Which is a predisposing factor for postpartum hemorrhage due to uterine atony?

• A. Multiparity with uterine overdistention
• B. Prolonged labor
• C. Use of uterotonic drugs
• D. Preexisting hypertension

Answer: (A)

Uterine atony occurs when the uterus fails to contract effectively after delivery, leaving freshly cut blood vessels poorly compressed and prone to bleeding. When the uterus is overdistended, its myometrium is stretched and less capable of generating strong, coordinated contractions. This is exactly what happens with multiparity accompanied by uterine overdistention: the uterus has been stretched over time and loses some contractile efficiency, making it more likely to bleed after birth. Prolonged labor can also tax the uterine muscles, but the most direct and impactful predisposition among these factors is a stretched, overdistended uterus. In contrast, uterotonic drugs help promote contraction and reduce the risk of atony, while preexisting hypertension does not directly cause the uterus to fail to contract.