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 O 2 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 blood Fetal vein Fetal artery 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. Mother’s arteries bring fresh blood with oxygen and nutrients to the fetus. Fetal portion of placenta Maternal portion of placenta

Growth and Development During Pregnancy Fetal growth and development Fertilization of an ovum by a sperm Zygote during 1 st 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 weeks Full-term at weeks, avg 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 1 st 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 BifidaNormal Spine Meninges Vertebra Spinal cord Spinal fluid Spine Spina Bifida

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 complications- hypertension, 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 2 Increase in breast size Increase mother's fluid volume 4 Placenta1 1/2 Increase in blood supply to the placenta 4 Amniotic fluid2 Infant at birth7 1/2 Increase in size of uterus and supporting muscles 2 Mother's necessary fat stores 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 hydratedDon’t push yourself. No contact sportsNo exercise on your back Stop if painfulNo bouncy jerky exercise

DODON’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. Don’t exercise while lying on your back after the first trimester of pregnancy or stand motionless for prolonged periods. 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 if you experience any pain, discomfort, or fatigue. Do cool down with 5 to 10 minutes of slow activity and gentle stretching. Don’t participate in activities that may harm the abdomen or involve jerky, bouncy movements. Do drink water before, after, and during exercise. Do eat enough to support the needs of pregnancy plus exercise. Pregnant women can enjoy the benefits of 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 1 st trimester- usual kcal, focus on getting ALL micronutrients 2 nd trimester add 340 kcal/d 3 rd 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 B 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 B 6 pill from weeks sickness-cure.html sickness-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 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 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 (B 6 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, B 6, B 12, 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

Fetal Alcohol Syndrome

Introduction Alcohol readily crosses the placenta Deprives fetus of nutrients and oxygen Fetal alcohol spectrum disorder Fetal alcohol syndrome (FAS) Cluster of physical, mental, and neurobehavioral symptoms Alcohol-related neurodevelopmental disorder (ARND) Alcohol-related birth defects (ARBD)

Introduction Abstinence from alcohol during pregnancy is recommended Severe consequences FAS can only be prevented – not treated Abstinence is recommended for those who may become pregnant

Typical Facial FAS

Drinking During Pregnancy Direct damage Intoxication Indirect damage Malnutrition Alcohol interferes with tissue development during critical periods Fetal blood alcohol concentration (BAC) increase until even with maternal BAC levels

How Much Is Too Much? Even one drink a day may threaten neurological development and behaviors Total alcohol intake Average intakes Drinking patterns Frequency of consumption Quantity consumed Stage of fetal development

When Is the Damage Done? First one to two months of pregnancy Critical periods and alcohol exposure Male alcohol ingestion May affect fertility and fetal development Association with low infant birthweight