Which of the following is a common risk factor for postpartum hemorrhage?

Retained placenta is a significant risk factor for postpartum hemorrhage because it can prevent the uterus from contracting effectively after delivery. When portions of the placenta remain attached to the uterine wall, it not only hinders uterine involution but also contributes to the continuous bleeding that can occur in postpartum women. Effective uterine contraction is essential for closing off the blood vessels that were supplying the placenta, and any retention can lead to a cascade of complications, including severe blood loss.

In contrast, factors such as minimal labor duration and frequent prenatal checkups generally do not contribute to the risk of postpartum hemorrhage. While immediate postpartum care is critical for monitoring and managing any potential bleeding, it does not in itself serve as a risk factor for hemorrhage. Understanding these distinctions is important in anticipating and managing postpartum complications effectively.