Which hormone is primarily responsible for the initiation and maintenance of lactation?

Prolactin is the hormone primarily responsible for the initiation and maintenance of lactation. It is produced by the anterior pituitary gland and plays a crucial role in breast development and the production of milk following childbirth. When a baby suckles at the breast, the stimulation of the nipple sends signals to the brain to release prolactin, which then promotes milk synthesis in the mammary glands.

This hormone operates alongside other hormones during the breastfeeding process, but its primary function is linked directly to the production of milk. Understanding the role of prolactin is essential for recognizing how breastfeeding is regulated and how various factors can influence lactation in new mothers. Other hormones listed, like follicle-stimulating hormone, estrogen, and progesterone, have various functions in reproduction and pregnancy but do not play the central role in initiating and maintaining milk secretion.