Module 2: Pregnancy III Flashcards

1
Q

when does embryogenesis occur?

A

0 to 8 weeks gestation
first 2 months of pregnancy

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2
Q

embryogenesis overview

A

Egg is fertilized → zygote is formed (within 24 hours of fertilization) → cleavage
woman might not know she is pregnant yet

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3
Q

embryogenesis stages in order

A
  1. cleavage
  2. blastulation
  3. implantation
  4. gastrulation
  5. neurulation
  • growth and development of the fetus
  • 0 to 8 weeks
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4
Q

embryogenesis stage 1: cleavage

A

zygote cleaved into 2 blastomeres

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5
Q

embryogenesis stage 2: blastulation

A

morula divides to form blastocyte (has inner cell mass)

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6
Q

embryogenesis stage 3: implantation

A

6-7 days after fertilization
blastocyte penetrates endometrium
we begin to have a difference between inner cell mass and trophectoderm

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7
Q

embryogenesis stage 4: gastrulation

A

embryo forms blastula (layer of epithelial cells) which reorganizes into gastrula

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8
Q

embryogenesis stage 5: neurulation

A

neural plate turns into neural tube

this will later form brain and spinal cord (CNS)
This allows for organogenesis
Tissues begin differentiated, we get different cell types
Folate is key in neurulation

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9
Q

week 4 major step

A

heart does “practice beatings” (no heartbeat is heard yet)
The practice/testing happens so if things are not working correctly the pregnancy can self-terminate

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10
Q

week 5

A

Week 5: we see more organ systems (still no heartbeat on ultrasound)

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11
Q

which stage has more growth, fetal or embryo?

A

fetal stage

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12
Q

at what week is embryo considered a fetus

A

week 9

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13
Q

when does fetal development occur?

A

8 to 38/40 weeks gestation

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14
Q

why does water decrease in fetus from 30 to 40 weeks

A

increase in fat and protein mass
More deposition of lean body mass, muscles grow and develop
Fat mass is very important to neonatal period
Babies with not enough fat mass end up in the NICU to control their body temperature

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15
Q

fetal development characteristics

A

We see increases in weight with each phase of pregnancy
We see primitive sperm or egg cells
After midway through pregnancy we see calcification of skeleton
Towards end of pregnancy we see deposition of many nutrients
Growth declines a bit near term

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16
Q

critical periods of development

A

finite periods during development in which certain events occur that will have irreversible effects on later developmental stages

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17
Q

key critical periods in fetus

A

during early embryonic period and embryogenesis (much more than fetal period)

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18
Q

critical periods of development overview

A

Differentiation: cellular acquisition of one or more characteristics or functions different from that of the original cell
We make a lot of cells, and then get rid of the ones we don’t need
We want to start with too many rather than two few

19
Q

maternal factors that influence fetal growth

A
  1. micronutrient availability
    - vitamin D
    - antioxidants
  2. inflammation and oxidative stress
  3. vasoconstriction
  4. hormone activity
    - thyroid
    - glucocorticoids
  5. metabolic function
20
Q

placental factors that influence fetal growth

A
  1. implantation
  2. growth
    - mitochondrial function
    - epigenetic regulation
  3. nutrient transfer
    - transporters
    - oxygen gradient
  4. hormone activity
    - placental hormones
    - regulation of hormone transfer
21
Q

fetal growth factors

A
  1. epigenetics
  2. organ toxicity
  3. hormone activity
22
Q

consequences of inadequate nutrition during fetal development

A

small for gestational age (SGA)
large for gestational age (LGA)
intrauterine growth restriction (IUGR)

23
Q

small for gestational age (SGA)

A

newborn weight is <10th percentile for gestational age
dSGA: Normal head size, smaller body and limbs
Proportionally SGA (pSGA): long-term risk factors

24
Q

large for gestation age (LGA)

A

weight for gestational age exceeds the 90th percentile for gestational age or birthweight >4500g

