Download Perspectives in Nutrition, 8th Edition

Perspectives in Nutrition, 8th Edition
Chapter 16 Outline: Nutritional Aspects of Pregnancy and Breastfeeding
After studying this chapter, you will be able to:
1. Describe factors that predict a successful pregnancy outcome.
2. List major physiological changes that occur in the body during pregnancy and describe how
nutrient needs are altered.
3. Specify the optimal weight gain during pregnancy for adult women.
4. Describe the special nutritional needs of pregnant and lactating women, summarize factors that
put them at risk for nutrient deficiencies, and plan a nutritious diet for them.
5. Identify nutrients that often need to be supplemented during pregnancy and lactation and explain
the reason for each.
6. Discuss potential nutrition-related problems that occur during pregnancy and suggest techniques
for coping with these problems.
7. List substances and practices to avoid during pregnancy and lactation and describe why they are
harmful.
16.1
Pregnancy
A.
General
1.
Gestation: conception to birth, usually 40 weeks
2.
Favorable pregnancy outcome
a.
Live, healthy infant
b.
Full-term gestation period (longer than 37 weeks)
c.
Infant weighs more than 5.5 pounds
d.
Permits the mother to return to her pre-pregnancy status
3.
Preterm birth: before 37 weeks gestation
4.
Low birth weight: weighing less than 5.5 pounds (2500 g)
5.
Small for gestational age: infants suffering from prenatal growth retardation,
weigh less than expected for gestational age
6.
Average weight of a healthy, full-term infant: 7.5 pounds
7.
Complications associated with preterm birth, low birth weight, and/or prenatal
growth retardation
a.
Increased risk of infant death
b.
Medical complications
i.
Handicaps
ii.
Illnesses
iii.
Temperature regulation
iv.
Growth
v.
Development
c.
Nutritional complications
i.
Poor blood glucose control
ii.
Increased nutrient and calorie needs
iii.
B.
C.
Risk of nutrient deficiencies - many nutrient stores are deposited
during last 4 - 6 weeks of gestation
iv.
At risk of developing more body fat and less lean mass during
childhood
Prenatal Developmental Stages: Conception, Zygotic, Embryonic, and Fetal (see Figure
16-4)
1.
Conception: sperm unites with ovum
2.
Zygotic stage: 30 hours after conception - 2 weeks after conception
3.
Embryonic stage: 2 weeks after conception - 8 weeks after conception
a.
By the end of the embryonic stage, the embryo is complex (e.g., major
organs are in place and some have started to function), but only the size
of a pea
4.
Fetal period: 8 weeks after conception - birth
a.
90% of all fetal growth occurs during last 20 weeks of gestation
b.
Average length at birth: 20 - 22 inches
c.
Average weight at birth: 7 - 8 pounds
d.
Body fat is deposited subcutaneously (about 16% by 38 weeks) to help
regulate body temperature
5.
Trimesters: three 13 -14 week periods into which pregnancy is arbitrarily divided
6.
Critical Periods: finite window of opportunity for cells to develop in a particular
organ or tissue
a.
Most occur during first trimester
b.
Nutrient deficiencies, nutrient excesses, pathogens, trauma, radiation,
tobacco smoke, and toxins can interfere with normal development,
resulting in abnormalities or spontaneous abortion
c.
Detrimental prenatal environment can adversely affect development at
any stage of development, but damage is most catastrophic during
critical periods
d.
Some nutrient deficits can be partly reversed by adequate nutrition after
birth
7.
Spontaneous abortion: naturally occurring premature termination of pregnancy
prior to 20 weeks of gestation
a.
Early spontaneous abortions (i.e., miscarriages) usually result from
genetic defect or fatal error in fetal development
b.
Half or more of all pregnancies end in miscarriages, sometimes before
woman knows she is pregnant
c.
15 - 20% more pregnancies end before normal delivery (after 20 weeks
gestation)
Nourishing the Zygote, Embryo, and Fetus
1.
Zygote
a.
Absorbs secretions from uterine glands
b.
Digests some of uterine lining
2.
Embryo
a.
b.
c.
d.
e.
