Breastfeeding and Breast Milk

Breastfeeding, also called nursing, is the process of feeding a mother’s breast milk to her infant, either directly from the breast or by expressing (pumping out) the milk from the breast and bottle-feeding it to the infant.

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Overview

Breastfeeding, also called nursing, is the process of feeding a mother’s breast milk to her infant, either directly from the breast or by expressing (pumping out) the milk from the breast and bottle-feeding it to the infant.

Breast milk provides an infant with essential calories, nutrients, and antibodies to protect against some infections.

Breastfeeding is beneficial to both a mother and her infant and offers an important opportunity for the pair to bond.

Mothers who are interested in breastfeeding should discuss it with their healthcare providers both before the baby is born and while in the hospital. Many factors influence successful breastfeeding, including support from healthcare providers, family, community, and the workplace.

Benefits of Breastfeeding

Breastfeeding offers many health benefits for infants and mothers, as well as potential economic and environmental benefits for communities.

Benefits for Infants

For infants, breastfeeding:

Very early skin-to-skin contact and suckling may also have physical and emotional benefits.

Breastfeeding may reduce the risk for certain allergic diseases, asthma, obesity, and type 2 diabetes. It may also help improve an infant’s cognitive development. However, more research is needed to confirm these findings.

Benefits for Mothers

For mothers, breastfeeding:

  • Helps a woman’s body secrete hormones, causing her uterus to contract and heal. These hormones may also postpone the restarting of menstruation, although breastfeeding should not be relied upon to prevent pregnancy
  • Reduces the chance of postpartum depression
  • Enhances mother-infant bonding and can create a sense of accomplishment and satisfaction.
  • May lower risks of developing breast and uterine cancers

Breastfeeding Recommendations

In the United States, the American Academy of Pediatrics (AAP) currently recommends:

  • Infants should be fed breast milk exclusively for the first 6 months after birth; exclusive breastfeeding means that the infant does not receive any additional foods (except vitamin D) or fluids unless medically recommended.
  • Although breastfeeding is the recommended method for feeding infants, and breast milk provides most of the nutrients an infant needs, it does not provide infants with adequate vitamin D. The current recommended daily vitamin D intake for infants and children is available on the American Academy of Pediatrics website.
  • After the first 6 months and until the infant is 1 year old, the mother should continue breastfeeding while gradually introducing solid foods.
  • After 1 year, breastfeeding can be continued if mutually desired by the mother and her infant.

When breast milk is not available, the AAP recommends iron-fortified infant formula as an appropriate alternative during the first year after birth.

Getting Started with Breastfeeding

There are many mothers’ groups, health organizations, and healthcare provider associations that provide very detailed information and support on how to breastfeed. The following overview is provided for information only; it is not meant to take the place of a healthcare provider or lactation consultant’s advice or recommendations.

After an infant is born, the following tips can help with getting started:

  • Breastfeed the infant for the first time as soon as possible after the infant is born.
  • Ask at the hospital whether an on-site lactation consultant is available to assist.
  • Request that the hospital staff do not feed the infant any other food or formula unless it is medically necessary.
  • Allow the infant to stay with the mother throughout the day and night at the hospital so that breastfeeding can happen often.
  • Avoid giving the infant pacifiers or artificial nipples so that the infant gets used to latching on to just the breast.

How to Help an Infant Latch

Infants who are hungry will nuzzle against their mother’s breast and make sucking motions, or they will put their hands in their mouths. The following steps can help with getting an infant to “latch” on to the breast for feeding:

  • Hold the infant against bare chest, dressed in only a diaper to ensure skin-to-skin contact.
  • Keep the infant upright, with his or her head directly under the mother’s chin.
  • Support the infant’s neck and shoulders with one hand and his or her hips with the other hand.
  • Tilt the infant’s head slightly back to make nursing and swallowing easier
  • Allow the breast to hang naturally at first; the infant may open his or her mouth when the nipple is near.
  • As the infant tilts backward, support his or her upper back and shoulders with the palm of the hand and gently pull the infant close.

To break the suction and end a breastfeeding session, a clean finger should be inserted between the breast and the infant’s gums; after a soft pop is heard, the nipple can be pulled out of the infant’s mouth.

