Pregnancy Nutrition Flashcards
Define periconceptional (time)
-4 to 4 weeks
Define preterm (time)
less than 37 weeks
Define postterm (time)
more than 42 weeks
Define very preterm (time)
less than 34 weeks
Define term (time)
38-42 weeks
Define embryo (time)
weeks 0-8
Define fetus (time)
weeks 8-40
Define neonatal/neonate/newborn (time)
month 1
Define postneonatal (time)
more than 1 month
Define miscarriage (time)
0-20 weeks
Define fetal death/stillbirth (time)
20-40 weeks
Define perinatal (time)
20 weeks to 7 days post delivery
Define low birthweight
less than 2500g or 5 lb 8 oz
Define very low birthweight
less than 1500g or 3 lb 4 oz
What are natality statistics?
summarize info about:
pregnancy complications and harmful behaviors
infant mortality and morbidity
What type of events lead to declines in infant mortality?
improvements in social circumstances
infectious disease control
availability of safe and nutritious foods
tech advances in medicine (less important)
Define liveborn infant
completely expelled or extracted fetus breathes or shows other signs of life whether or not the cord has been cut
What advantages do newborns weighing 3500-4500 grams have?
least likely to die within first year of life or gestation stages, less likely to develop heart disease, diabetes, lung disease, hypertension and others
What is the difference between gestational age and menstrual age?
gestational age - weeks from conception
menstrual age - weeks from LMP
important difference for calculating nutrition events
What is the sequence of tissue development and approximate week of maximal change?
- maternal plasma volume - 20
- maternal nutrient stores - 20
- placental weight - 31
- uterine blood flow - 37
- fetal weight - 37
What do the physiological changes during the first half of pregnancy do?
“maternal anabolic”
build capacity to deliver blood, oxygen and nutrients
10% of fetal growth
What do the physiological changes during the second half of pregnancy do?
“maternal catabolic”
energy and nutrient stores and capacity to deliver dominate
90% of fetal growth
What changes occur during the maternal metabolic phase?
expanded blood volume, increased cardiac output
buildup of fat, nutrient and liver glycogen stores
growth of some maternal organs
increased appetite and food intake
decreased exercise tolerance
increased levels of anabolic hormones
What changes occur during the maternal catabolic phase?
mobilization of fat and nutrient stores increased production and blood levels of glucose, triglycerides, and fatty acids decreased liver glycogen stores accelerated fasting metabolism increased levels of catabolic hormones increased appetite declines near term
What are some changes related to energy and nutrient needs?
body water changes, hormonal changes, maternal nutrient metabolism
How does the increase in body water impact vitamin status?
dilution effect
blood levels of fat-soluble vitamins tend to increase and water-soluble vitamins tend to decrease
Define placenta
organ of nutrient and gas interchange between mother and fetus
How does CHO metabolism change during pregnancy?
first half - increases in insulin prod. and conversation of glucose to glycogen and fat
second half - inhibit conversion of glucose, increase insulin resistance so she relies more on fats for energy
Why does CHO metabolism change?
promote maternal insulin resistance so there is a continued supply of glucose for the fetus
Why does metabolism change to accelerate fasting?
allows pregnant women to primarily use stored fats for energy so the fetus can use the glucose and amino acids
Define ketones
metabolic by-products of the breakdown of fatty acids in energy formation
Define glucogenic amino acids
amino acids that can be converted to glucose
Why does protein metabolism change?
nitrogen and protein are needed in increasing amounts to synthesis new tissues, this comes from food intake rather than stores
How is the increased need for protein met?
reduced levels of nitrogen excretion
conversion of amino acids
Why does fat metabolism change?
promote the accumulation of maternal fat stores in the first half and enhance fat mobilization in the second half
How does calcium metabolism change?
increased rate of bone turnover and reformation
increased absorption from food
decreased excretion in urine
How does sodium metabolism change?