16.2
Placenta delivers nourishment to developing organism through umbilical
cord, which contains 2 arteries and 1 vein to transfer nutrients, oxygen,
and wastes to/from maternal blood supply
Maternal and fetal blood supplies do not mix, but nutrients, oxygen, and
wastes are exchanged by absorption mechanisms similar to GI tract
Placenta synthesizes fatty acids, cholesterol, and glycogen
Placenta produces hormones that regulate fetal metabolism and
physiological changes that support pregnancy in the mother
Placenta’s size and ability to support optimal fetal growth depend on
mother’s nutritional status
Nutrient Needs of Pregnant Women
A.
General
1.
Mother needs to consume more nutrient-dense foods
2.
More efficient use of some nutrients (e.g., protein)
3.
Better absorption of some nutrients (e.g., calcium, iron)
4.
Decreased excretion of some nutrients (e.g., zinc, riboflavin)
B.
Energy Needs
1.
Extra calories support growth of maternal and fetal tissues and extra workload on
mother’s heart, lungs, and other organs
2.
Calorie needs
a.
First trimester: few extra calories above pre-pregnancy needs
b.
Second trimester: 350 extra calories above pre-pregnancy needs
c.
Third trimester: 450 extra calories above pre-pregnancy needs
3.
Estimates of additional calorie needs may vary
a.
Pre-pregnancy weight
b.
Maternal age
c.
Physical activity level
4.
Consequences of calorie restriction during pregnancy
a.
Small for gestational age
b.
Infant mortality
c.
Thrifty metabolism in offspring, which elevates risk of obesity and type
2 diabetes
d.
Greater risk of heart disease, high blood cholesterol, diabetes, high blood
pressure, and impaired immune function in offspring
5.
Iodine
a.
Ensures adequate production of thyroid hormone
b.
Thyroid deficiency during pregnancy can lead to cretinism or other
serious birth defects
c.
Use of iodized salt can prevent deficiency
C.
Nutrients Needed for Building New Cells
1.
Protein
a.
More than 50% above needs of non-pregnant women
2.
3.
4.
b.
In U.S. and Canada, protein intake is plentiful
c.
Protein supplements are unnecessary and not recommended
Essential fatty acids
a.
Required for normal fetal growth and development, particularly of brain
and eyes
b.
Sufficient EFAs, particularly DHA, may improve gestation duration and
infant birth weight, length, and head circumference
c.
Many women need to decrease the ratio of n-6:n-3 fatty acids
d.
Minimize trans fatty acid intake during pregnancy
Zinc
a.
Intake of pregnant and non-pregnant women is often low, but
deficiencies are uncommon
b.
Consequences of severe zinc deficiency
i.
Birth defects
ii.
Fetal growth retardation
iii.
Premature birth
iv.
Spontaneous abortion
v.
Prolonged labor
vi.
Maternal bleeding
vii.
Maternal infections
viii.
Pregnancy-induced hypertension/preeclampsia
c.
Potential causes
i.
Low dietary zinc intake
ii.
High fiber intake
iii.
High iron intake
d.
Factors that impair transfer of zinc from placenta to fetus
i.
Use of certain medications
ii.
Cigarette smoking
iii.
Alcohol abuse
iv.
Strenuous exercise
Folate
a.
Roles during pregnancy
i.
DNA synthesis
ii.
Cell formation (e.g., RBCs)
b.
Consequences of deficiency
i.
Anemia
ii.
Premature birth
iii.
Low birth weight
iv.
Fetal growth retardation
v.
Poor placenta development
vi.
Neural tube defects
vii.
Spontaneous abortion
viii.
Heart defects (1 in 110 newborns)
5.
6.
ix.
Down syndrome
c.
Neural tube defects (see Figure 16-6)
i.
Neural tube develops into brain and spinal cord
ii.
Spina bifida results from incomplete closure of tube during early
gestation; leads to spinal defects, dislocated hips, or other
handicaps
iii.
Anencephaly results from poor brain formation; leads to infant
death
d.
In addition to eating a folate-rich diet, use of multivitamin and mineral
supplement is advised before becoming pregnant to ensure adequate
folate status
e.
History of NTDs may necessitate folic acid supplementation in excess of
RDA; consult health care provider to prevent masking a B-12 deficiency
f.
Folic acid (form in supplements and fortified foods) is absorbed twice as
well as folate that naturally occurs in foods
g.
Fortification of grains with folate has led to17% reduction in NTDs since
1998
Vitamin B-12
a.
Roles during pregnancy
i.
DNA synthesis
ii.
Cell formation
b.
Consequences of deficiency
i.
NTDs
ii.
Anemia
c.