A good latch is important for both effective breastfeeding and the mother’s comfort. Signs of a good latch include:

  • The latch feels comfortable and does not hurt or pinch
  • The infant does not need to turn his or her head while feeding, and the infant’s chest is close to the mother’s body
  • Little or no areola, the dark-colored skin surrounding the nipple, is visible
  • The infant’s mouth is filled with breast
  • The infant’s tongue is cupped under the breast
  • The mother can hear or see the infant swallowing
  • The infant’s ears “wiggle” slightly
  • The infant’s lips turn outward, like fish lips, not inward
  • The infant’s chin touches the mother’s breast

Breastfeeding Schedules

Healthy infants will develop their own feeding schedules, and mothers should follow the infant’s cues for when he or she is ready to eat.

The number of times that a mother breastfeeds her infant per day, and the time of day depend on the infant’s age and preference. A newborn will need to be fed eight to 12 times per day, meaning the infant will likely need to breastfeed about every hour or two in the daytime and a couple of times at night during the first few days after birth.

Many newborns will feed for 10 to 15 minutes on each breast. If an infant wants to nurse for a longer period, say 30 minutes or longer on each breast, he or she may not be getting enough milk.

Breastfeeding a Preterm Infant

A preterm infant is an infant who is born before 37 weeks of pregnancy. Breastfeeding is extremely important for a preterm infant. If a child is born preterm, the mother’s milk will be higher in protein and other nutrients than the milk produced by the mother of an infant born at full term.

Some infants who are born preterm may not be able to breastfeed at first, but they do benefit from expressed breast milk. A new mother’s breast milk contains colostrum, which has certain nutrients and immune factors.

Breastfeeding Twins, Triplets, or More

If a mother gives birth to twins or triplets, the benefits of breastfeeding to her and her children are the same as for all mothers and infants. Most mothers can make plenty of milk for twins. Many mothers of triplets or quadruplets can provide enough milk to breastfeed their infants completely or partially.

Traveling with a Breastfeeding Infant

Mothers should always speak with their infant’s healthcare provider before traveling for additional guidance on breastfeeding while traveling. Some things to keep in mind while traveling with an infant include:

  • In extremely hot environments, it is not necessary to supplement a breastfed infant with water, as breast milk contains the right balance of water if feedings happen at regularly spaced intervals consistent with normal feedings
  • Consider taking along a sling or other soft infant carrier to make nursing or carrying the infant easier, particularly if standing for extended periods is needed
  • If planning to be away from the child for an extended period, express and store a supply of breast milk
  • Freshly expressed breast milk is safe for infant consumption for 6 to 8 hours when stored at room temperature
  • Fresh breast milk can be safely stored in a cooler bag with ice packs for up to 24 hours
  • Refrigerated breast milk can be stored for up to 5 days

Returning to Work

National laws in the United States require employers to provide a reasonable break time for an employee to express breast milk for her nursing child for one year after the child’s birth. Employers are also required to provide a place other than a bathroom, shielded from view and free from intrusion, for an employee to express breast milk. Special rooms provided by employers for this purpose are called lactation rooms.

Pumping and Storing Breast Milk

If a mother cannot breastfeed directly, it is important to remove milk during the times she would normally feed the infant. There are three methods for expressing breast milk:

  • Hand expression: Using the hand to manually massage and compress the breast to remove milk
  • Manual pump: Using the hand and wrist to operate a hand-held pumping device that removes milk from the breast
  • Electric breast pump: An electric breast pump that runs on a battery or through an outlet plug and can pump milk from one breast or from both breasts at the same time

Before expressing breast milk, wash your hands thoroughly. Only express milk when you are in a clean area.

Breast milk can be stored in clean glass bottles or hard, BPA-free plastic bottles with tight-fitting lids. After pumping, milk should be refrigerated or frozen immediately, stored in small batches of 2 to 4 ounces.

For refrigeration, storage for as long as 5 to 8 days is acceptable only for very clean expressed milk. Frozen milk is good for 3 to 6 months. After thawing, milk should be used within 24 hours and should not be refrozen because of the risk of contamination.

Nutrition for Breastfeeding Mothers

The increased caloric need for women who are breastfeeding is about 450 to 500 calories per day for those who are not trying to lose weight following pregnancy Whether or not to increase caloric intake during breastfeeding is a decision that should be made with the assistance of a healthcare provider.

Women who are breastfeeding may need additional vitamins and minerals and should talk to a healthcare provider about their specific nutritional needs. Poorly nourished mothers, those on vegan diets or other special diets, and those with certain health conditions may require a supplement of docosahexaenoic acid (DHA) in addition to multivitamins to ensure complete nutrition for breastfeeding.