mother has an increased requirement due to increased body water, needs to accumulate in mother, placenta and fetus
change in kidneys help retain sodium
What are the functions of the placenta?
hormone and enzyme production
nutrient and gas exchange b/t mother and fetus
removal of waste products from fetus
How does nutrient transfer from the placenta occur?
placenta fulfills its needs before supplying the fetus
depends on concentration of nutrients in maternal and fetal blood, molecule size and charge, and lipid solubility
some substances are more regulated than others
What are the mechanisms of nutrient transport across the placenta?
passive diffusion
facilitated diffusion
active transport
endcytosis
What is the difference between growth and development?
growth - increase in size through cell multiplication and enlargement of cells
development - progression of physical and mental capabilities through growth and differentiation of organs and tissues and integration of functions
Define differentiation
cells acquire one or more characteristics or functions different from the original cells
Define critical periods
preprogrammed time periods during embryonic and fetal development when specific things are formed or integrated
Define hyperplasia
increase in cell multiplication
Which organ develops first in humans and gets priority access to nutrients, oxygen and energy?
the brain
followed by heart and adrenal glands
Define hypertrophy
increased size of cells
mainly through accumulation of lipids and protein in cells
What is the sequence of growth and development?
first just hyperplasia, then rate of hyperplasia slows
hyperplasia-hypertrophy phase
hypertrophy only
*specialized functions occur at the same time
maturation - stabilization of cell number and size
What is the general trend of fetal body composition?
progressive increases in fat, protein and mineral content
What is IGF-1?
insulin-like growth factor-1
primary growth stimulator of fetus
promotes uptake of nutrients and inhibits fetal tissue breakdown
levels are sensitive to maternal nutrition
What is IUGR?
intrauterine growth retardation
What can cause reduced fetal growth?
prepregnancy underweight and shortness low weight gain poor diet smoking, drug abuse certain clinical complications
Define SGA
small for gestational age
newborns whose weight is less than the 10th percentile for gestational age
Define dSGA
disproportionately small for gestational age
normal length and head circumference
Define pSGA
proportionately small for gestational age
weight, length and head circumference are all less than 10th percentile for gestational age
Define LGA
large for gestational age
newborns with weights greater than 90th percentile for gestational age
Why does dSGA usually occur?
malnutrition in the third trimester (maternal weight loss or low weight gain late in pregnancy)
compromised liver glycogen and fat storage
compromised energy, nutrient and oxygen availability
What are dSGA infants at risk of?
hypoglycemia, hypocalcemia, hypomagnesiumenia, hypothermia
tend to preform less well in academics
greater risk for heart disease, hypertension, type 2 diabetes
Why does pSGA usually occur?
long-term malnutrition in utero (pre pregnancy underweight, consistently low rate of weight gain, inadequate diet, chronic exposure to alcohol)
What are pSGA infants at risk of?
reduced number of cells
fewer problems at birth, but catch-up growth is poorer
remain shorter and lighter with smaller heads
What might cause LGA?
pre-pregnancy obesity, poorly controlled diabetes, excessive weight gain, other factors
*don’t know for sure
What are maternal complications from LGA babies?
delivery and postpartum increased rates of operative delivery shoulder dystocia (blockage of delivery) postpartum hemorrhage
What nutritional factors are related to an increased risk of miscarriage?
pre-pregnancy underweight
elevated cholesterol, triglycerides, inflammation markers
What are preterm infants at greater risk of?
death, neurological problems, low IQ, congenital malformations, chronic health problems (ex: cerebral palsy)
problems with growth, digestion and respiration
What nutritional factors are related to risk of preterm delivery?
underweight women who gain less than the recommended amount
obese women to a lesser extent
possibly women entering pregnancy with elevated blood lipids, high inflammation markers, and oxidative stress
What is the fetal-origins hypothesis?
