INTRODUCTION

Human milk is widely recognized as the optimal source of nutrition for all infants. Breast milk promotes development of the infant's immune system and meets the nutritional needs of a full-term infant until approximately six months of age, when complementary foods and fluids are usually added to the diet.

This topic discusses how to prepare to breastfeed, including the benefits of breastfeeding. Additional breastfeeding topics are available separately. (See "Patient information: Common breastfeeding problems (Beyond the Basics)" and "Patient information: Breastfeeding guide (Beyond the Basics)" and "Patient information: Maternal health and nutrition during breastfeeding (Beyond the Basics)" and "Patient information: Breast pumps (Beyond the Basics)".)

SHOULD I BREASTFEED?

Most national and international groups recommend exclusive breastfeeding without the use of infant formula or other foods or liquids for the first six months, and partial breastfeeding for at least 12 months. Despite the overwhelming evidence in favor of breastfeeding, in the United States, only about 74 percent of women breastfeed immediately after birth and only about 43 percent of women are still breastfeeding at six months.

There are many reasons that women choose not to breastfeed, including embarrassment, not understanding the benefits of breast milk, a belief that formula is equal to breast milk, and myths about the "ease" of formula feeding compared to breastfeeding. The benefits of breastfeeding are discussed below. (See 'Benefits of breastfeeding' below.)

Is breastfeeding safe for my child? — Banked human milk or commercial infant formula may be necessary in some situations, such as for infants of women with human immunodeficiency virus (HIV), who are at risk of transmitting their disease through breast milk. In rare cases, a woman's breasts may be incapable of providing a sufficient amount of breast milk. A list of conditions with which breastfeeding is not recommended is available in table 1 (table 1).

BENEFITS OF BREASTFEEDING

There are a number of benefits of breastfeeding, many of which continue even after breastfeeding is discontinued. The benefits for the infant and mother increase as breastfeeding continues. However, even breastfeeding for a short period of time provides some benefits for the infant.

For infants — Some of the benefits of breastfeeding for infants include the following:

• Better digestive tract function and protection from digestive tract infections, such as vomiting and diarrhea.
• A reduced risk of respiratory infections, ear infections, and wheezing.
• Some studies suggest that breastfeeding reduces the risk of obesity, cardiovascular disease, and autoimmune diseases, such as type 1 diabetes mellitus.

For women — Compared with mothers who feed formula, women who breastfeed experience:

• Reduced blood loss after childbirth as a result of a hormone, oxytocin, which is released into the mother's bloodstream while breastfeeding. Oxytocin helps the uterus to contract, which reduces uterine bleeding.
• Reduced levels of stress as a result of several hormones released during breastfeeding.
• Increased weight loss after pregnancy (if breastfeeding continues for at least six months).
• Decreased risk of breast cancer

For family — Families who breastfeed experience:

• Reduced infant feeding costs. Infant formula and associated supplies are estimated to cost at least $1000 during the first 12 months.
• Reduced costs related to healthcare, including doctor's visits, hospital costs, and lost time from work. Infants who are breastfed are less likely to become ill and less likely to be hospitalized, reducing the potential costs and anxieties of caring for an ill child.

BREAST CHANGES AND MILK PRODUCTION

Over the course of a woman's pregnancy, the breasts undergo changes that enable them to produce milk after the baby is born. Most women's breasts enlarge during early pregnancy as the milk producing glands mature (figure 1).

Later in pregnancy, the milk-forming glands fill with a light yellow milk called colostrum. Colostrum contains unique substances that seal and protect the infant's immature digestive tract shortly after birth.

The production of breast milk is triggered by the following:

• Surges in prolactin, stimulated by the infant's suckling at the breast after birth.
• Regular removal of milk from the breast.

Will I make enough milk? — Most women begin to produce large volumes of breast milk by two to three days after delivery, although this can occur as late as seven or more days after delivery. Initial milk production is under hormonal control. All women, whether they choose to breastfeed or not, will experience breast filling.

Continued production of breast milk is dependent upon the breasts being routinely emptied, which then stimulates further production. Most women know their milk is increasing in volume when the breasts become full and firm and sometimes, milk begins to leak spontaneously.

Healthy women who exclusively breastfeed produce approximately 750 to 800 mL (24 to 26 ounces) of milk per day after two to four weeks, when lactation is fully established. However, milk volume varies and can range from 450 to 1200 mL or more (15 to 40 ounces) per day.

Women who are fatigued, ill, stressed, taking certain medications, malnourished, overworked, or who smoke cigarettes may have more difficulty establishing and maintaining a full milk supply. A woman with one or more of these issues is encouraged to seek assistance and support from a lactation consultant, experienced nurse or doctor, or breastfeeding counselor during the first few weeks of breastfeeding.

Breast surgery — Most women are able to produce an adequate amount of milk for their infant. However, breast reduction surgery, and to a lesser degree, breast enlargement surgery, may interfere with a woman's ability to produce an adequate supply of milk.

