Lactation refers to the formation of milk in the breasts during the period
. Breastfeeding is the process of the infant obtaining milk by suckling at
, development of mammary function is only completed in pregnancy. During
the first half of pregnancy the mammary ducts proliferate and group
together to form large lobules. During the second half of pregnancy,
secretory activity increases and the alveoli become distended by
accumulating colostrum. After 16 weeks of pregnancy, lactation occurs even
if the pregnancy does not progress.
The ability of the mammary gland to secrete milk during later pregnancy is
called lactogenesis, stage 1. During this time, breast size increases and
fat droplets accumulate in the secretory cells. The onset of copious milk
secretions after birth is lactogenesis, stage 2, and usually occurs from
day two or three to eight days postpartum. During this time, the milk goes
through a maturation process to match the infant's needs. Without
the hormone prolactin, lactation would not occur. During pregnancy
prolactin helps to increase breast mass but does not cause lactation
because it is inhibited by the hormone progesterone, which is made by the
placenta. The inhibiting influence of progesterone is so strong that
lactation is delayed if any of the placenta is retained after birth.
Prolactin levels rise and fall in direct proportion to the frequency,
intensity, and duration of nipple stimulation from the infant's
suckling. During the first week after birth, prolactin levels in
breastfeeding women fall about 50 percent. If a mother does not
prolactin levels usually reach the levels of the nonpregnant state by
seven days postpartum. After milk "comes in" or rapidly
increases in volume, lactation is no longer driven by the hormone
prolactin. It shifts control to a milk removal driven process, i.e.,
sucking stimulus. Thus, the initiation of lactation is not driven by
breastfeeding, but breastfeeding is necessary for the continuation of
The breast is not a passive container of milk. It is an organ that
actively produces milk due to the stimulus of the infant's sucking;
the removal of milk from the breasts causes continued milk production. It
is a supply and demand response that regulates the production of milk to
match the intake of the infant. The composition of breast milk changes to
meet the specific needs of the growing infant. In response to suckling,
the hormone oxytocin causes the milk ejection reflex or
"let-down" reflex to occur. Milk ejection is the forceful
expulsion of milk from the alveoli openings. Oxytocin secretion is also
nature's way of causing a woman's uterus to contract after
birth to control postpartum bleeding and assist in uterine involution.
These contractions can continue for up to 20 minutes after feeding and may
be painful during the first few days. The benefit of this, however, is
that uterine discharge diminishes faster and the uterine involution occurs
Colostrum is thick and creamy yellow as compared with mature milk, which
is thin and bluish-white. Compared with mature milk, colostrum is richer
in protein and
and lower in carbohydrates, fat, and some
. The high concentration of total protein and minerals in colostrum
gradually changes to meet the infant's needs over the first two to
three weeks until lactation is established. The key component in colostrum
and breast milk is immunoglobulins or antibodies that serve to protect the
infant against infections or viruses. Breast milk also facilitates the
development of the infant's own immune system to mature faster. As
a result, breast-fed babies have fewer ear infections,
, and other medical problems than bottle-fed babies. Human milk is rich in
proteins, lipids, carbohydrates, vitamins, minerals, hormones, enzymes,
growth factors, and many types of protective agents. It contains about 10
percent solids for energy and growth and the rest is water, which is
essential to maintain hydration. This is also why a breastfed baby does
not need additional water. Infants can digest breast milk much more
rapidly than formula and, therefore, do not get constipated. On average,
it takes about 30 minutes longer to digest formula as opposed to breast
milk. Breastfed babies have better cheekbone development and better jaw
Besides the benefits of the contracting uterus, the process of producing
milk burns calories, which helps the mother to lose excess weight gained
during pregnancy. After all, that is why pregnant women put on extra fat
during pregnancy—energy storage for milk production. Breastfeeding
is also related to a lower risk of breast
and ovarian cancer. For every year of life spent breastfeeding, a
woman's risk of developing breast cancer drops by 4.3 percent and
this is on top of the 7 percent reduction she enjoys for every baby to
whom she gives birth.
Additionally, there is the convenience. Breast milk is always with the
mother. Mothers do not have to store it. It is always at the right
temperature. It is free. It does not require sterilization. In fact, it
prevents diseases and has protective factors resulting in healthier babies
and decreased healthcare costs. It saves money as there is no need to buy
formula, bottles, and nipples.
It is best to begin breastfeeding immediately after birth as it is an
infant's natural instinct to nurse then. Regardless of the
baby's initial suckling behavior, this interaction stimulates
uterine contractions, promotes colonization of harmless bacteria on the
nipple, and helps to protect the infant from pathogenic bacteria. It is an
important time to nuzzle. Women breastfeed for a longer duration if
feedings are started early. The first several feedings have an imprinting
effect. It is recommended to continue feeding about every two to three
hours. It is important to remember that all babies are different; some
need to nurse almost constantly at first, while others can go much longer
between feedings. There are babies and mothers who have no trouble
breastfeeding, while others may need some assistance. Once the baby begins
to suck, the mother makes sure that the entire dark area around the nipple
(areola) is in the baby's mouth. This helps stimulate milk flow and
allows the baby to get enough milk. Nipple soreness can be a result of the
infant not getting a good grasp of the entire areola. A newborn needs to
be fed at least eight to 12 times in 24 hours. Since breast milk is so
easily digested, a baby may be hungry again as soon as one and one-half
hours after the last feeding.