25
variations in fetal growth are linked to
Energy, nutrient, and oxygen availability Conditions that interfere with genetically programmed growth and development Insulin-like growth factor (IGF-1) is the main fetal growth stimulator
26
What effects do preterm birth have on growth and development?
<37 weeks 11.4% of infants born in the US in 2013 were preterm Greater risk of death, neurological problems, and congenital malformations Born without adequate stores of nutrition Infants born preterm are at risk for death, neurological problems, congenital malformations, and chronic health problems
27
preterm birth risk factors
Multivitamin supplements or folate intake decrease risk One to three fish meals per week are protective Underweight and obesity increase risk Elevated blood lipids increase risk
28
What effects do birth weight have on growth and development?
Desirable birth weight: 3500-4500 g (seven pounds and twelve ounces to ten pounds) Less likely to develop heart and lung diseases, diabetes, and hypertension Reduces infant mortality and morbidity
29
what are the only nutrients we don't need more of in pregnancy?
Vit D and calcium BUT, many women are deficient so we must make sure they meet normal levels if not, vit D and caclium can be leached from bones
30
folate deficiency can lead to
neural tube defects
31
folate and neural tube defects
*When neural tube doesn’t close, you end up with neural tube defects Anencephaly: open brain and lack of skull vault Encephalocele: herniation of the meninges (and brain) Spina bifida occulta: closed asymptomatic NTD in which some of the vertebrae are not completely closed
32
folate
Involved in DNA replication Gene expression Amino acid metabolism Recommended intake: RDA for women of child bearing age 400 mcg/day RDA for pregnancy is 600 mcg/day Upper limit is 1000 mcg/day
33
iodine
Neurocognitive development Recommended intake: RDA for women of child bearing age and pregnancy is 220 mcg Upper limit is 1110 mcg
34
choline
Replenish maternal stores Development of brain and spinal cord Recommended intake: RDA for women of child bearing age and pregnancy is 450g
35
iron needs during pregnancy
ron: need increases substantially 300 mg for fetus and placenta 250 mg lost at delivery → need to make sure we have this stored 450 mg for increased red blood cell mass
36
anemia in pregnancy
~23% of pregnant women in developed countries 1 in 10 US pregnancies; 1 in 4 during 3rd trimester Common causes: increased demands, change in dietary patterns, poor nutrition Consequences: compromised growth, cognitive function, and immunity Mortality in mothers and babies Pre-term birth
37
iron function
Fetal hemoglobin has "gamma" which has an increased affinity for oxygen so it will favor it more during the prenatal period (aka in the womb). Adult hemoglobin has the "beta" which has decreased affinity for hemoglobin and is lower in the prenatal period but gets higher in the postnatal period after the baby is born since the fetus takes up so much of the oxygen. Iron can compromise growth, cognitive function, and immunity and leads to mortality and pre-term birth. Need more during pregnancy because of fetal/placental needs and increased RBC mass.
38
iugr
relationship of size and gestational age
39
What is preterm? What are some of the consequences?
< 37 weeks Greater risk of death, neurological problems, and congenital malformations -- also means born without adequate stores of nutrients
40
What is preterm? What are some of the consequences?
< 37 weeks Greater risk of death, neurological problems, and congenital malformations -- also means born without adequate stores of nutrients
41
What are the effects of alcohol use during each trimester?
First trimester Reduce cell growth: in CNS Second trimester Higher risk of miscarriage (in absence of alcohol, miscarriage rate decreases in second trimester) Third trimester Long-term neurological effects Birth defects
42
Describe the characteristic features of fetal alcohol syndrome:
Most severe Abnormal facial features Growth problems CNS abnormalities Problems with social skills, learning, memory, attention span, communication, vision, or hearing
43
Describe the characteristic features of fetal alcohol syndrome:
Most severe Abnormal facial features Growth problems CNS abnormalities Problems with social skills, learning, memory, attention span, communication, vision, or hearing
44
issue with alcohol
Alcohol can cross the placenta. The fetus will have reduced ADH capacity, which increases the harmful effects of alcohol on the fetus. This leads to birth defects, intellectual disability, and developmental disorders.