Pregnancy physiology Flashcards
Effect of hormone relaxin?
Relaxes all of the joints in the body
* S curve of the spine increases
* Knees are hyperextended
* Flat feet
* Pubic symphysis widens
Why might women get heartburn/reflux
- OS relaxes/loosens
- increased pressure on stomach
In the 3rd trimester the body becomes catabolic
a. true
b. false
a. true
fat stores are broken down quickly
What happens to the blood volume during pregancy
increases by 50-70%
- increased bloodflow
- increased CO
- increased SV
There is increased BMR (basal metabolic rate) during pregnancy
a. true
b. false
a. true
and therefore increased 02 consumption
What happens to CO when pregnant women is laying in a supine position
reduced by 25% (reduce venous return)
if need CPR - do not lay flat -> lateral tilt to move uterus up and across
does plasma volume increase or decrease
increase
does CO increase or decrease
increase
does SV increase or decrease
increase
does total peripheral vascular resistance increase or decrease
decreases
does DBP and SBP increase or decrease?
should decrease until end of pregnancy
how does CO change during labour?
Increases by 10%
extra1/2 litre of blood is pumped into the system with every contraction
stays elevated by 80% in the hour post labour
does RR increase or decrease
increases
does tidal volume increase or decrease
increases
does functional residual capacity increase or decrease
decrease - there is pressure on diaphragm - lifted upwards (less space)
does PC02 increase or decrease
decreases
02 increases
where does 02Hb curve move during pregnancy
to the right - maternal hb is giving up 02 to foetal hb
effect of pregnancy on renal blood flow
60-80% increase in renal plasma flow by the end of second trimester
(GFR increases and creatine clearance increases by 50%)
effect of pregnancy on protein excretion
more protein is excreted due to increased GFR
-> can lead to oedema (80% of women)
why might there be dilatation of the urinary collecting system during pregnancy
progesterone opens tubules, ureters stretch (usually more prononced on right side)
- can present with microscopic haematuria
Effects of increased renal blood flow during pregancy
- increased protein excretion - oedema
- increased glucose excretion (dilatation)
- increased urea and creatine excretion
why might women get a UTI during pregnancy
bladder is not emptying - stasis due to pressure
does urate increase or decrease during pregnancy
increase
What type of anaemia is the most common in pregnant women
iron deficient - there is a 2-3 fold increase in iron
- iron stores go to the foetus
why does RBC and platelet count drop during pregnancy
diluted (increased plasma volume)
there is a 10-20 fold increase in folate requirements during pregnancy
a. true
b. false
a. true
check B12 is normal first
does WCC increase or decrease
increase
why is iron deficiency anaemia common in pregnancy
During pregnancy, the body’s blood volume increases, which means more iron is needed to make more blood to supply oxygen to the baby.
If there isn’t enough iron, iron deficiency anemia can develop.
does d-dimer increase or decrease in pregnancy
increases
*do not used as investigative tool
does alk phos increase or decrease in pregnancy
increase
produced by placenta
does albumin increase or decrease during pregnancy
decrease
total protein decreases
why does iron decrease during pregnancy
The body needs more iron to make hemoglobin, a protein in red blood cells that carries oxygen to the body’s tissues
during pregnancy, the body’s blood volume increases
which means more iron is needed to make more red blood cells
The baby also needs iron for growth and development, which comes from the mother’s stores.
there is increased blood flow to the kidneys
a. true
b. false
a. true
What is the effect of pregnancy on water and salt reabsorption?
salt and water absorption increases due to elevated sex hormone levels
why is glycosuria common
due to increased GFR - and reduced tubular absorption of glucose
What is the effect of pregnancy on protein, glucose, sodium (Na+) and water, creatinine, urea, albumin in urine?
