Most common cause of post paum hemorrhage: September 2009
## **Core Concept**
Postpartum hemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide. It is defined as excessive bleeding following the delivery of the baby, typically more than 500 mL after a vaginal delivery or more than 1000 mL after a cesarean section. The causes of PPH can be categorized into four main areas: uterine atony, lacerations, retained placental tissue, and coagulopathy.
## **Why the Correct Answer is Right**
The most common cause of postpartum hemorrhage is **uterine atony**, which accounts for approximately 70-80% of all PPH cases. Uterine atony refers to the failure of the uterus to contract down effectively after delivery, leading to excessive bleeding from the site where the placenta was attached. This condition occurs because the myometrium fails to contract down properly, often due to overdistension of the uterus (as in multiple gestations or polyhydramnios), prolonged labor, or the use of certain medications like magnesium sulfate.
## **Why Each Wrong Option is Incorrect**
- **Option A:** Lacerations, although a cause of postpartum hemorrhage, are not the most common cause. They can occur during delivery and may lead to significant bleeding, but they are not as frequently associated with PPH as uterine atony.
- **Option C:** Retained placental tissue can cause PPH by preventing the uterus from contracting down properly. However, it is less common than uterine atony as a cause of PPH.
- **Option D:** Coagulopathy, or disorders of blood clotting, can also lead to PPH but is a much rarer cause compared to uterine atony.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl to remember is the "4 Ts" of postpartum hemorrhage: **Tone** (uterine atony), **Trauma** (lacerations), **Tissue** (retained placental tissue), and **Thrombin** (coagulopathy). Uterine atony is the most common cause and often the first to be considered and treated. Early recognition and management of PPH, including the administration of uterotonic agents like oxytocin, are critical to prevent severe morbidity and mortality.
## **Correct Answer:** . Uterine Atony