Transcript Slide 1
Chapter 15
Nutrition Prior to Pregnancy
Nutrition can affect fertility
Preparation before pregnancy
Achieve and maintain healthy body weight
Choose an adequate and balanced diet
Take a multivitamin for the folate (one of the DGA’s)
Be physically active
Receive regular medical care
Manage chronic conditions
Avoid harmful influences (drugs, tobacco, excess alcohol)
Growth and Development
During Pregnancy
Placental development
Develops in uterus in the early days post-conception
Amniotic sac and umbilical cord
Expelled during childbirth
Interweaving of fetal and maternal blood vessels
delivering O2 and nutrients and carrying out waste
Metabolically active organ:
Yes, it’s an organ
Requires energy and nutrients
Produces hormones that maintain pregnancy and prep for
lactation
The Placenta and
Associated Structures
The arrows indicate the direction of blood flow.
Umbilical cord
Uterine wall
Placenta
Amniotic
sac
In the placenta, maternal
blood vessels lie side by
side with fetal blood vessels
that reach the fetus through
the umbilical cord.
Pool of mother's
Fetal artery
Fetal vein
blood
Fingerlike projections
(called placental villi)
contain fetal blood
vessels and extend
into the pool of
mother’s blood. No
actual mingling of
fetal and maternal
blood occurs, but
substances pass
back and forth.
Umbilical cord
Thus, oxygen and
nutrients from the
mother’s blood enter
fetal vessels, and
waste products are
removed.
Umbilical vein
Umbilical
arteries
Mother’s veins carry
fetal wastes away.
Fetal portion Maternal portion
of placenta
of placenta
Mother’s arteries
bring fresh blood
with oxygen and
nutrients to the fetus.
Growth and Development
During Pregnancy
Fetal growth and development
Fertilization of an ovum by a sperm
Zygote during 1st week
Rapid division to become blastocyst
Implantation in uterine wall
Embryo- 2-8 weeks
1-1/4 inch at 8 weeks: has CNS, CVS, GI tract, fingers,
toes
Fetus- 8-40 weeks
Full-term at 38-42 weeks, avg. 6.5-8 lbs
Stages of Embryonic
and Fetal Development
1) A newly fertilized
ovum is about the size
of a period at the end of
this sentence. This
zygote at less than one
week after fertilization is
not much bigger and
is ready for implantation.
2) After implantation, the
placenta develops and
begins to provide
nourishment to the
developing embryo. An
embryo 5 weeks after
fertilization is about 1 / 2
inch long.
3) A fetus after 11 weeks of
development is just over
an inch long. Notice the
umbilical cord and blood
vessels connecting the
fetus with the placenta.
4) A newborn infant after
nine months of
development measures
close to 20 inches in
length. From 8 weeks to
term, this infant grew 20
times longer and 50 times
heavier.
Growth and Development
During Pregnancy
Critical periods
Times of intense development, rapid cell division
Critical periods occur early in pregnancy
Certain cellular activities can occur only during these times
Adverse influences on organ and tissue development
Each organ has its own critical period
An adverse influence felt
late temporarily impairs
development, but a full
recovery is possible.
Normal
development
An adverse
influence felt early
permanently impairs
development, and a
full recovery never
occurs.
Critical
period
Time
Critical Periods of Development
Growth and Development
During Pregnancy
Neural tube defects – >300,000 births/yr worldwide
1) Anacephaly
Brain either missing or fails to develop
2) Spina bifida
Incomplete closure of spinal cord & its bony encasement
Varying degrees of paralysis → death
Clubfoot, dislocated hip, curved spine, retardation, motor /sensory loss
• - Research on root causes: gene-gene, gene-nutrient, gene-
environment
- Risk factors- family hx, maternal DM or obesity, anti-seizure meds,
mutation in folate-related enzymes
- Folate supplementation 400 µg/d one month prior to conception and
through 1st trimester
- Public health recommendation to “all women of childbearing age”
At 4 weeks, the neural tube has yet to
close (notice the gap at the top).
At 6 weeks, the neural tube (outlined by
the delicate red vertebral arteries) has
successfully closed.