theory that exposure to adverse nutritional and other conditions during critical periods can permanently affect body structures and functions and predispose people to certain diseases and disorders
Define developmental plasticity
the concept that development is not strictly determined by genetics, but also by environmental conditions
Define epigenetics
biological mechanisms that change gene function without changing the structure of DNA; they are affected by environmental factors
What are the recommended weight gains for the different weight statuses?
underweight - 28-40 lbs
normal - 25-35 lbs
overweight - 15-25 lbs
obese - 11-20 lbs
What influences birth weight?
maternal weight gain, gestational duration, smoking, maternal health status, gravida, parity
Define gravida
number of pregnancies
Define parity
number of previous deliveries
nulliparous - none
primiparous - one
multiparous - 2+
What is the general pattern of maternal weight gain?
3-5 pounds in the first trimester gradual and consistent after that highest rate is mid-pregnancy rate slows a bit a few weeks prior to delivery *weight should not be lost
What is the composition of weight gain?
only about 1/3 goes to the fetus, the rest goes to maternal tissues and fat stores
Why do energy requirements increase during pregnancy?
increased maternal body mass and fetal growth
increased cardiac and respiratory work; added breast and uterine muscle/tissue; placenta; fetus
How much does energy requirement increase on average?
300 kcal per day
340 kcal/day in the second trimester
452 kcal/day in the third trimester
What are the recommendations for CHO, PRO, and FAT intake?
CHO: 50-60% of kcal, min. 175 g
PRO: 71 g day (25 additional g)
FAT: 13g of linoleic acid; 1.4 g alpha-linolenic acid
What are the effects of alcohol intake during pregnancy?
abnormal mental development and growth
lifelong deficits
Which nutrients are of concern in vegetarian diets?
protein (mainly vegans), B12, D, calcium, iron, zinc, omega-3 fatty acids
What is linoleic acid?
essential fatty acid: omega-6
long chain polyunsaturated fatty acid
sources: safflower, corn, sunflower, soy oil
structural component of cell membranes
What is alpha-linolenic acid?
essential fatty acid: omega-3 (DHA and EPA)
long chain polyunsaturated fatty acid
sources: flaxseed, walnut, soybean, canola, leafy greens
structural component of cell membranes
What are eicosanoids?
synthesized from fatty acids
regulate numerous cell and organ functions
What is EPA?
eicosapentaenoic acid
an omega-3 fatty acid
very important in pregnancy
small amount can be derived from food sources of alpha-linolenic acid
What is DHA?
docosahexaenoic acid
an omega-3 fatty acid
very important in pregnancy
small amount can be derived from food sources of alpha-linolenic acid
What are food sources of EPA and DHA?
fish and seafood - richest sources
egg yolk
fortified eggs and beverages
human milk
What role does EPA play?
reduce inflammation
dilute blood vessels
reduce blood clotting
heart, immune systems
What role does DHA play?
major structural component of phospholipids in cell membranes in the central nervous system
brain, eyes, CNS
How does sufficient intake of EPA and DHA impact birth outcomes?
somewhat higher levels of intelligence
better vision
more mature central nervous system functions
prolong gestation by an average of 4 days
decrease the risk of preterm delivery
What is the recommended intake of EPA and DHA?
250 mg or more per day
don’t exceed 3 g per day
What is the recommendation on fish consumption?
no more than 12oz per week
no more than 6oz per week of albacore tuna
should be ones that are good sources of EPA and DHA and contain low levels of mercury and other contaminants
What types of fish are high in mercury?
swordfish, king mackerel, tilefish, shark
What are the functions of folate?
synthesis of DNA, gene expression, gene regulation, conversion of homocysteine to methionine
What are the risks of high cellular and plasma levels of homocysteine?
increased risk of placenta rupture, stillbirth, preterm delivery, preeclampsia, structural abnormalities, reduced birth weight
Define preeclampsia
increased blood pressure and protein in the urine
results in decreased blood flow to maternal organs and through the placenta
usually occurs after 20 weeks
What are the 3 types of neural tube defects?