Potential causes for deficiency
i.
Vegetarian diet; requires B-12 supplementation
Iron
a.
Needs rise significantly during pregnancy
b.
Roles of iron during pregnancy
i.
RBC formation (increased maternal supply)
c.
Many women consume insufficient iron and have poor iron status prior
to conception
d.
Maternal adaptations to conserve iron
i.
Absorption increased up to 3 times during pregnancy
ii.
Menstruation ceases
e.
Supplementation
i.
Many experts advise 30 mg/d
ii.
May decrease absorption of zinc and copper
iii.
May decrease appetite
iv.
May cause nausea or constipation
v.
Avoid coffee or tea with supplements to limit polyphenols,
which hinder absorption
vi.
D.
E.
Eat foods rich in vitamin C or heme iron with iron supplements
to enhance absorption
f.
Consequences of deficiency during pregnancy
i.
Suboptimal delivery of oxygen to fetus
ii.
Low birth weight
iii.
Premature birth
iv.
Infant death due to low infant iron stores
v.
Preeclampsia
vi.
Labor and delivery complications
vii.
Increased risk of maternal death
g.
Anemia of pregnancy: normal decrease in ratio of RBCs to total blood
volume due to hemodilution (physiological anemia)
i.
RBCs increase 20 - 30%, whereas blood volume increases 50%
ii.
No danger to health of mother or fetus
Nutrients Needed for Bone and Tooth Development
1.
Calcium
a.
AI does not increase during pregnancy because maternal absorption
efficiency increases
b.
Failure to meet AI puts mother at risk for osteoporosis later in life
because calcium for fetal development is drawn from mother’s bones
regardless of her intake
c.
Populations at risk for calcium deficiency
i.
Vegans
ii.
Pregnant teens
iii.
Women at risk of pregnancy-induced hypertension
iv.
Avoidance of dairy products
d.
Supplementation may be necessary
2.
Vitamin D
a.
Consequences of deficiency for mother
i.
Osteopenia
b.
Consequences of deficiency for fetus
i.
Rickets
ii.
Poor growth
iii.
Inadequate calcification of bones and teeth
c.
Populations at risk for vitamin D deficiency
i.
Avoidance of milk
ii.
Limited exposure to sunlight
d.
Supplementation may be necessary, particularly during winter months in
northern latitudes
Pregnant Women Do Not Have an Instinctive Drive to Consume More Nutrients
1.
Cravings and food aversions are likely due to hormonal changes or family
traditions; no evidence that they result from nutrient deficiencies
2.
3.
4.
16.3
Cravings and aversions won’t affect nutrient status as long as overall diet
provides adequate nutrients and calories
To cope with cravings, eat small amounts of desired foods with regular meals or
snacks; avoid limiting dietary variety
Pica: eating non-food substances (e.g., laundry starch, coal, clay, rubber)
a.
Occurs among men and women in many racial and ethnic groups
b.
Seems to be more of a family tradition than an internal drive
c.
Dangers outweigh potential benefits
i.
Ingestion of toxins
ii.
Intestinal blockages
iii.
Parasites and pathogens
iv.
Malnutrition
v.
Obesity
vi.
Premature birth
vii.
Low birth weight
viii.
Poor fetal nutrient stores
ix.
Maternal and fetal death
Diet and Exercise Plan for Pregnancy
A.
General
1.
Nutrient needs increase more than energy needs, so food choices must be nutrient
dense
2.
MyPyramid eating plans supports successful pregnancy outcome
a.
First trimester
i.
2200 kcal
ii.
Milk: 3 c
iii.
Meat and beans: 6 oz-equivalents
iv.
Vegetables: 3 c; 1 c should be rich in vitamin C and 1 c should
be rich in folate
v.
Fruit: 2 c
vi.
Grains: 7 oz-equivalents; emphasize whole grains
vii.
Oils: 6 t vegetable oil, especially to provide EFAs
viii.
Discretionary calories: up to 300 kcal for weight maintenance
b.
Second and third trimesters
i.
2600 kcal
ii.
Milk: 3 c
iii.
Meat and beans: 6 ½ oz-equivalents
iv.
Vegetables: 3 ½ c
v.
Fruit: 2 c
vi.
Grains: 8 oz-equivalents
vii.
Oils: 7 tsp vegetable oil
viii.
Discretionary calories: up to 400 kcal for gradual weight gain
B.
