NCB II- physiologic changes in PG Flashcards
average weight gain in PG? variances?
24-30 lbs for a person of optimal wt
if overweight may gain less
if underweight may gain more
average distribution of wt gain? fetus placenta & amniotic fluid uterine muscle breasts fat blood EC fluid
fetus 7-7.5 lbs placenta and amniotic fluid 4 lbs uterine muscle 2 lbs breasts 3 lbs fat 3 lbs blood 3.3 lbs EC fluid 6.6 lbs
during what weeks does the fetus rapidly gain wt? when does the placenta, blood vol and EC fluid increase progressively vs plateau? when does amniotic fluid peak? when is there the biggest growth in breast tissue?
fetus: 30-40 wks
placenta etc: progressive from 10-32/34 wks, plateaus till 40 wks
amniotic fluid: 35-36 wks
breast tissue: in early PG
uterine size increase is stimulated by what hormone? what happens during the first 20 wks, the 2nd 20 wks?
Estrogen
1st 20 wks: increase in size of uterine muscle
2nd 20 wks: thinning of uterine muscle and increases w/fetal size
what two cervical changes take place during PG?
effacement and dilation
what 3 changes take place in the vaginal vault?
softening
increase in cervical mucous
decrease in pH
what 3 changes take place in breast tissue?
increased pigment in areola
colostrum pre or postnatally
increase in size dt hypertrophy of alveoli
what 4 skin changes can take place and what are the causes of the changes?
chloasma- mb dt folic acid deficiency, can make mom photosensitive
linea nigra darkens- mb dt vit B deficiency
stretch marks- esp w/excessive obesity, some genetic tendency, 50% get and 50% of those will keep them
increased hair growth- starts in 3rd mo dt prolonged growth of hair phase, 2-4 mo PP will get hair loss
2 MS changes?
relaxin softens ligaments to facilitate expansion of pelvic girdle
lumbar lordosis dt increased abd wt
% inc in cardiac outflow? in blood volume? what is increased blood volume dt?
30-40% inc in cardiac output
blood vol increases up to 35% dt increased Na2+ retention, adequate dietary salt and increased synthesis of albumin
4 causes of physiologic edema of PG? what test to do at every visit to check for?
increased capillary P= fluid to tissues
increased capillary permeability
relative Na2+ retention
fetal P in pelvis= decreased venous return from legs= pushes fluid into tissue
monitor at every visit by pretibial edema check
benign ejection systolic heart murmurs are common in PG dt what 3 causes?
increased stroke volume
more rapid ejection of blood from heart
mild anemia
pulse increases by how many beats in PG?
10-15 bpm
what % inc in O2 is needed? split b/w fetus, placenta and maternal metabolism of this increase? % inc in tidal vol? does respiration rate increase?
20% inc, 1/3 for placenta and fetus, 2/3 for maternal metabolism
40% inc in tidal volume
no increase in respiration rate, if see this then might need to think about some other cause than decreased intra-abdominal space
what 5 changes happen in relation to the KDs?
increased urine production
P in bladder increases frequency of urination in 1st and 3rd trimesters
increased Na2+ reabsorption from aldosterone
50% inc in glomerular filtration causes increase in glucose in urine
uterus can compress ureters which can lead to inc risk of UTIs which can lead to premature delivery
what 4 GI changes can take place during PG?
increased dental caries dt inc acidophlilic organisms b/c of hormones of PG
decreased secretion of HCl and pepsin
decreased gastric emptying time and decreased intestinal motility
GB emptying time also increases and can lead to gallstones
what causes decreased gastric emptying time and intestinal motility?
progesterone (relaxation of SM)
can cause bloating and distention
what 4 changes in metabolism take place?
metabolism can inc by 20%
inc thyroid fxn
may be hot and flushed
hyperlipidemia
what happens to triglycerides and chol? fat deposition? what can lack of food cause?
triglycerides and chol can double
more fat deposition for E for fetus and mother
lack of food for 6 hrs can lead to ketonuria
what thyroid hormones inc in PG, which remains unchanged? what decrease? PG increases stress on what blood system?
inc in protein bound T4, unbound T4, free active thyroid remains unchanged
inc in PL, cortisol and aldosterone
dec in GH, FSH, LH
PG adds inc stress to blood glucose system, HPL and E2 creates an insulin-resistant state whereby glucose is shunted from mom to fetus
how much does estrogen inc by? where does it come from? what does it influence growth and fxn in? how does it affects joints and CT? how does it affect skin, KDs, hormone production, mood and insulin?
