The normal range of prolactin in women after pregnancy is around 10-210ng/ml. Prolactin levels are higher after pregnancy than during non-pregnancy, and appropriate high levels of prolactin can promote the development of the mammary glands, thus preparing them for the production of milk after delivery. The range of normal values of prolactin after pregnancy is wide and the test is influenced by the woman’s mental state, diet, and rest. In early pregnancy, the levels of estrogen, progesterone and lactogen increase, and the increase in lactogen promotes the development of the milk ducts and alveoli, making the breasts larger and softer, and the areola and nipples larger and more colored, which also prepares the baby for breastfeeding after delivery.