What are potential causes of postpartum hemorrhage?

Postpartum hemorrhage is a significant obstetric emergency characterized by excessive bleeding after childbirth, typically defined as blood loss exceeding 500 mL following vaginal delivery or 1000 mL following cesarean delivery.

The correct response highlights two common and critical causes of postpartum hemorrhage: uterine atony and retained placenta. Uterine atony, which refers to the failure of the uterus to effectively contract after delivery, is the most frequent cause of early postpartum hemorrhage. When the uterus does not contract well, it fails to compress the blood vessels that were supplying the placenta during pregnancy, leading to significant blood loss.

Retained placenta is another important cause. If parts of the placenta remain adhered to the uterine wall after delivery, it prevents the uterus from contracting properly, which can also result in substantial bleeding. This situation can require surgical intervention to address the retained tissue and stop the hemorrhage.

While trauma to the birth canal and coagulopathy are relevant to postpartum hemorrhage, the combination of uterine atony and retained placenta represents a broader and more prevalent category of causes that clinicians must be particularly vigilant about in the postpartum period. Understanding both of these causes helps in prevention and management strategies for postpartum hemorrhage.