Prenatal Vitamin and Mineral Supplements
1.
2.
3.
4.
16.4
Routinely prescribed, especially for
a.
Women with a history of frequent dieting
b.
Teenagers
c.
Vegans
d.
Low income
e.
Underweight
f.
Smoke
g.
Abuse of alcohol or illegal drugs
h.
Carrying multiple fetuses
i.
Restricted dietary variety
Over-the-counter or prescription (for high iron or folic acid contents)
Megadoses can be detrimental to maternal and fetal health
a.
Iron
b.
Zinc
c.
Selenium
d.
Vitamin A (teratogenic above 3000 µg/d)
e.
Vitamin B-6
f.
Vitamin C
g.
Vitamin D
Some physicians only prescribe iron supplements during 2nd and 3rd trimesters
and/or individual vitamins or minerals to cover deficiencies (e.g., B-12 for
vegans)
Nutrition-Related Factors Affecting Pregnancy Outcome
A.
Maternal Pre-pregnancy Weight
1.
Pregnancy complications can result when mother is either underweight or
overweight at start of pregnancy
2.
Problems associated with high pre-pregnancy weight
a.
Risks for infant
i.
Increased risk of birth defects
ii.
Increased risk of infant death
iii.
Increased risk of obesity in childhood
b.
Risks for mother
i.
High blood pressure
ii.
Gestational diabetes
iii.
Difficult delivery
3.
Problems associated with low pre-pregnancy weight (BMI < 19.8)
a.
Problems are likely due to lighter placenta and decreased maternal
nutrient stores (especially iron)
b.
Increased risk of low birth weight
c.
Increased risk of premature birth
4.
Pre-pregnancy weight and nutrient stores affect fertility
a.
Underweight may lead to amenorrhea, which reduces ovulation
b.
B.
C.
Low nutrient intakes (e.g., zinc, folate, vitamin C) affect sperm
production
Maternal Weight Gain
1.
Maternal weight gain supports fetal and maternal growth and prepares mother’s
body for lactation (see Figure 16-7)
a.
Maternal fat stores: 4 - 8 lb
b.
Uterus and breasts: 6 lb
c.
Blood: 4 lb
d.
Fetus, placenta, and amniotic fluid: 8 lb
2.
Recommended weight gain for optimal health of both mother and infant based on
pre-pregnancy BMI (see Table 16-4)
a.
Low (BMI <19.8): 28 - 40 lb
b.
Normal (BMI 19.8 - 25.9): 25 - 35 lb
c.
High (BMI 26 -29): 15 - 25 lb
d.
Obese (BMI >29): 15 lb or more
3.
Shorter women, women who were malnourished during childhood, and women
who experienced growth retardation should aim for the lower end of ranges of
weight gain
4.
Adolescents should aim for the upper end of ranges because they tend to deliver
lighter babies than older mothers
5.
Women carrying multiple fetuses should gain more weight
a.
Twins: 35 - 45 lb
b.
Triplets: 50 lb
6.
Although African-American women have increased risk of delivering LBW
infants, there is no current recommendation for them to gain weight at the high
end of ranges
7.
Consequences of gaining too little weight during pregnancy
a.
Premature birth
b.
Small for gestational age
c.
Infant death
8.
Consequences of gaining too much weight during pregnancy
a.
Large babies
b.
Increased delivery complications
c.
Infant mortality
d.
Postpartum maternal weight retention
Pattern of Maternal Weight Gain
1.
First trimester: 2 - 4 lb, accounting for growth of breasts and uterus
2.
Second and third trimesters: ~1 lb/week at a slow, steady rate
a.
Underweight women should gain slightly more
b.
Overweight women should gain slightly less
3.
Low weight gain during 2nd and 3rd trimesters increases chances of fetal growth
retardation
4.
Low weight gain during the 3rd trimester raises risk of premature birth
5.
D.
E.
F.
If weight gain deviates from recommendations, make adjustments to get back on
track (e.g., slow rate of weight gain), but don’t try to lose weight while pregnant
6.
Sudden weight changes during pregnancy may signal health problem (e.g.,
pregnancy-induced hypertension)
Young Maternal Age
1.
Concerns for teen mothers
a.
Physical immaturity: physical maturation continues for 5 years after
menarche (average age of menarche is 13 y)
b.
Teen years demand high nutrient intake, and supporting nutrient needs of
both mother and infant is challenging
c.
