Life Cycle Nutrition:
Pregnancy and Lactation
Chapter 15

Nutrition Prior to Pregnancy
• Nutrition may affect fertility
• Preparation before pregnancy
– Achieve and maintain healthy body weight
– Choose an adequate and balanced diet
– Be physically active
– Receive regular medical care
– Manage chronic conditions
– Avoid harmful influences

Growth and Development During
Pregnancy
• Placental development
– Develops in uterus
• Amniotic sac and umbilical cord
– Expelled during childbirth
– Interweaving of fetal and maternal blood vessels
– Metabolically active organ
• Requires energy and nutrients
• Produces hormones

Growth and Development During
Pregnancy
• Fetal growth and development
– Fertilization of an ovum by a sperm
– Zygote
• Rapidly divides to become blastocyst
• Implantation
– Embryo
• Eight weeks
– Fetus
• Full-term

Growth and Development During
Pregnancy
• Critical periods
– Times of intense development
• Cellular activities can occur only during these times
– Adverse influences on organ and tissue development

Growth and Development During
Pregnancy
• Neural tube defects
– Anacephaly
• Brain either missing or fails to develop
– Spina bifida
• Incomplete closure of spinal cord & its bony encasement
– Folate supplementation

Growth and Development During
Pregnancy
 Chronic diseases
 Adverse influences at critical times during fetal development
 Malnutrition – type 2 diabetes
 Inadequate growth during placental & gestational development – hypertension
 Fetal programming
 Mother ’ s nutrition may change gene expression in fetus

Maternal Weight
 Birthweight is most reliable indicator of infant ’ s health
 Weight prior to conception
 Influences fetal growth
 Underweight
 Rates of preterm births and infant deaths
 Overweight & obesity
 Medical complications
 Risks for infant

Maternal Weight
• Weight gain during pregnancy
– Fetal growth and maternal health
– Correlates closely with infant birthweight
• Predictor of health and development
– Recommended weight gains

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 Weight
• Weight loss after pregnancy
– Return to prepregnancy weight
• Not typical
– Retain a couple of pounds with each pregnancy
– Seven or more pounds; BMI increase 1 unit

Exercise During Pregnancy
 Can continue exercise throughout pregnancy
 Adjust duration and intensity
 Benefits
 “ Low-impact ” activities
 Fetal development
 Excessively high internal body temperature
 Dehydration

Energy & Nutrient Needs During
Pregnancy
• Needs tend to be higher than any other time in life
• To meet needs
– Make careful selections
– Body maximizes absorption
– Body minimizes losses

Energy & Nutrient Needs During
Pregnancy
• Energy
– Increase in basal metabolic rate
• Second and third trimester
– Food energy
• 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
 Supplements are discouraged
 Essential fatty acids
 Omega-3 and omega-6 fatty acids for brain material

Energy & Nutrient Needs During
Pregnancy
• Blood production and cell growth
– Fetal growth and development
– Maternal red blood cell mass
– Needs for synthesis of DNA and new cells
• Folate
• Vitamin B
12
• Iron
• Zinc

Energy & Nutrient Needs During
Pregnancy
• Nutrients for bone development
– Vitamin D
• Deficiency interferes with calcium metabolism
– Calcium
• Absorption and retention increase
• Intake usually falls below recommendations
– Other nutrients
• Optimal interval between pregnancies

Energy & Nutrient Needs During
Pregnancy
• Prenatal supplements
– Calcium
– Folate
– Iron
• Benefits of use

Vegetarian Diets During Pregnancy
& Lactation
• Can support healthy pregnancy and lactation
– Well planned
– Food sources
• Vegan diets
– Additional supplementation

Common Nutrition-Related
Concerns of Pregnancy
 Nausea
 “ Morning sickness ”
 Hormonal changes
 Constipation and hemorrhoids
 Heartburn
 Food cravings and aversions
 Hormone-induced changes
 Nonfood cravings

High-Risk Pregnancies
 Infant ’ s birthweight
 Low birthweight (LBW)
 5 ½ pounds or less
 Risk of complications
 Relationship with socioeconomic status
 Gestational age

High-Risk Pregnancies
• Malnutrition and pregnancy
– Fertility
• Viable sperm
• Sexual interest
• Amenorrhea
– Early pregnancy
• Placenta development
– Fetal development
• Consequences

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 health
– Preexisting diabetes
• Risks associated with unmanaged diabetes
– Gestational diabetes
• Common consequences
• Dietary recommendations

High-Risk Pregnancies
• Maternal health
– Chronic hypertension
• Risks
– Gestational hypertension
– Preeclampsia
• Cause is unclear
• Risks for mother
• Risks for fetus
– Eclampsia

High-Risk Pregnancies
• Maternal age
– Ideal childbearing age
– Adolescents
• Risk of pregnancy complications
• Higher rates of stillbirths, preterm births, and LBW infants
• Weight gain recommendations
• Need to seek prenatal care

High-Risk Pregnancies
• Maternal age
– Older women
• Complications often reflect chronic conditions
• Cesarean section rates increase
• Maternal death rates are higher
• Risks for fetus

High-Risk Pregnancies
• 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 Pregnancies
• 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 Pregnancies
• Environmental contaminants
– Lead
– Mercury
• Foods to avoid
• Supplements
• Foodborne illness
– Increased risk of listeriosis
– Risks associated with illness

High-Risk Pregnancies
• Vitamin-mineral megadoses
– Excessive vitamin A
• Fetal malformations
• Caffeine
– Miscarriage and fetal death
– Fetal growth
• Weight-loss dieting
• Sugar-substitutes

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

Breastfeeding: A Learned Behavior
• Lactation is an automatic, physiological process
• Breastfeeding is a learned behavior
– Some decide not to breastfeed
• Factors influencing breastfeeding and its success
– Partner
– Adequate nutrition and rest

Maternal Energy & Nutrient Needs
During Lactation
• Energy intake and exercise
– Almost 500 extra kcalories per day
– 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
– Prolonged inadequate intakes
• Impacts several nutrients
• Supplements
– Iron

Maternal Energy & Nutrient Needs
During Lactation
• Food assistance programs
– Participants are less likely to breastfeed
– WIC incentives to encourage breastfeeding
• Particular foods
– Flavors
– Allergies

Maternal Health
 HIV infection and AIDS
 Transmission through breastmilk
 Medications
 Diabetes – type I
 Postpartum amenorrhea
 Does not protect from pregnancy
 Breast health
 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