Breastfeeding and Lactation

1. Breastfeeding and Lactation

The birth of a child marks the end of pregnancy and the beginning of a new set of responsibilities that includes feeding the newborn. Before the end of pregnancy, a woman needs to consider whether to feed her infant breast milk, infant formula, or both.

did you know

The current rate of breastfeeding is about 80 percent at birth, but then falls to about 50 percent at 6 months, and 30 percent at 1 year. Breastfeeding offers many health benefits to both mother and infant, and every pregnant woman should seriously consider it. Though, in any case, mothers may have valid reasons for not breastfeeding, and formula-fed infants grow and develop into healthy children.

Lactation is a natural process that follows pregnancy as the mammary glands secrete milk for nourishment of the infant. Mammary glands develop in a woman in puberty and remain inactive until pregnancy. During pregnancy, hormones promote the growth and development of milk-producing cells. Hormones play a major role in this, particularly during the second and third trimesters. At that point, levels of the hormone prolactin increase to stimulate the growth of the milk duct system, which initiates and maintains milk production. The hormone oxytocin causes the mammary glands to eject milk into the ducts, a response known as the let-down reflex. The mother may feel this reflex as a contraction of the breast, followed by the flow of milk and the release of pressure. However, levels of the hormone progesterone need to decrease for successful milk production because progesterone inhibits milk secretion. Shortly after birth, the expulsion of the placenta triggers progesterone levels to fall, which activates lactation.

IN CONTEXT

The alveoli cells produce milk. To secrete it, they contract and push milk into the ductules and the milk sinus, which collects the milk. When a nursing infant’s gums press on the areola and nipple, the sinuses squeeze the milk into the baby’s mouth. The nipple tissue becomes firmer with stimulation, which makes it more flexible and easier for the baby to grasp in the mouth.

After the birth of the baby, nutritional needs must be met to ensure that an infant not only survives but thrives from infancy into childhood. Breastfeeding provides the fuel a newborn needs for rapid growth and development. As a result, the World Health Organization (WHO) recommends that breastfeeding be done exclusively for the first six months of an infant’s life.

hint

New mothers must also pay careful consideration to their own nutritional requirements to help their bodies recover in the wake of the pregnancy. This is particularly true for women who breastfeed their babies, which calls for an increased need in certain nutrients.

New mothers need to adjust their caloric and fluid intake to make breastfeeding possible. The RDA is 330 additional calories during the first six months of lactation and 400 additional calories during the second six months of lactation. The energy needed to support breastfeeding comes from both increased intake and from stored fat.

EXAMPLE

During the first six months after her baby is born, the daily caloric cost for a lactating mother is 500 calories, with 330 calories derived from increased intake and 170 calories derived from maternal fat stores. This helps explain why breastfeeding may promote weight loss in new mothers.

Lactating women should also drink 3.1 liters of liquids per day (about 13 cups) to maintain milk production, according to the IOM. An easy guideline to remember is to drink a glass of milk, juice, or water at each meal and each time the infant nurses. As is the case during pregnancy, the RDA of nearly all vitamins and minerals increases for women who are breastfeeding their babies. The following table compares the recommended vitamins and minerals for lactating women to the levels for nonpregnant and pregnant women.

Nutrient	Nonpregnant Women	Pregnant Women	Lactating Women
Vitamin A (mcg)	700.0	770.0	1,300.0
Vitamin (mg)	1.5	1.9	2.0
Vitamin (mcg)	2.4	2.6	2.8
Vitamin C (mg)	75.0	85.0	120.0
Vitamin D (mcg)	5.0	5.0	5.0
Vitamin E (mg)	15.0	15.0	19.0
Calcium (mg)	1,000.0	1,000.0	1,000.0
Folate (mcg)	400.0	600.0	500.0
Iron (mg)	18.0	27.0	9.0
Magnesium (mg)	320.0	360.0	310.0
Niacin () (mg)	14.0	18.0	17.0
Phosphorus	700.0	700.0	700.0
Riboflavin () (mg)	1.1	1.4	1.6
Thiamine () (mg)	1.1	1.4	1.4
Zinc (mg)	8.0	11.0	12.0

Human breast milk not only provides adequate nutrition for infants, it also helps to protect newborns from disease. Breast milk is rich in cholesterol, which is needed for brain development.

key concept

Colostrum is a type of breast milk produced immediately after birth, prior to the start of milk production, and lasts for several days after the arrival of the baby. Colostrum is thicker than breast milk and is yellowish or creamy in color. This protein-rich liquid fulfills an infant’s nutrient needs during those early days. Although low in volume, colostrum is packed with concentrated nutrition for newborns. This special milk is high in fat-soluble vitamins, minerals, and immunoglobulins (antibodies) that pass from the mother to the baby. Immunoglobulins provide passive immunity for the newborn and protect the baby from bacterial and viral diseases.