Common Myths About Breastfeeding

Common myths about breastfeeding can lead to confusion and uncertainty:

Myth: Frequent nursing leads to poor milk production and unsuccessful nursing. 
Fact: Milk supply is best when a healthy infant is breastfed as often as he or she indicates the need.

Myth: Infants get all the milk they need in the first 5 to 10 minutes of breastfeeding. 
Fact: While many older infants can take in most of their milk in the first 5 to 10 minutes, this is not true for all infants. Newborns are not always efficient at nursing and may need longer to feed.

Myth: A breastfeeding mother should space her feedings so that her breasts will have time to refill. 
Fact: A nursing mother’s body is always making milk. If a mother consistently waits until she thinks her breasts have “filled up” before she nurses, her body may respond by reducing total milk production.

Myth: Colostrum (the first milk) is bad for the baby.
Fact: Colostrum is very helpful in promoting a newborn’s health. It contains essential nutrients, provides immune factors, and supports the development of a newborn’s digestive system

Do breastfed infants need other nutrition?

Vitamin D Supplementation

Although breast milk provides most of the nutrients an infant needs, it does not provide infants with adequate vitamin D. Vitamin D is required to prevent rickets, a type of vitamin D deficiency. This disease is rare among breastfed infants but can occur if vitamin supplementation or exposure to sunlight is inadequate.

The current AAP-recommended daily vitamin D intake is 400 IU (International Unit) per day for all infants and children, beginning from the first few days after birth. Human breast milk contains a vitamin D concentration of 25 IU per liter (about 4 cups) or less. Therefore, supplementation is required to meet the 400 IU daily requirement.

Supplementary Feeding

Breastfeeding may be supplemented by feeding an infant expressed breast milk from a bottle, formula, or breast milk from another mother. Supplementation may be needed in certain situations related to the mother or infant.

In the mother:

  • Breast surgery or other trauma
  • Primary breast insufficiency that prevents adequate milk production
  • Physical separation from the infant
  • Serious illness

In the infant:

  • Weight gain insufficient to maintain health (also sometimes called failure to thrive)
  • Cleft lip and/or palate or other abnormality that prevents normal suckling ability
  • Jaundice or liver problems
  • Serious illness or prematurity that requires the infant to be cared for in a special nursery

Breast Milk Banks

Breast milk banks supply fresh breast milk to those who need it. If a mother does not produce enough milk or has an illness that prevents her from feeding her infant, banked milk may be an option. Organizations such as the Human Milk Banking Association of North America can help parents identify milk banks near them or that can ship to the parents’ location. Mothers who produce excess milk their baby does not need can also consider becoming milk donors.

The U.S. Food and Drug Administration (FDA) recommends against feeding an infant breast milk acquired directly from another person or through the internet. If a family decides to use human milk from a source other than the mother, they should ensure that the source has screened its milk donors and taken safety precautions.

Infant Formula

The AAP recommends iron-fortified infant formula as an appropriate alternative during the first year after birth when breast milk is not available. A variety of formulas are sold for infants who are not breastfed or who are partially breastfed. These include:

  • Cow’s milk–based formulas and soy-based formulas, which are fortified with iron
  • Hypoallergenic formulas for those with or at risk for allergic conditions
  • Other formulas designed to meet certain dietary needs, such as galactose-free formulas

The FDA monitors infant formulas to make sure they meet certain standards of nutrition for infants.

Weaning

Weaning is the process of switching an infant’s diet from breast milk or formula to other foods and fluids. In most cases, choosing when to wean is a personal decision that might be influenced by a return to work, the mother’s or infant’s health, or just a feeling that the time is right. Weaning an infant is a gradual process.

The AAP recommends feeding infants only breast milk for the first 6 months after birth. After 6 months, the AAP recommends a combination of solid foods and breast milk until the infant is at least 1 year old. The AAP advises against giving cow’s milk to children younger than 1 year old.

Families should speak with the infant’s healthcare provider before attempting to wean to make sure that he or she is ready for weaning and for complete guidance on weaning.

Complementary Foods

“Complementary feeding” refers to giving a baby solid and liquid foods other than breast milk or infant formula. As babies grow, they have nutritional needs that breast milk or infant formula alone cannot meet. Complementary feeding also supports infants’ jaw and muscle development and helps them develop speech later.

The AAP and the World Health Organization (WHO) recommend introducing safe, nutritious complementary foods into an infant’s diet around 6 months of age. Studies show that introducing complementary foods before 4 months offers little health benefit and can increase the risk of food allergies and choking.

Breastfeeding Risk Factors

In special cases, women may be advised not to breastfeed or will be advised to take steps to ensure their own health while breastfeeding.

