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