Two to four days after birth, colostrum is replaced by transitional milk. Transitional milk is a creamy liquid that lasts for approximately two weeks and includes high levels of fat, lactose, and water-soluble vitamins. It also contains more calories than colostrum. After a new mother begins to produce transitional milk, she typically notices a change in the volume and type of liquid secreted and an increase in the weight and size of her breasts.

Mature milk is the final fluid that a new mother produces. In most women, it begins to secrete at the end of the second week post childbirth. There are two types of mature milk that appear during a feeding. Foremilk occurs at the beginning and includes water, vitamins, and protein. Hind-milk occurs after the initial release of milk and contains higher levels of fat, which is necessary for weight gain. Combined, these two types of milk ensure that a baby receives adequate nutrients to grow and develop properly.

IN CONTEXT

About 90 percent of mature milk is water, which helps an infant remain hydrated. The other 10 percent contains carbohydrates, proteins, and fats, which support energy and growth. Similar to cow’s milk, the main carbohydrate of mature breast milk is lactose. Breast milk contains vital fatty acids, such as docosahexaenoic acid (DHA) and arachidonic acid (ARA). In terms of protein, breast milk contains more whey than casein (which is the reverse of cow’s milk). Whey is much easier for infants to digest than casein. Complete protein, which means all of the essential amino acids, is also present in breast milk. Complete protein includes lactoferrin, an iron-gathering compound that helps to absorb iron into an infant’s bloodstream.

In addition, breast milk provides adequate vitamins and minerals. Although absolute amounts of some micronutrients are low, they are more efficiently absorbed by infants. Other essential components include digestive enzymes that help a baby digest the breast milk. Human milk also provides the hormones and growth factors that help a newborn to develop.

big idea

A mother’s diet can have a major impact on milk production and quality. As during pregnancy, lactating mothers should avoid illegal substances and cigarettes. Some legal drugs and herbal products can be harmful as well, so it is helpful to discuss them with your healthcare provider. Some mothers may need to avoid certain things, such as spicy foods, that can produce gas in sensitive infants.

Lactating women can drink alcohol, though they must avoid breastfeeding until the alcohol has completely cleared from their milk. Typically, this takes two to three hours for 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor, depending on a woman’s body weight. Precautions are necessary because exposure to alcohol can disrupt an infant’s sleep schedule.

terms to know

Lactation

A natural process that follows pregnancy as the mammary glands secrete milk for nourishment of the infant.

Oxytocin

A hormone that causes the mammary glands to eject milk into the ducts, a response known as the let-down reflex.

Colostrum

A type of breast milk produced immediately after birth, prior to the start of milk production, and lasts for several days after the arrival of the baby.

Transitional Milk

A creamy liquid that lasts for approximately two weeks and includes high levels of fat, lactose, and water-soluble vitamins. It replaces colostrum two to four days after birth.

Mature Milk

The final fluid that a new mother produces.

Foremilk

Occurs at the beginning of a feeding and includes water, vitamins, and protein.

Hind-milk

Occurs after the initial release of milk and contains higher levels of fat, which is necessary for weight gain.

2. Benefits of Breastfeeding

Breastfeeding has a number of benefits, both for the mother and for the child. Breast milk contains immunoglobulins, enzymes, immune factors, and white blood cells. As a result, breastfeeding boosts the baby’s immune system and lowers the incidence of diarrhea, along with respiratory diseases, gastrointestinal problems, and ear infections. Breastfed babies also are less likely to develop asthma and allergies, and breastfeeding lowers the risk of sudden infant death syndrome. In addition, human milk encourages the growth of healthy bacteria in an infant’s intestinal tract.

did you know

All of these benefits remain in place after an infant has been weaned from breast milk. Some studies suggest other possible long-term effects. For example, breast milk may improve an infant’s intelligence and protect against Type 1 diabetes and obesity, although research is ongoing in these areas.

Breastfeeding has a number of other important benefits.

1. It is easier for babies to digest breast milk than bottle formula, which contains proteins made from cow’s milk that require an adjustment period for infant digestive systems.
2. Breastfed infants are sick less often than bottle-fed infants.
3. Breastfeeding is more sustainable and results in less plastic waste and other trash.
4. Breastfeeding can save families money because it does not incur the same cost as purchasing formula.
5. Breast milk is always ready. It does not have to be mixed, heated, or prepared.
6. Breast milk is sterile and is always at the right temperature.

3. The Baby-Friendly Hospital Initiative

did you know

In 1991, the WHO and UNICEF launched the Baby-Friendly Hospital Initiative (BFHI), which works to ensure that all maternity centers, including hospitals and free-standing facilities, become centers of breastfeeding support.

A maternity center can be denoted as “baby-friendly” when it does not accept substitutes to human breast milk and has implemented ten steps to support breastfeeding.

step by step

These steps include:

1. Having a written policy on breastfeeding communicated to health-care staff on a routine basis.
2. Informing all new mothers about the benefits and management of breastfeeding.
3. Showing new mothers how to breastfeed their infants.
4. Showing new mothers how to maintain lactation.
5. Giving newborns no food or drink other than breast milk, unless medically indicated.