Breastfeeding and Medicines

Certain medicines can be dangerous to infants and can pass through breast milk. Women taking the following medicines should speak with their healthcare providers before considering breastfeeding:

  • Antiretroviral medicines (for HIV/AIDS treatment)
  • Birth-control medicines containing estrogen, until breastfeeding has been well established
  • Cancer chemotherapy agents
  • Illegal drugs
  • Certain medicines prescribed to treat migraines, such as ergot alkaloids
  • Mood stabilizers, such as lithium and lamotrigine
  • Sleep-aid medicines

This list is only a guideline. Before breastfeeding, you should speak with your healthcare provider about all medicines that you are taking. These include prescribed medicines, over-the-counter medicines, vitamins, and herbal therapies.

Women who are undergoing radiation therapy should not breastfeed, although some therapies may require only a brief interruption.

Breastfeeding and HIV

In the United States, the AAP and the CDC recommend against breastfeeding if a woman is HIV positive. Without specific interventions to reduce transmission, infants breastfed by mothers with HIV have an increased chance of acquiring HIV through breast milk.

Only HIV-positive mothers living in developing countries should consider breastfeeding their babies, especially if a safe and reliable source of infant formula is unavailable, because breast milk may protect against malnutrition and diarrhea, which are major causes of infant mortality in some areas of the developing world.

If an HIV-positive woman decides to breastfeed her baby, research indicates that the risk of transmitting HIV to her baby can be significantly reduced if she exclusively breastfeeds and if she and her infant take antiretroviral drugs.

Breastfeeding and Other Health Conditions

Flu

Even if the mother has the flu, she should not stop feeding her infant expressed milk. Breast milk remains the recommended source of nutrition for the infant. Breast milk contains antibodies and factors which boost immunity that can help protect infants from flu. Additionally, infants who are breastfed are less vulnerable to infections, including severe lower respiratory illnesses, than infants who are not breastfed. To avoid infecting the infant, someone who is not sick should give the infant the mother's expressed milk.

Zika Virus

If a mother has Zika virus or lives in areas where Zika virus is found, the CDC recommends continuing to breastfeed because current evidence suggests that the benefits of breastfeeding outweigh the risk of Zika virus spreading through breast milk.

Other Infections

If a mother has any of the following conditions, breastfeeding is NOT advised:

  • Infection with human T-cell lymphotropic virus type I or type II
  • Untreated, active tuberculosis

Chronic Conditions

Women with certain chronic illnesses may be advised not to breastfeed or will be advised to take steps to ensure their own health while breastfeeding. For example:

  • Women who have diabetes should monitor their blood sugar levels regularly, may need to reduce their insulin, and may need a snack containing carbohydrates before or during breastfeeding
  • Women who are underweight, including those with thyroid conditions or certain bowel diseases, may need to increase their calories to maintain their own health during breastfeeding
  • Women who have had breast surgery in the past may face some difficulties with breastfeeding
  • Women who actively use drugs or do not control their alcohol intake may be advised not to breastfeed

Galactosemia

Infants who have galactosemia, a rare metabolic disorder in which the body cannot digest the sugar galactose, should not be breastfed.

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Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on Breastfeeding.

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Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH.  

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.  

NIH seeks to understand the aspects of breastfeeding and breast milk that lead to optimal health for mothers and infants.

Some research projects related to breastfeeding and breast milk include:

  • Understanding the full range of benefits from breastfeeding and breast milk for mother and infant and their short-, medium-, and long-term influences on health and disease
  • Examining the social, cultural, and economic impacts of breastfeeding in the United States and worldwide.
  • Studying the nutritional and biochemical components of breast milk and how they might prevent, treat, or reduce the severity of various diseases
  • Identifying nutritional and other components of breast milk that might be lacking and creating strategies to ensure that infants receive these components
  • Understanding the effects of diseases such as malaria, and of chronic conditions such as HIV/AIDS, on breast milk and breastfeeding practices
  • Working together with agencies and organizations to raise awareness of the scientific evidence that breastfeeding recommendations are based on

The BEGIN Project

To better understand human milk, NIH launched the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project. Human milk is a complex biological system with many components and functions. Despite its importance, there is still a lot that is unknown about it. Human milk production should be studied as an interactive system consisting of inputs from the lactating parent, their breastfed baby, and their respective environments to identify components of human milk and understand how they work together. NIH’s research will have important implications for nutritional guidance and interventions to support safe and effective feeding practices.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.