A decreased ability to produce milk is most likely when an incision is made around the areola or when the nipple has been removed and replaced surgically, which can cut milk ducts, and interrupt nerves and blood flow.

However, having breast surgery does not always mean that a woman will be unable to breastfeed. A woman can attempt breastfeeding while monitoring the infant's weight gain and the number of wet diapers.

PREPARING TO BREASTFEED

Many women who plan to breastfeed wonder about the best way to prepare. A common myth is that women must "toughen" their nipples, although there is no evidence that this is necessary or helpful.

If the nipples are flat or inverted before delivery, it is occasionally difficult for an infant to latch-on. However, there is no benefit to stretching or treating the nipples before delivery. If needed, a lactation consultant or nurse can provide assistance to women with flat or inverted nipples who have breastfeeding challenges after delivery.

Do I need to buy supplies? — It is not necessary to buy any breastfeeding supplies before delivery. Some women choose to purchase a breast pump, although this is not usually needed until the woman returns to work. If a pump is needed sooner (eg, to pump milk for a premature infant), a hospital lactation consultant or nurse can often help to coordinate this. If a lactation consultant or breastfeeding counselor is not available in the hospital, one can often be located by phone or e-mail. (See 'Where to get more information' below and "Patient information: Breast pumps (Beyond the Basics)".).

WHEN TO START NURSING

Breastfeeding should begin within the first few hours of delivery, if possible, by allowing the baby to rest or nurse, skin-to-skin, on the mother's chest. During this time, most infants are alert and interested in nursing. However, there is no evidence that it will be more difficult or impossible to breastfeed if the infant cannot nurse within this time period.

In some situations, the infant or mother must be separated for several hours or even days after delivery. Pumping the breasts and then storing the milk for use is recommended to stimulate the continued production of breast milk; this can be initiated as soon as it is safe, optimally within the first six hours after delivery. A separate topic is available that discusses the use of breast pumps. (See "Patient information: Breast pumps (Beyond the Basics)".)

In the first few days after delivery, the woman produces a small amount of a yellowish milk called colostrum. Colostrum is rich in nutrients and provides all the calories a baby needs for the first few days (see 'Breast changes and milk production' above).

Many women worry that their infant is not getting enough milk immediately after delivery, when only small amounts of colostrum are normally produced. Infants are born with an excess of fluid and sugar stores that they are able to use as the woman's milk supply increases.

It is normal to produce small amounts of milk in the beginning. With continued frequent breastfeeding, a larger amount of mature milk will be produced within two or three days. Infants normally lose weight during the first few days of life and gradually regain this weight by two weeks after delivery.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient information: Deciding to breastfeed (The Basics)
Patient information: Common breastfeeding problems (The Basics)
Patient information: Breast pumps (The Basics)
Patient information: Health and nutrition for women who breastfeed (The Basics)
Patient information: What to expect in the NICU (The Basics)
Patient information: When a baby is born premature (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient information: Common breastfeeding problems (Beyond the Basics)
Patient information: Breastfeeding guide (Beyond the Basics)
Patient information: Maternal health and nutrition during breastfeeding (Beyond the Basics)
Patient information: Breast pumps (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Breastfeeding: Parental education and support
Common problems of breastfeeding and weaning
Infant benefits of breastfeeding
Maternal nutrition during lactation
Nutritional composition of human milk for full-term infants
Postpartum and postabortion contraception
Principles of medication use during lactation
The impact of breastfeeding on the development of allergic disease
Use of psychotropic medications in breastfeeding women
Prevention of HIV transmission during breastfeeding in resource-limited settings

The following organizations also provide reliable health information.

• National Library of Medicine

     (www.nlm.nih.gov/medlineplus/healthtopics.html)

• The Center for Disease Control and Prevention

     (www.cdc.gov/breastfeeding)

• The United States Department of Health and Human Services

     (www.womenshealth.gov/Breastfeeding)

• American Academy of Pediatrics

     (www2.aap.org/healthtopics/breastfeeding.cfm)

• Massachusetts Breastfeeding Coalition

     (www.massbfc.org)

• Breastfeeding On Line

     (www.breastfeedingonline.com)

• Breastfeeding After Reduction (info on breastfeeding after breast/nipple surgery)

     (www.bfar.org)

Finding a lactation consultant — Certified lactation consultants, or LCs, are available at most hospitals as well as privately, and can be an invaluable resource for instructions about breastfeeding, pumping, milk storage, and bottle-feeding breast milk. The websites listed below have information about finding a lactation consultant or breastfeeding counselor.

• La Leche League

     (www.lalecheleague.org)

• International Board of Lactation Consultant Examiners

     (www.iblce.org)

     phone: 703-560-7330

• International Lactation Consultant Association

     (www.ilca.org)

     phone: 919-861-5577

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