- spina bifida - failure of spinal cord to close
- anencephaly - absence of brain or spinal cord
- encephalocele - protrusion of brain through the skull
What is the crucial period for adequate folate availability?
21-27 days after conception
What are food sources of folate?
oranges and orange juice, pineapple juice, papaya juice, dried beans
fortified cereals and grains
What is the recommended intake of folate?
600 mcg of dietary folate equivalent per day
400 from fortified foods or supplements
200 from fruits and vegetables
UL is 1000 mcg per day (so it doesn’t mask the symptoms of B12 deficiency)
What is the role of choline?
component of phospholipids
precursor to intracellular messangers
can be converted to betaine to regulate gene function, neural-tube and brain development, and convert homocysteine to methionine
What is the RDA for choline?
450 mg per day
average intake is low
sources: eggs and meat
What role does vitamin A play?
reactions involved in cell differentiation
What is the impact of vitamin A deficiency early in pregnancy?
malformations of the heart, lungs, and urinary tract
What is the impact of excess vitamin A in the retinol or retinoic acid form?
fetal abnormalities small or no ears abnormal or missing ear canals brain malformation heart defects
What role does vitamin D play?
supports fetal growth, the addition of calcium to bone, and tooth and enamel formation, normal functioning of the immune system and inhibit inflammation
What adverse outcomes are possibly linked to vitamin D deficiency?
miscarriage, preeclampsia, preterm birth, maternal infection, childhood development of type 1 diabetes and asthma
What are risk factors for vitamin D deficiency?
vegan, obese, dark skin, limited exposure to direct sunlight (without sun block), low dietary intake of milk
What is the recommended intake of vitamin D?
5 mcg (200 IU) daily
UL - 50 mcg (2000 IU)
*recommendations are being revised
What is the impact of inadequate calcium intake?
increased blood pressure (mom and infant)
decreased subsequent bone remineralization
decreased breast-milk concentration of Ca
What is the link between calcium and lead?
lead is contained in bone tissue, demineralization of bone to provide calcium also releases lead into the bloodstream
What are the symptoms of iron deficiency?
weakness, fatigue, irritability, short attention span, poor appetite, increased susceptibility to infection
What are the additional symptoms of iron deficiency anemia?
paleness, rapid heart beat, exhaustion
What is the impact of iron deficiency anemia in pregnancy?
increased risk (2-3x) of preterm delivery and low birth weight
What is the impact of iron deficiency in pregnancy?
lower scores on intelligence, language, gross motor, and attention tests
iron deficiency in the infant from inadequate stores at birth
associated with higher maternal mortality
postpartum maternal iron status impacts
What are the recommendations for iron supplementation?
30 mg daily after the 12th week
60-180 mg daily in women with iron deficiency anemia
1/2 of women enter pregnancy with inadequate stores
What is the recommended intake of iron?
an additional 3.7 mg absorbed
total need is 5.5 mg absorbed daily (27 mg)
UL is 45 mg per day consumed
What is the role of iodine?
thyroid function, energy production, fetal brain development
What is the result of iodine deficiency in early pregnancy?
hypothyroidism - growth impairment, mental retardation, deafness
higher incidence of infant mortality
What is the recommended intake of iodine?
220 mcg daily
UL - 1100 mcg daily
salt in processed foods usually isn’t iodized - has been an issue as more processed foods are consumed in developed countries
Define bioactive food components
constituents of foods other than those needed to meet basic human health nutritional needs that are responsible for changes in health status
ex) phytochemicals, antioxidants, caffeine
Who might benefit from multivitamins and mineral supplements?
people with an inadequate diet multifetal pregnancy smoke, drink, or use drugs vegans iron deficiency anemia diagnosed nutrient deficiency
Why are pregnant women more susceptible to food borne illness?
