis.

**Core Concept Explanation:**

Postpartum hemorrhage (PPH) is a significant cause of maternal mortality globally. Secondary PPH can occur due to various underlying conditions. Atypical causes of PPH include coagulation disorders (e.g., DIC, disseminated atherosclerosis), which lead to bleeding disorders (e.g., platelets, clotting factors) and resultant decreased clotting ability. These conditions are responsible for secondary PPH due to impaired blood clotting.

**Why Each Wrong Option is Incorrect:**

Atony, placenta praevia, and placenta accreta are primary causes of postpartum hemorrhage (