1000x inc
secreted by ovaries and adrenal cortex
inc growth and fxn of uterus, breasts and labia
inc pliability of CT and inc relaxation of SI jts
inc skin pigmentation
inc Na2+–> therefore retain fluid
stimulates PG production in 3rd trimester
assoc w/mood swings in PG
inc insulin production and secretion and inc tissue sensitivity to insulin
how much does prog inc by? produced where? develops what in the uterus? suppresses what two things? develops what glandular tissue for what? how does it influence fat? changes KD fxn how? effect on SM? effect on insulin? low levels can lead to what? when does it radically decrease?
10x inc produced by corpus luteum and placenta develops decidual cells of endometrium suppresses maternal immunological response to fetus along with contractility of the uterus develops breasts for lactation aids in fat storage increases Na2+ secretion by KDs relaxes SM increases insulin, secretion and sensitivity low levels can cause SAB or prematurity radically decreases at labor onset
PRL inc to what amount at term? produced by what? purpose?
inc to 200 mg/ml at term
produced by maternal and fetal pituitary glands and uterus
sustains milk production and regulates milk consumption and increases bonding
PGs are produced by what? purpose? production itself is stimulated by what hormone?
produced by mother, fetus and placenta
softens cervix and primes maternal body for labor
production stimulated by E
where is oxytocin produced? purpose? what causes its release?
produced by hypothalamus, released by pituitary
stimulates UC, milk let down and ejection
distention of cervix and vagina stimulates release of oxytocin and PGs during labor
where is BHcg secreted from and when does it start? purpose? secretion switches to what layer of the embryo at what time?
secreted by early trophoblast at d 6-8
provides message to corpus luteum that PG has occurred so that it won’t degenerate which means E and P can cont to be secreted
trophoblast layer takes over production 4-6 wks later
HPL is responsible for what? how does it affect hunger? during what state of blood sugar will it be elevated? effect on insulin? when does it plateau and how does this plateau affect the fetus?
responsible for insulin resistance and lipolysis
decreases hunger sensation and diverts maternal carb metabolism to fat metabolism in 3rd trimester
elevated during hypoglycemia (release FFAs for E)
reduces insulin affinity to insulin receptors
plateaus in 3rd trimester w/natural decreasing nutrient delivery to placenta–> good signal for fetus to initiate cortisol and thyroid hormone release to initiate enzyme development for maturation
describe a battledore cord insertion
cord attached at edge of placenta
describe a velamentous insertion
no Wharton’s jelly holding the vessels of the placenta together
risk of cord tearing
normal placenta should have how many vessels? what can an abn be assoc with?
2 arteries, 1 vein
1 artery, 1 vein assoc w/renal or CVD in infant
2 main fxns of placenta
- ‘transfers’ blood from mom to baby, no actual blood transfer but maternal arteries form pools beneath fetal capillaries w/each maternal heartbeat which allows for the delivery of nutrients and O2 to fetus and collection of waste
- secretes hormones to maintain PG: BHcg, HPL, progesterone
besides maintaining PG what is another important fxn of BHcg? what can it be used to determine?
at wks 8-12 it promotes testosterone synthesis and secretion to male sexual differentiation
can be used in dx for quantitative PG tests
when does HPL appear?
how does it work with BHcg? dec HPL can be assoc w/what? inc HPL can be assoc w/what?
HPL appears at the same time as BHcg
works synergistically w/BHcg to maintain PG
dec HPL assoc w/early miscarriage
inc HPL assoc w/hydatidiform moles
what substances are the most difficult to cross the placenta? rapidly absorbed substances? what drugs cross the placenta? outer membrane of placenta destroys what?
ionized substances most difficult to transfer
lipid soluble substances rapidly absorbed
all analgesic, hypnotic and anodynes cross placenta
outer membrane destroys histamine, angiotension, 5HT
what are the 4 mechanisms of transport and some examples for each type? what pathological agents pass well through the placenta?
simple diffusion: O2, CO2, electrolytes
facilitated diffusion via carriers: glucose, most vits, a.a.s
carried on plasma proteins: IgG, RBCs
active transport: water soluble vits, Fe, B vits, Ca2+
viruses, spirochetes, protozoans (toxo and rubella) cross well, most bac don’t
3 fxns of amniotic fluid?
protection
temperature maintenance
allows for fetal movement
define an embryo, what is being formed?
conception (8 wks after conception, 10 wks PG)
major organ system formed at this time
define a fetus, what is being formed?
8 wks after conception to term
differentiation and maturation of tissues
when does fertilization usu occur? implantation?
fertilization: w/in 12 hrs of ovulation
implantation: 7 d after fertilization usu mid posterior area of uterus