Spina Bifida
Spina Bifida
Normal Spine
Meninges
Vertebra
Spinal cord
Spinal fluid
Spina Bifida
Spine
Spine
Growth and Development
During Pregnancy
Chronic diseases cont’d
Adverse influences at critical times during fetal development
Malnutrition – folate deficiency
Type 2 diabetes
Maternal inadequate nutrition affects cardiovascular growth during
placental & gestational development → infant hypertension, lipid
metabolism, immune system → adult health
Fetal programming
Mother’s nutrition during pregnancy may change gene
expression in fetus, influence disease susceptibility later in life
Maternal Weight
Birthweight is most reliable indicator of infant’s health
Weight prior to conception
Influences fetal growth
Underweight
Higher rates of preterm births and infant deaths
Overweight & obesity
Higher risk of their own medical complicationshypertension, gestational DM, postpartum infections,
Risks for infant- NTD from maternal poor glycemic control,
heart defects and other abnormalities, infant wt >9 lbs from
diabetic mother- caesarean section
Maternal Weight
Weight gain during pregnancy- only 1/3 gain the right
amount; most gain more
Fetal growth and maternal health
Correlates closely with infant birthweight
Predictor of health and development
Recommended weight gains- see the chart
Number of fetuses
Beginning weight
Recommended Weight Gains
Maternal Weight
Weight gain patterns
3.5 pounds in first trimester
1 pound per week thereafter
Large weight gain over short time
Preeclampsia
Components of weight gain
Placenta, uterus, blood, breasts, fluid volume, baby
Maternal fat stores
Weight
gain (lb)
1st trimester
2nd trimester
3rd trimester
Increase in
breast size
2
Increase
mother's
fluid volume
4
Placenta
1 1/2
Increase in
blood supply
to the placenta
4
Amniotic fluid
2
Infant at birth
7 1/2
Increase in size
of uterus and
supporting
muscles
Mother's
necessary
fat stores
2
7
30
Stepped Art
Maternal Weight
Weight loss after pregnancy
Return to prepregnancy weight
Ideal but not typical
Retain a couple of pounds fat with each pregnancy
Seven or more pounds, BMI increased 1 unit risks diabetes and
hypertension
Chronic diseases later in life for mother and infant
Losing the pregnancy weight indicates better success at
maintaining middle age weight
Exercise During Pregnancy
Can continue “moderate intensity” exercise throughout
pregnancy 30 min/session
Do regularly and adjust duration and intensity as needed
“Low-impact” activities like swimming, walking
Benefits
Less diabetes, easier labor
Protect fetal development with Exercise “Don’ts”
Stay out of saunas, hot humid weather.
Keep hydrated
Don’t push yourself.
No contact sports
No exercise on your back
Stop if painful
No bouncy jerky exercise
DO
DON’T
Do begin to
exercise gradually.
Don’t exercise
vigorously after long
periods of inactivity.
Do exercise regularly
(most, if not all, days
of the week).
Don’t exercise in
hot, humid weather.
Do warm up with 5 to 10
minutes of light activity.
Don’t exercise when
sick with fever.
Do 30 minutes or more
of moderate physical
activity; 20 to 60 minutes
of more intense activity
on 3 to 5 days a week will
provide greater benefits.
Don’t exercise while
lying on your back
after the first trimester
of pregnancy or stand
motionless for
prolonged periods.
Pregnant women can enjoy
the benefits of exercise.
Do cool down with 5 to 10
minutes of slow activity
and gentle stretching.
Don’t exercise if you
experience any pain,
discomfort, or fatigue.
Do drink water
before, after, and
during exercise.
Don’t participate in
activities that may
harm the abdomen or
involve jerky, bouncy
movements.
Do eat enough to
support the needs
of pregnancy plus
exercise.
Do rest adequately.
Safe exercise during pregnancy
Energy & Nutrient Needs
During Pregnancy
Nutrient needs tend to be higher than any other time
in life.
To meet needs
Make nutrient-dense selections
Body maximizes absorption, minimizes losses
Fe, folate, Ca especially important
Energy & Nutrient Needs
During Pregnancy
Energy
Increase in basal metabolic rate
1st trimester- usual kcal, focus on getting ALL micronutrients
2nd trimester add 340 kcal/d
3rd trimester add 450 kcal/d
Food energy
Need 15 to 20% more energy than before pregnancy
Nutrient-dense foods
Energy & Nutrient Needs
During Pregnancy
Carbohydrate
Ample carbohydrate is necessary
Protein
RDA – additional 25 grams per day
Essential fatty acids
Omega-3 and omega-6 fatty acids needed for developing
brain material (make a smart baby now)
Energy & Nutrient Needs
During Pregnancy
Fetal blood production and cell growth (DNA)
and maternal red blood cell mass
Folate 600 μg/d
Vitamin B12 2.6 μg/d
Iron 27 mg/d
Zinc 12 mg/d
Benefits of prenatal supplements: Drugstore prenatal OK
Intentionally eat well. The pill can only do so much.
Energy & Nutrient Needs
During Pregnancy
Nutrients for bone development
Protect your own bones from “borrowing”
Vitamin D
Deficiency interferes with calcium metabolism
Calcium
Absorption and retention increase
Intake usually falls below recommendations
Other nutrients
Optimal interval between pregnancies
Vegetarian Diets During
Pregnancy & Lactation
Can support healthy pregnancy and lactation
Must be planned and disciplined
Should include dairy and eggs
Variety of whole foods
Additional supplementation- B12, Fe, Ca, D
Focus on COMPLETE proteins (complementary)
Vegan diets – NO!!
NO!!
NO!!
NO!!!