The increased progesterone levels decrease the ability to resist infectious disease
Which food borne illnesses are of greatest concern?
listeria
toxoplasma gondii
What are the possible effects of listeriosis?
spontaneous abortion and stillbirth (1/3)
mild infection in mother
What foods are associated with listeria?
raw or smoked fish, oysters, unpasteurized cheese, raw or undercooked meat, unpasteurized milk
processed meats need to be stored correctly and heated throughly
What can toxoplasma gondii cause?
mental retardation, blindness, seizures, death
What are food sources of T.gondii?
raw and undercooked meats, surface of fruits and vegetables, cat litter
What are the impacts of mercury exposure?
mild to severe effects on brain development
mental retardation, hearing loss, numbness, seizures
accumulates in mothers tissues
What are common health problems during pregnancy?
nausea and vomiting
heartburn
constipation
What is hyperemesis gravidarum?
severe nausea and vomiting lasting through much of the pregnancy, can be debilitating
concerns - weight loss, dehydration, electrolyte imbalance, headache, jaundice
1-2% of pregnancies
may require hospitalization for IV or TPN
What dietary interventions can be used to manage nausea and vomiting?
continue to gain weight separate liquid and solid food intake avoid odors and foods that trigger nausea select foods that are well tolerated supplements - B6, multivitamins, ginger
Why is heartburn common in pregnancy?
progesterone causes the muscles of the gastrointestinal tract to relax so food is more likely to be pushed through the lower esophageal sphincter and into the esophagus
What dietary interventions can be used to manage heartburn?
eat small meals frequently
don’t go to bed with a full stomach
avoid foods that make it worse
antacid tablets are ok
Why is constipation common in pregnancy?
relaxed gastrointestinal muscle tone
What dietary interventions can be used to manage constipation?
consume 30 g of fiber daily
laxatives aren’t recommended
What are inhibitors of iron bioavailability and absorption?
polyphenols, calcium, chlorogenic acid (coffee), phytates
taking it as part of a multivitamin
What are enhancers of iron bioavailability and absorption?
ascorbic acid, alcohol
Why does the US have worse birth outcomes than many other developed countries?
healthcare access
higher c-section rate (elective, litigation)
What are the parts of an APGAR score?
How ready is this child?
heart rate, respiration, irritability, tone, color
What are normal anatomical changes in the first trimester?
pressure on bladdar, lifts later
What are normal anatomical changes in the second trimester?
weight starts shifting back - pushing on spine and causing constipation and low back pain
What are normal anatomical changes in the third trimester?
weight shifting up - presses on stomach - feel full quickly and heartburn, harder to breath
swelling in feet and legs - blood vessels compressed
What is relaxin?
promotes angiogenesis
relaxes ligaments
softens and enlarges the cervix
What is hCS?
human chorionic somatotropin
increases maternal insulin resistance
promotes breakdown of fat for energy
What is hCG?
human chorionic gonadotropin
stimulates CL to produce E and P
stimulates endometrium
What is the distribution of weight gain in a normal pregnancy?
breasts - 1-2 pounds baby - 6-8 pounds placenta - 1-2 pounds uterus - 1-2 pounds amniotic fluid - 2-3 pounds your blood - 3-4 pounds your protein and fat storage - 8-10 pounds your body fluids - 3-4 pounds
Why do energy needs increase during pregnancy and my how much?
increased body mass and fetal growth
only by about 300 kcal per day
3-5 pounds in first trimester, 1-2 pounds/week after that
Why do iron needs increase?
fetal iron requirements
increased RBC mass
compensation for losses at delivery
What is the recommended amount of exercise for most pregnant women?
30 minutes of moderate exercise most or all days of the week
What are the benefits of exercise during pregnancy?
reduce and prevent lower back pain, lower liquid retention, reduced CVS stress and risk of GDM, prevent thrombosis and varicose veins, control weight gain, improve sleep, improve self-esteem, possibly reduce PPD
