Which hormone is released during childbirth to help with milk ejection?

The hormone that is released during childbirth to aid in milk ejection is oxytocin. This hormone plays a crucial role in several aspects of the reproductive process, including stimulating uterine contractions during labor and facilitating the release of milk during breastfeeding.

When a baby suckles at the breast, sensory signals from the nipple reach the brain, prompting the release of oxytocin from the posterior pituitary gland. This hormone then acts on the myoepithelial cells surrounding the milk-producing glands, causing them to contract and thereby eject milk into the ducts where it can be accessed by the breastfeeding infant. This mechanism is often described as the "let-down reflex."

Prolactin, while important for milk production, does not have a direct role in the milk ejection process; its primary function is to stimulate the synthesis of milk in the mammary glands. Corticotropin (also known as ACTH) and TSH (thyroid-stimulating hormone) are involved in different physiological processes unrelated to childbirth or lactation. Therefore, oxytocin is specifically recognized for its essential role in the ejection of milk during breastfeeding following childbirth.