What causes afterbirth pains to occur?

Afterbirth pains, also known as postpartum contractions or afterpains, are primarily caused by the contraction of the uterus after delivery. Following childbirth, the uterus must return to its pre-pregnancy size and shape, a process that involves rhythmic contractions. These contractions are crucial for helping to expel any remaining placental tissue and reducing the risk of postpartum hemorrhage.

Afterbirth pains are often more noticeable after subsequent pregnancies since the uterine tone and muscle memory have changed, leading to more intense contractions. These contractions are similar in nature to those experienced during labor, but they serve the specific purpose of assisting the uterus in regaining its normal state and facilitating healing.

In contrast, factors such as ovulation resuming, movement of the baby, or general hormonal changes during pregnancy do not directly contribute to afterbirth pains. Ovulation typically resumes later postpartum, and the movements of the baby are not relevant after delivery as the baby has already been born. Hormonal changes do play a role throughout pregnancy and postpartum but are not the primary cause of the immediate uterine contractions that lead to afterbirth pains.