Breastfeeding is the means through which human mothers produce and deliver milk to feed their babies. Breastfeeding, also called nursing or lactation, is widely considered to be the best nourishment for infants. For its nutritional, psychological and other health benefits, breastfeeding is recommended by experts over formula feeding, ideally for the first year of life.
Women's breasts contain mammary glands and a network of milk ducts, which produce milk and make them ready for the infant to suckle. When a woman becomes pregnant, her body releases the hormone polactin. Prolactin stimulates special breast cells called alveoli to produce milk. This process often causes tenderness and an increase in breast size in pregnant women.
Infants are able to suckle as soon as they are born. In the hours after giving birth, a woman's breasts will produce small amounts of colostrum, a thick yellow liquid that contains large quantities of antibodies and white blood cells. The colostrum helps protect newborns against disease and build up their immunity. It also stimulates the baby's digestive system, helping to produce the first bowel movements, and can reduce bilirubin in babies with jaundice.
As babies nurse, their suckling stimulates the mother's breasts to produce more milk. Three to five days after birth, most mothers' milk begins to be produced regularly in response to the child's demand. The hormone oxytocin contracts the cells around the milk ducts, moving the milk from the glands to the nipples. This process is known as the let-down reflex.
Infants are born with a rooting reflex, which prompts them to seek the breast and try to latch on. Successful breastfeeding depends on an effective latch. To achieve this, the baby's lips should be open wide and close around the areola, taking as much breast tissue into his or her mouth as possible. The baby's pressure on the area around the nipple is necessary to stimulate the production of milk. The more often the baby nurses, the more milk will be produced.
Newborns nurse frequently, often eight to 12 times per day, for 15 to 20 minutes at a time. They consume about 20 to 30 ounces of breast milk each day. Most experts recommend feeding newborns on demand rather than on a fixed schedule. To be sure that infants are getting enough milk, mothers are advised to check that their child is gaining weight on a steady curve after the first week (most babies lose weight in the first days after birth), having frequent bowel movements and wet diapers with clear-colored urine, seems satisfied and content after feedings and leaves the mother's breasts feeling less full or softer after feedings.
With few exceptions, breastfeeding was the only way to nourish young children until the middle of the 19th century. Historically, some aristocratic women employed wet nurses to breastfeed their children, and there were attempts to use milk from cows and goats dating back many centuries. Infant formulas, designed to replace breast milk, were created in the mid-19th century and became popular after World War II. For several generations in the West, women were given medicines at birth to dry up their milk supply. More recently, however, cultural shifts and mounting scientific evidence about the health benefits of nursing have led to a resurgence of the practice. Women in traditional societies typically breastfeed on demand for longer periods of time, up to 3 or 4 years of age.
Breastfeeding is credited with providing many health benefits to both infants and mothers. Babies who breastfeed have lower rates of infection and are thought to be better protected against SIDS (Sudden Infant Death Syndrome). Long-term benefits include reduced rates of obesity, diabetes, cardiovascular disease and allergies among people who were breastfed as babies. Studies have also shown higher intelligence in breastfed children.
For women, breastfeeding helps to reduce the size of the uterus after delivery and control bleeding. It is also thought to help new mothers lose weight. Women who breastfeed exclusively also usually experience lactational amenorrhea, meaning that their menstrual periods are suspended, often for the duration of breastfeeding. While this usually results in a period of infertility, doctors do not recommend lactational amenorrhea as a form of birth control.
Studies have also suggested that breastfeeding reduces women's risk of breast, ovarian and endometrial cancers and protects against heart disease, osteoporosis and rheumatoid arthritis.
Despite the recommendations of the World Health Organization, the American Academy of Pediatrics and breastfeeding support organizations like La Leche League, many women have started to acknowledge difficulties with breastfeeding. Without instruction in latching, letdown, and signs that the baby is eating well, many new mothers report that their experience with breastfeeding is not as natural and enjoyable as they had hoped. In response, many hospitals and midwives now work with lactation consultants who provide instruction and support to new mothers to improve the chances of breastfeeding success.