- protein is LOST - proteinuria
- gluocse is LOST - glycosuria
- Na+ is retained/gained
- Water is retained/gained
- Creatinine LOST
- Urea LOST
- Albumin LOST
effect of pregnancy on SV, HR and CO
- SV up by 30%
- HR up by 15%
- CO up by 40%
effect of pregnancy on systolic BP and diastolic BP
- Systolic BP is unaltered
- Diastolic BP is reduced in the 1st/2nd trimester (normal by term)
Effect of pregnancy on venous return
a large foetus can interfere with venous return
-> ankle oedema, supine hypotension, varicose veins
hypotension when lying down on back- uterus interupts venous return
why does SV increase
increased plasma volume
why does TV increase during pregnancy
500ml -> 700ml
due to progesterone - effect on respiratory centre
increased pulmonary ventilation by 40%
oxygen requirements are increased but there is still overbreathing
why might people feel SOB during pregnancy
overbreathing - TV increases
fall in PC02
also - diaphragm elevated due to baby
effect of pregnancy on BMR
increased!! due to thyroxine and adrenocortical hormones
find warm spaces uncomfortable
why might Hb levels fall in pregnancy
- diluted by increased blood volume
- iron deficiency - affects Hb production
effect of pregnancy on coagubility
- hypercoaguble state - increased fibrinogen and facts 7,8,10
- decreased fibronolytic activity -
increased ESR, cholesterol, fibrinogen
risk of thromboembolis
WCC and ESR increased during pregnancy
a. true
b. false
a.true
effect of pregnancy on calcium requirement
calcium requirements increase!! especially 3rd trimester (is actively transported across the placenta)
-> serum calcium and phosphate falls
-> ionised calcium stays the same
what vitamin helps absorb calcium
1,25 hydroxy vitamin D
effects of pregnancy on the liver
hepatic blood flow does not change
ALP raised 50%
albumin levels fall
what are braxton hicks
non-painful practice contractions in late pregnancy
30+ weeks
why might constipation occur?
- mass effect of the baby
- relaxation of smooth muscle (progesterone)
effect of progesterone in pregnancy
relaxes smooth muscle
* reduced BP
* constipation
* ureteral dilation
* bladder dilation
* biliary stasis
* increased TV(lungs expand further)
when does placenta start producing progesterone
starts 6 weeks and takes over from corpus luteum at 12 weeks
progesterone inhibits uterine contractions
a. true
b. false
a. true
by increasing the production of prostaglandins
decreases sensitivity to oxytocin (stimulates development of lobules and alveoli)
effect of estrogen in pregnancy
stimulates growth of myometrium
growth of ductal system in breasts
which cells produce hCG
synchiotrophoblast
when is hCG detected?
9 days after implantation
peaks at 9 weeks
Relaxin - effects?
- supresses myometrium contractions
- relaxes pelvic ligaments
- relaxes pubic symphysis
How is polyspermy prevented
- when the sperm first contacts the egg - it triggers an influx of Na+ into the cells (depolarises the oocyte) - and creates a FAST BLOCK by preventing additional sperm binding - is temporary/not enough
- SLOW BLOCK - release of calcium ions within egg - creates a permanent blockade - stimulates cortical granules in egg periphery to release contents into the perivitelle space (modifys zona pellucida and makes it impenatrable to sperm
what is the fast block
when the sperm first contacts the egg - it triggers an influx of Na+ into the cells (depolarises the oocyte) - and creates a FAST BLOCK by preventing additional sperm binding - is temporary/not enough
what is the slow block
SLOW BLOCK - release of calcium ions within egg - creates a permanent blockade - stimulates cortical granules in egg periphery to release contents into the perivitelle space (modifys zona pellucida and makes it impenatrable to sperm
What do sperm bind to on zona pellucida
ZP3 receptor - this triggers the acrosome reaction
Hydrolytic enzymes digest the zona and create pathway to the ovum plasma membrane
when sperm fuses with ovum is forms a diploid zygote
a. true
b. false
a. true
what is the slow block
sperm stimulate the release of calcium ions
in cortical granules of ovum which inactive ZP3 receptors to prevent polyspermy
when does meiosis 1 begin in oogenesis
in utero - then halted in prophase 1 for years
until menstrual cycle (before ovulation) when primary oocytes re-enter the cell cycle and develop through meosis 1 to become secondary oocytes (begin meosis 2) , held in metaphase 2 of meosis 2 until fertilisation
what phase of the cell cyle are ovum in before puberty
meosis 1 - prophase 1
what phase of the cell cyle are ovum in before fertilisation occurs
meosis 2 - metaphase 2 (seconday oocyte)
how is progesterone used to test for ovulation
day 21 progesterone is tested (luteal phase) - if regular 28-30 day cycle
Sign egg has been released
what structure produces beta hcG
the placenta - signals to corpus luteum to produce more progesterone and estrogen
(synctriotrophoblast cells of placenta) -
hCG can cause nausea and vomiting
safe pain relief for breast feeding mothers?
- paracetamol
- ibuprofen
- dilofenic (or topical)
- dihydrocodeine (short term)