Underweight at start of pregnancy, gain too little weight during
pregnancy
d.
Inadequate prenatal care
2.
Risks for infants of teen mothers
a.
Premature birth
b.
Prenatal growth retardation
c.
Infant death
d.
Stillbirth
e.
Spontaneous abortion
Maternal Eating Patterns
1.
Calorie restriction
a.
Ketones are poorly used by fetal brain and may slow its development
b.
Women should consume regular meals and avoid fasting more than 12
hours
c.
Weight loss should never be attempted during pregnancy
d.
Carbohydrate intake should be at least 175 g/d to prevent ketosis
2.
Women with eating disorders, diabetes, or phenylketonuria should work with
health-care providers to ensure diets meet their own and their babies’ needs
3.
Vegan diets: careful planning to ensure adequate protein, vitamin D, vitamin B-6,
iron, calcium, zinc, and vitamin B-12
4.
Use of prenatal multivitamin and mineral supplement helps fill micronutrient
gaps; avoid taking iron and calcium together
Maternal Food Supply
1.
Environmental contaminants
a.
Routes of contamination
i.
Food containers
ii.
Polluted water
iii.
Farming practices
iv.
Food preparation practices
b.
Contaminants of particular concern
i.
Lead: leaded crystal glasses or some dishes, solder on copper
pipes
ii.
Mercury: fish from polluted waterways
iii.
iv.
2.
3.
4.
Polychlorinated biphenyls: fish from polluted waterways
Pesticides: fish from polluted waterways, unwashed fruits and
vegetables
c.
Recommendations
i.
Avoid swordfish, shark, king mackerel, and tilefish
ii.
Limit intake of other fish and shellfish to 12 oz (no more than 6
oz of albacore tuna) per week
iii.
Thoroughly wash fruits and vegetables
Foodborne illness
a.
Pathogens of greatest concern
i.
Listeria monocytogenes can cause spontaneous abortion,
premature delivery, stillbirth, and infections in newborn
ii.
Toxoplasmosis
b.
Foods to avoid
i.
Raw sprouts
ii.
Unpasteurized milk and juices
iii.
Raw or undercooked meat and eggs
iv.
Soft cheeses
c.
Other recommendations
i.
Thoroughly cook leftovers and meats (including processed
meats)
ii.
Avoid litter boxes, kittens, and birds
iii.
Carefully wash produce to remove soil
iv.
Thoroughly cook all meat
Caffeine
a.
Sources
i.
Coffee
ii.
Tea
iii.
Some soft drinks
iv.
Chocolate
v.
Some medications (e.g., headache and cold remedies)
b.
Consequences of intakes >500 mg/d
i.
Reduced fertility
ii.
Increased fetal heart rate
iii.
Decreased blood flow to placenta
iv.
Decreased absorption of certain nutrients (e.g., calcium, iron,
zinc)
v.
Withdrawal symptoms in newborn
c.
Recommendations: limit caffeine consumption to 300 mg/d (~3 c coffee
or 4 c caffeinated soft drinks)
Food additives
a.
Phenylalanine in non-caloric sweeteners can disrupt fetal brain
development for mothers with PKU
G.
Maternal Lifestyle
1.
Women should exercise the most caution while trying to conceive and during the
first trimester
2.
Alcohol
a.
Consequences of alcohol consumption
i.
Impaired fertility
ii.
Displacement of nutrient-dense foods
iii.
Slowed delivery of nutrients and oxygen to embryo or fetus, thus
retarding growth and development
b.
Consequences are most severe during first trimester, but damage can
occur at any time during pregnancy
c.
30/1000 births are affected by alcohol-related defects
d.
Fetal alcohol syndrome
i.
Facial malformations
ii.
Growth retardation
iii.
CNS defects (e.g., mental retardation, small brain size)
e.
Fetal alcohol effects
i.
Learning disabilities
ii.
Short attention span
iii.
Hyperactivity
iv.
Physical birth defects
f.
Alcohol freely crosses the placenta, intensity is magnified by small fetal
size and inability to metabolize alcohol
g.
There is no known safe amount of alcohol consumption during
pregnancy; total abstinence is recommended
3.
Drugs (over-the-counter, prescription, or illegal)
a.
Common culprits
i.
Aspirin
ii.
Hormone ointments
iii.
Nose drops
iv.
Cold medications
v.
Rectal suppositories
vi.