Mothers need to be comfortable when nursing; therefore, loose,
front-opening clothes and a good nursing bra are essential. They need to
explore different positions for breastfeeding to determine what is best
for them. The cradle hold works well in bed or sitting in a comfortable
chair. The football hold is excellent if the woman had a
. The mother can use pillows to support the baby and a footstool to
(Table by GGS Information Services.)
lap. The mother can position the baby's head by snuggling it in one
arm and supporting her breast with the other hand by keeping her thumb
well above the areola and the rest of the fingers below and under the
breast (sometimes called the C-hold). In this position, the mother can
lift her breast and guide her nipple in any direction as she helps the
baby to take in more of the areola.
For early feedings, the infant should be offered both breasts at each
feeding as this stimulates the need-supply response. The length of the
feeding is up to the mother. The general rule is to watch the baby, not
the clock. If, however, it is a first time mother, 20 to 30 minutes on the
first side can be suggested. If the baby falls asleep at the breast, the
next feeding should begin with the breast that was not nursed. Mothers can
tell if the baby is getting enough milk by checking diapers; a baby who is
wetting between four to six disposable diapers (six to eight cloth) and
who has three or four bowel movements in 24 hours is getting enough milk.
New mothers may experience nursing problems, including the following:
When an infant is properly latched onto the breast, the
baby's nose touches (or nearly touches) the breast. He or she
takes the entire areola into the mouth, facilitating the intake of
milk far back into the throat.
(Illustration by GGS Information Services.)
Lactation consultants work at almost every hospital where babies are
delivered. First-time mothers can request the lactation consultant to
visit her. The mother should make a note of the lactation
consultant's phone number should problems be encountered after
mother and infant go home.
There are no rules about when to stop breastfeeding. A baby needs breast
milk for at least the first year of life and it is preferred that no solid
food be given for at least
the first six months to prevent allergies. As long as a baby eats
age-appropriate solid food, the mother may nurse for several years.
—The tiny air sacs clustered at the ends of the bronchioles in
the lungs in which oxygen-carbon dioxide exchange takes place.
—Also known as Parlodel, it is a dopamine receptor agonist used
to treat galactorrhea by reducing levels of the hormone prolactin and is
also used to treat Parkinson's disease.
—Milk secreted for a few days after birth and characterized by
high protein and antibody content.
—A drug used to prevent or treat migraine headaches. It can cause
vomiting, diarrhea, and convulsions in infants and should not be taken
by women who are nursing.
—The return of a large organ to normal size.
—The initiation of milk secretion.
—A medication prescribed to treat the manic (excited) phases of
—Relating to the breast.
—A drug that interferes with cell growth and is used to treat
rheumatoid arthritis as well as various types of cancer. Side-effects
may include mouth sores, digestive upsets, skin rashes, and hair loss.
Since this drug can supress an infant's immune system, it should
not be taken by nursing mothers.
—The organ that provides oxygen and nutrition from the mother to
the unborn baby during pregnancy. The placenta is attached to the wall
of the uterus and leads to the unborn baby via the umbilical cord.
—The hormone produced by the ovary after ovulation that prepares
the uterine lining for a fertilized egg.
—A hormone that helps the breast prepare for milk production
Behrmann, Barbara L.
The Breastfeeding Café: Mothers Share the Joys, Challenges, and
Secrets of Nursing.
Ann Arbor, MI: University of Michigan Press, 2005.
Hanson, Lars A.
Immunobiology of Human Milk: How Breastfeeding Protects Babies.
Armillo, TX: Pharmasoft Publishing, 2004.
La Leche League International Staff.
The Womanly Art of Breastfeeding.
East Rutherford, NJ: Penguin Group, 2004.
Eating for Two: Recipes for Pregnant and Breastfeeding Women.
Berkeley, CA: Celestial Arts Publishing, 2004.
Olds, Sally, et al.
Maternal-Newborn Nursing & Women's Health Care
, 7th ed. Saddle River, NJ: Prentice Hall, 2004.
Breastfeeding and Human Lactation
, 3rd ed. Boston, MA: Jones and Bartlett Publishers, 2004.
International Lactation Consultants Association.
1500 Sunday Drive, Suite 102; Raleigh, NC 27607. Web site:
La Leche League International.
1400 North Meacham Rd., Schaumburg, IL 60173. Web site:
National Alliance for Breastfeeding Advocacy.
9684 Oak Hill Drive; Ellicott City, MD 21042. Web site: