Final answer:
The leading cause of early postpartum hemorrhage (PPH) is uterine atony, which occurs when the uterus fails to contract properly after delivery. This prevents the constriction of blood vessels and can lead to excessive bleeding. The myometrium's contractions during and after delivering the placenta are crucial for minimizing blood loss.
Step-by-step explanation:
The leading cause of early postpartum hemorrhage (PPH) is uterine atony. Uterine atony is a condition where the uterus fails to contract effectively after childbirth. This can lead to excessive bleeding because the contractions of the uterus are essential to constrict blood vessels where the placenta was attached. When the uterus does not contract strongly enough, these vessels can continue to bleed. The delivery of the placenta marks the final stage of childbirth, and the myometrium's continuous contractions help shear the placenta from the back of the uterine wall, reducing the risk of bleeding.
Breastfeeding facilitates the process of uterine involution, which is the contraction and shrinking of the uterus to its pre-pregnancy size. Retained placental fragments can also cause PPH, but they are not the leading cause. It is crucial that the placenta is examined post-delivery to ensure no pieces remain that could cause complications.
While the presence of retained placental fragments, subinvolution of the uterus, and pelvic infection are other possible causes of PPH, uterine atony is indeed the most common cause and is responsible for the majority of early postpartum bleeding cases. It is vital for healthcare providers to quickly identify and manage uterine atony to prevent severe blood loss.