Weight-control pills
vii.
Medications prescribed for previous illnesses
viii.
Marijuana
ix.
Cocaine
x.
Accutane
b.
Consequences
i.
Depleted nutrient stores
ii.
Altered nutrient absorption
iii.
Decreased desire to eat
iv.
Reduced fetal blood flow
v.
Birth defects
4.
5.
16.5
Herbal and botanical products
a.
May exert potent, drug-like effects
b.
All herbal and botanical products should be used with caution under the
guidance of a health-care professional
Nicotine and carbon monoxide
a.
Consequences
i.
Restricted blood flow
ii.
Reduced zinc status, which impairs growth
iii.
Premature birth
iv.
Growth retardation
v.
Birth defects
vi.
Childhood cancer
vii.
Sudden infant death
b.
Other factors that compound the effects of smoking
i.
Low maternal pre-pregnancy weight
ii.
Low weight gain during pregnancy
iii.
Poor maternal diet
Lactation
A.
General
1.
Preparation begins in puberty: hormones stimulate breast development
a.
Fat deposition
b.
Development of lobules and ducts
2.
In early pregnancy, hormones secreted by placenta cause milk-producing glands
to mature and lactiferous ducts to become more branched
3.
Following childbirth, pituitary hormones initiate milk production (prolactin) and
release (oxytoxin)
4.
Without infant suckling, milk production ceases
B.
Milk Production
1.
Birth and infant suckling stimulate manufacture and secretion of prolactin from
pituitary gland
2.
Prolactin stimulates mammary gland to synthesize milk, which promotes milk
production
3.
Lactation must be initiated shortly after birth or milk supply will cease
4.
To establish lactation between mother and infant, sucking should take place
every 2 - 3 hours for 15 - 20 minutes on each breast
5.
Milk production parallels infant demand
a.
Continued suckling stimulates continued lactation, which can be
maintained for years
b.
Women are able to successfully breastfeed twins or triplets
6.
Weaning should be gradual to avoid painful engorgement (e.g., eliminate 1
feeding each week)
7.
Milk Types and Composition
a.
b.
c.
16.6
Colostrum: thin, yellowish, immature milk that appears near the end of
pregnancy or just after birth
i.
Richer in protein, minerals, and vitamin A than mature milk
ii.
Lower in carbohydrate and calories than mature milk
iii.
Contains antibodies and immune system cells that pass through
the infant’s immature GI tract and impart immune defenses
during the first few months of life
iv.
Lactobacillus bifidus factor encourages growth of L. bifidus and
limits growth of potentially toxic bacteria in infant’s GI tract
v.
Laxative effect
Transitional milk: contains more fat, lactose, water-soluble vitamins, and
calories than colostrum
Mature milk
i.
Thin, watery, bluish tinge
ii.
Provides 20 kcal/oz
iii.
Meets all nutrient needs of growing infant, with exceptions of
vitamin D and iron
Nutrient Needs of Breastfeeding Women
A.
General
1.
Nutrient needs and calorie demands of lactation mostly exceed those of
pregnancy
2.
Iron needs are slightly lower than pregnancy and prepregnancy RDAs because
breast milk contains little iron and menstruation is usually delayed for about 6
months
B.
Maternal Nutritional Status
1.
Dietary sources and maternal storage of nutrients keep composition and volume
of milk at consistent levels
2.
Maternal malnutrition must be severe before lactation will cease
3.
Excessive intake of macronutrients and fluids usually have no effect on milk
composition
4.
Proportions of dietary fatty acids may affect milk fat composition
5.
Excessive vitamin or mineral intake may increase mineral content of milk; may
have drug-like effects
6.
Nutrients that are commonly inadequate in diets of lactating women
a.
Calcium
b.
Magnesium
c.
Zinc
d.
Folate
e.
Vitamin B-6
7.
Adequate fluid intake is vital to prevent dehydration: fluid requirements increase
by 32 oz/d (above the 72 oz recommended for non-pregnant women)
8.
Calorie needs for milk production
a.
C.
16.7
Average breastfeeding woman uses 800 kcal/d during the first 6 months
of lactation to produce 750 ml milk/d
b.
400 - 500 kcals/d from dietary sources (following same meal plan as for
2nd and 3rd trimesters) allows for gradual loss of stored fat, especially
when woman continues breastfeeding for 6 months and does some
physical activity
c.