Since the BFHI began, more than fifteen thousand facilities in 134 countries, from Benin to Bangladesh, have been deemed “baby friendly.” As a result, more mothers are breastfeeding their newborns and infant health has improved, in both the developed world and in developing nations.

4. Barriers to Breastfeeding

Although breast milk is ideal for almost all infants, there are some challenges that nursing mothers may face when starting and continuing to breastfeed their infants. These obstacles include painful engorgement or fullness in the breasts, sore and tender nipples, lack of comfort or confidence in public, and lack of accommodation to breastfeed or express milk in the workplace.

IN CONTEXT

One of the first challenges nursing mothers face is learning the correct technique. It may take a little time for a new mother to help her baby properly latch on to her nipples. Improper latching can result in inadequate intake, which could slow growth and development. However, International Board Certified Lactation Consultants (IBCLCs), obstetrical nurses, and registered dietitians are all trained to help new mothers learn the proper technique. Education, the length of maternity leave, and laws to protect public breastfeeding, among other measures, can all help to facilitate breastfeeding for many lactating women and their newborns.

5. Contraindications to Breastfeeding

Although there are numerous benefits to breastfeeding, in some cases there are also risks that must be considered. In the developed world, a new mother with HIV should not breastfeed because the infection can be transmitted through breast milk. These women typically have access to bottle formula that is safe, and can be used as a replacement for breast milk.

key concept

However, in developing nations where HIV infection rates are high and acceptable infant formula can be difficult to come by, many newborns would be deprived of the nutrients they need to develop and grow. Also, inappropriate or contaminated bottle formulas cause 1.5 million infant deaths each year. As a result, the WHO recommends that women infected with HIV in the developing world should nurse their infants while taking antiretroviral medications to lower the risk of transmission.

Women with type 1 diabetes may need careful monitoring and counseling to ensure successful lactation. These women need to adjust their energy intakes and insulin doses to meet the heightened needs of lactation.

Breastfeeding also is not recommended for women undergoing radiation or chemotherapy treatment for cancer. Additionally, if an infant is diagnosed with galactosemia, meaning an inability to process the simple sugar galactose, the child must be on a galactose-free diet, which excludes breast milk. This genetic disorder is a very rare condition, however, and only affects 1 in thirty-to sixty thousand newborns.

hint

When breastfeeding is contraindicated for any reason, feeding a baby formula enables parents and caregivers to meet their newborn’s nutritional needs.

term to know

Galactosemia

An inability to process the simple sugar galactose.

6. Bottle-Feeding

Most women can and should breastfeed when given sufficient education and support. However, a small percentage of women are unable to breastfeed their infants, while others choose not to. For parents who choose to bottle-feed, infant formula provides a balance of nutrients. However, not all formulas are the same, and there are important considerations that parents and caregivers must weigh.

Standard formulas use cow’s milk as a base. They have 20 calories per fluid ounce, similar to breast milk, with vitamins and minerals added. Soy-based formulas are usually given to infants who develop diarrhea, constipation, vomiting, colic, or abdominal pain, or to infants with a cow’s milk protein allergy. Hypoallergenic protein hydrolysate formulas are usually given to infants who are allergic to cow’s milk and soy protein. This type of formula uses hydrolyzed protein, meaning that the protein is broken down into amino acids and small peptides, which makes it easier to digest. Preterm infant formulas are given to low birth weight infants, if breast milk is unavailable. Preterm infant formulas have 24 calories per fluid ounce and are given until the infant reaches a desired weight.

Infant formula comes in three basic types:

1. Powder that requires mixing with water. This is the least expensive type of formula.
2. Concentrates, which are liquids that must be diluted with water. This type is slightly more expensive.
3. Ready-to-use liquids that can be poured directly into bottles. This is the most expensive type of formula. However, it requires the least amount of preparation. Ready-to-use formulas are also convenient for traveling.

IN CONTEXT

Most babies need about 2.5 ounces of formula per pound of body weight each day. Therefore, the average infant should consume about 24 fluid ounces of breast milk or formula per day. When preparing formula, parents and caregivers should carefully follow the safety guidelines since an infant has an immature immune system.

All equipment used in formula preparation should be sterilized. Prepared, unused formula should be refrigerated to prevent bacterial growth. Parents should make sure not to use contaminated water to mix formula in order to prevent foodborne illnesses.

hint

Follow the instructions for powdered and concentrated formula carefully—formula that is overdiluted would not provide adequate calories and protein, while over-concentrated formula provides too much protein and too little water, which can impair kidney function.

It is important to note again that both the American Academy of Pediatrics and the WHO state that breast milk is far superior to infant formula. This table compares the advantages of giving a child breast milk to the disadvantages of using bottle formula.

term to know

Hydrolyzed Protein

Protein that is broken down into amino acids and small peptides.

REFERENCES

American Pregnancy Association. “Breastfeeding versus Bottle Feeding.” November 5, 2012. www.americanpregnancy.org/firstyearoflife/breastfeedingandbottle.html.

Institute of Medicine, www.iom.edu.