Final answer:
Uterine atony, prolonged labor, and previous pregnancies are risk factors for postpartum hemorrhage (PPH) caused by uterine factors.
Step-by-step explanation:
Postpartum hemorrhage (PPH) is a significant risk factor after childbirth. Uterine atony, which refers to the inability of the uterus to contract and clamp down after delivery, is a major cause of PPH. Prolonged labor can also increase the risk of PPH as it puts more strain on the uterus. Previous pregnancies can increase the risk as well, as the uterus may not be as strong and able to contract effectively. High caffeine intake, on the other hand, is not directly linked to uterine PPH risk factors.