Overweight women can rely entirely on stored fat
d.
Severe calorie restriction that leads to weight loss > 4 lb/month can
decrease milk production
e.
After 6 months of lactation, dietary intake should support calorie needs,
especially if woman has lost pregnancy weight
f.
BMI <18.5 will likely compromise milk production
Food Choices during Lactation
1.
Single food items have little effect on quality or amount of milk production
2.
Some cultures believe that food items (e.g., garlic, beer) increase milk
production, but evidence does not support these beliefs
3.
Fortified breakfast cereal or multivitamin and mineral supplement is advised to
meet nutrient needs
4.
Sufficient omega-3 fatty acids (fish or supplements) are required for secretion in
breast milk to aid in development of infant’s nervous system; follow
recommendations for fish intake set for pregnancy
5.
Avoidance of peanuts or peanut butter may decrease risk of peanut allergy for
infants at high risk for food allergies
Factors Affecting Lactation
A.
General
1.
Benefits for infant
a.
Nutrition
b.
Immunity
c.
Psychology
2.
Benefits for mother
a.
Reduced risk of ovarian and premenopausal breast cancers
b.
Bone remineralization exceeding pre-lactation levels
c.
Weight loss
d.
Quicker return of uterus to pre-pregnancy state
e.
Less postpartum bleeding
f.
Delayed ovulation, leading to decreased chances of pregnancy in the
short term
g.
Reduced risk of metabolic syndrome later in life
B.
Maternal Weight
1.
Obesity may hinder initiation and continuation of breastfeeding
2.
Supplementing human milk with infant formula may be necessary until milk
supply increases
C.
D.
E.
F.
Maternal Age
1.
Infants of adolescent mothers may grow more slowly than infants of older
mothers
2.
Teen mothers may need assistance to meet their own nutritional needs in addition
to those of the infant
Maternal Eating Patterns
1.
Occasional poor dietary intake is no cause for concern
2.
Chronic nutrient and calorie inadequacy may deplete maternal nutrient stores and
negatively affect milk supply
Maternal and Infant Health
1.
Inborn error of metabolism in infant may rule out breastfeeding
a.
PKU
b.
Galactosemia
2.
Infectious diseases may be transmitted through human milk
a.
Tuberculosis
b.
Hepatitis C
3.
Some chronic diseases are incompatible with breastfeeding
a.
Cancer treated with chemotherapy
b.
HIV; however in regions of the world where infectious disease and
malnutrition are primary causes of death, risk of not breastfeeding
outweighs risk of possible transmission of HIV infection
4.
Breast surgery may prevent milk production or secretion
Sociocultural Factors
1.
Breastfeeding is a learned skill; new mothers require:
a.
Education
b.
Social support (including spouse/partner)
c.
Help from knowledgeable health professionals (e.g., lactation
consultants)
2.
Factors that limit breastfeeding success
a.
Lack of information
b.
Lack of confidence
c.
Lack of role models and/or inadequate support system
3.
Sources of accurate breastfeeding knowledge
a.
Lactation consultants
b.
Le Leche League offers classes and information
4.
Facts about breastfeeding
a.
Practically all women are physically capable of breastfeeding
b.
Anatomical problems (e.g., flat or inverted nipples) can be corrected
c.
No relationship between breast size and quality or amount of milk
produced
d.
Women can continue to breastfeed even after returning to work or school
i.
Alternate breastfeeding with bottle feeding
ii.
iii.
iv.
v.
vi.
vii.
G.
H.
Manually express or mechanically pump breast milk into sterile
container; store in refrigerator or freezer
Breastfeeding in public can be done modestly
No state has law prohibiting breastfeeding, but indecent
exposure may be an offense in some states
Infant is receiving adequate milk if the baby has 6+ wet
diapers/d and grows normally
Although ovulation is delayed by breastfeeding, it is no
substitute for reliable birth control
Even premature and/or LBW infants can be breastfed, sometimes
requiring pumping and fortification with certain nutrients (e.g.,
calcium, phosphorus, sodium, and protein)
Maternal Food Supply
1.
Environmental contaminants can appear in milk; effects on infant are unknown
a.
Avoid freshwater fish from polluted waters
b.
Carefully wash and peel fruits and vegetables
c.
Remove fatty portions of meat because contaminants are concentrated in
fat tissue
d.
Avoid rapid weight loss because toxins that have accumulated in fat
tissue may be secreted into breast milk
2.
