Baby’s sucking stimulates the release of two hormones, oxytocin and prolactin. Oxytocin signals your uterus to contract and return to its pre-pregnancy size. This is why many women experience uterine cramping during the first few days of nursing. Oxytocin also contracts tiny muscles in the breast to release milk to the baby. This is called the "let down" reflex.
The hormone prolactin stimulates your breast to produce milk. The "first milk" is a substance called colostrum, which is nutritionally complete with protective antibodies that are very beneficial to newborns. Colostrum is produced in very small quantities (perfectly designed for a newborn’s small stomach). Colostrum provides all the nutrition your baby needs for her/his first days of life. Colostrum varies in color and consistency and transitions into a thinner liquid called transitional milk before becoming mature milk about two weeks postpartum. Mature milk is thin and white in color and resembles the appearance of skim milk.
The more your baby nurses, the more milk your body will produce. The amount of milk removed from the breast determines the amount of milk produced. A pattern of supply and demand is established with each feeding. Drink a glass of water, juice or milk at every feeding to ensure that you are adequately hydrated. It is also important for you to maintain a healthy diet by eating a variety of fresh, nourishing foods like fruits, vegetables, proteins and grains. It is not necessary for your baby to drink water, formula or other liquids in addition to breast milk unless prescribed by your healthcare provider. You do not have to drink cow's milk to produce human milk.
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