Risks- too many to list, long-term and irreversible
effects a real potential
Common Nutrition-Related
Concerns of Pregnancy
Nausea
“Morning sickness” to can’t keep anything down
Try a 50 mg B6 pill from weeks 6-14
http://www.morningsicknesshelp.com/morningsickness-cure.html
Constipation and hemorrhoids
Heartburn
Food cravings and aversions
Hormone-induced changes
Nonfood cravings- pica
High-Risk Pregnancies
Infant’s birthweight
Low birthweight (LBW)
5 ½ pounds or less
Risk of complications
Relationship with socioeconomic status
Gestational age
Preterm
Small-for-gestational age
High-Risk Pregnancies
Malnutrition and pregnancy
Fertility
Early, unplanned pregnancy
Poor placental development can affect fetus’s future children
Fetal development
Consequences
Retardation, birth defects, miscarriages, stillbirths, infant
mortality 0-4 yrs.
High-Risk Pregnancies
Food Assistance Programs
WIC
Nutrition education and nutritious foods
Vulnerable populations who qualify for help
Cost-benefit
Remedial and preventive services
High-Risk Pregnancies
Maternal age
Ideal childbearing age 20-25, up to 35 yrs OK
Adolescents
Risk of pregnancy complications
Higher rates of stillbirths, preterm births, and LBW infants
Weight gain recommendations
Imperative need to seek prenatal care
High-Risk Pregnancies
Maternal age
Women older than 35 yrs
Complications often reflect chronic conditions
Cesarean section rates increase
Maternal death rates are higher
Risks for fetus
Down’s syndrome 1/100 for 40 yr old vs. 1/10,000 for 20 yr old
High-Risk Behaviors
Alcohol consumption
Irreversible mental and physical retardation
Fetal alcohol syndrome (FAS)
Medicinal drugs
No medication use without consulting physician
Herbal supplements
Seek physician advice
High-Risk Behaviors
Illicit drugs
Many drugs easily cross the placenta
Impair fetal growth and development
Other risks to fetus, infant, and child
Smoking and chewing tobacco
Harmful effects magnified during pregnancy
Risks for mother and infant
SIDS
High-Risk Behaviors
Exposure to environmental contaminants
Lead
Mercury
Foods to avoid-shark, swordfish, king mackerel, tilefish
Supplements
Foodborne illness
No raw milk or dairy, undercooked eggs, meat or
chicken, no sprouts
Increased risk of listeriosis
Risks associated with illness- meningitis, pneumonia,
miscarriage
High-Risk Behaviors
Vitamin-mineral megadoses
Excessive vitamin A (B6 for morning sickness OK)
Fetal malformations
Caffeine
Miscarriage and fetal death
Fetal growth
Weight-loss dieting
Sugar-substitutes
Short List
Good nutrition and health prior to pregnancy
And prenatal care during pregnancy
Gain a healthy amount of weight
Eat a balanced diet, no risky foods
Regular low-impact exercise
Take prenatal vitamin and mineral supplement
No smoking, drinking, drugs, herbs
Lactation: A Physiological Process
Hormones promote growth and branching of duct
system & milk-producing cells
Prolactin
Milk production
Oxytocin
Cause mammary glands to eject milk into ducts
Let-down reflex
Breastfeeding: A Learned Behavior
Lactation is an automatic, physiological process
Breastfeeding is a learned behavior
Some decide not to breastfeed
La Leche League International- THE experts
Breastfeeding report (p. 28)
Factors influencing breastfeeding and its success
Father
Adequate nutrition and rest
Maternal Energy & Nutrient Needs
During Lactation
Energy intake (~1800 kcal/d total) and exercise
Almost 500 extra kcal per day needed to produce
25 oz milk
Mother can eat 330 kcal extra and let body fat provide
the rest. DGA: Moderate weight loss is OK
Exercise is compatible with breastfeeding
Energy nutrients
Recommendations increase for carbohydrates and fibers
Water
Prevent dehydration
Maternal Energy & Nutrient Needs
During Lactation
Vitamins and minerals
Inadequacies reduce the quantity, not quality of breast
milk
Quality maintained at expense of maternal stores, though this
varies by nutrient
Prolonged inadequate intakes
Impacts several nutrients- calcium, B6, B12, A, D
Supplements
Iron to replete anemia in pregancy
Finish up the bottle of prenatal MVI
Maternal Energy & Nutrient Needs
During Lactation
Food assistance programs
Free formula
Participants are less likely to breastfeed
WIC incentives to encourage breastfeeding
higher priority, longer certification, more foods & quantity,
free breast pump
Particular foods
Strong flavors getting into the milk
Infant w/family history of allergies needs to breastfeed
Maternal Health
HIV infection and AIDS
HIV virus transmissable through breastmilk
Developing countries: Formula made with contaminated
water causes 1.5 million infant deaths/yr
Medications
Diabetes – type I
Postpartum amenorrhea
Does not protect from pregnancy
Breast health
Protective for breast cancer
Practices Incompatible
With Lactation
Alcohol
Easily enters breast milk
Infants eat less when mother consumes alcohol
Medical drugs
Physician consultation
Illicit drugs
Risks
Practices Incompatible
With Lactation
Smoking
Reduces milk volume
Sleep less
Passive smoking and SIDS
Environmental contaminants
DDT, PCBs, and dioxin
Caffeine
Iron bioavailability