Local health department has information regarding toxic wastes and other
contaminants
3.
Caffeine may cause irritability, tension, and sleeplessness in infants; avoid
caffeine or limit to 1 - 2 c/d
4.
Some foods impart unpleasant flavors (e.g., cabbage, chocolate); mothers should
pay attention to infants’ behavior
Maternal Lifestyle Choices
1.
Alcohol, drugs, herbal and botanical products, and nicotine are secreted into
breast milk
2.
Although amount in breast milk may be small, dose may be potent for small
infant
3.
Alcohol
a.
Reduces milk output
b.
Causes infants to drink less and have disrupted sleep patterns
c.
Best advice is to avoid alcohol during lactation, but limiting intake and
waiting 3 - 4 hours before nursing are generally safe
d.
Amount of alcohol in breast milk peaks 30 - 60 minutes after ingestion,
then declines
4.
Medications should be used with caution
5.
Illegal drugs (e.g., marijuana, cocaine) should always be avoided
a.
Depress milk production
b.
Transmitted to infant via breast milk, slowing development and causing
vomiting, tremors, breathing difficulties, and convulsions
6.
7.
c.
Drug addicts should not breastfeed their infants
Herbal and botanical products should be used with caution; pass into breast milk
Smoking and secondhand smoke
a.
Lower milk production
b.
Lower infant weight gain
c.
Nicotine can cause vomiting, slow breathing, increased blood pressure,
apathy
d.
Benefits of breastfeeding still outweigh risks of nicotine exposure
16.8
Global Nutrition: Pregnancy and Malnutrition
A.
Effects of undernutrition are profound during pregnancy and fetal life
1.
In Africa, women have 1/20 chance of death from pregnancy (compared to
1/8000 in North America)
2.
Premature birth, low birth weight
a.
Reduced lung function
b.
Weakened immune system
c.
Increased risk of premature death
d.
Growth and developmental problems
B.
Calorie restriction (e.g., 1000 kcal/d) limits fetal growth and development
1.
Famine in Africa
2.
Food shortages during WWII in Holland
3.
Food shortages during siege of Leningrad
16.9
Medical Perspective: Nutrition-Related Physiological Changes of Concern During Pregnancy
A.
Heartburn
1.
Possible causes
a.
Expanding uterus crowds abdominal organs, leading to reflux
b.
Hormones of pregnancy relax lower esophageal sphincter
2.
Recommendations
a.
Eat several small meals
b.
Avoid spicy and fatty foods
c.
Limit caffeine and chocolate
d.
Consume liquids between meals
e.
Wait several hours to lie down after eating
f.
Elevate head of bed
g.
Use of antacids may cause constipation, excessive sodium intake, etc;
consult health-care provider before using them
B.
Constipation
1.
Possible causes
a.
Hormones of pregnancy relax intestinal muscles to slow digestion and
increase nutrient absorption, but increased absorption of water can lead
to hard, dry stools
b.
Growing fetus compresses GI tract
2.
3.
C.
D.
May lead to hemorrhoids
Recommendations
a.
Consume high fiber foods (28 g/d)
b.
Drink more fluids (10 c/d)
c.
Exercise
d.
Adjust dosage of iron supplements
e.
Use of stool softeners and laxatives should be guided by health-care
professional
Nausea and Vomiting
1.
Sometimes called morning sickness, but can occur at any time of day
2.
Potential causes
a.
Increased sense of smell
b.
Iron in prenatal supplements
3.
Recommendations
a.
Breathing cool, fresh air
b.
Avoid offensive odors
c.
Avoid large fluid intakes early in morning
d.
Avoid empty stomach
e.
Eat specific foods that ease symptoms (e.g., starchy, bland foods)
f.
Postponing use of iron-containing supplements until 2nd trimester
4.
Usually eases by 2nd trimester, but 10 - 20% of cases develop into hyperemesis
gravidarium
a.
May lead to dehydration, malnutrition, and electrolyte imbalances
b.
May require medications or hospitalization
Edema
1.
Potential causes
a.
Placental hormones cause fluid retention
b.
Expansion of blood volume
c.
Enlarging uterus compresses blood vessels in the legs (edema in lower
legs is common and expected)
2.
If edema is accompanied by high blood pressure, protein in the urine, or if edema
fails to subside with elevation of feet, this may be a sign of pregnancy-induced
hypertension