8.2 Maternal physiology & pregnancy Flashcards
(31 cards)
‘normal’ acid-base balance in pregnancy. why?
respiratory alkalosis, compensated by renal bicarb excretion
due to increased minute volume and tidal volume = hyperventilation so low co2
why might dyspnoea of pregnancy occur?
decreased PaCO2, and a contribution from hyperventilation
2 ways the CVS is adapted
- volume expansion
- clotting
explain volume expansion of the CVS
early- increased volume
late- increased HR
progesterone relaxes smooth muscle and drops BP
explain clotting of CVS
increased procoagulants
decreased anticoagulants
reduced fibrinolysis
how is SV increased? consequences?
oestrogen and progesterone activate RAAS
-can result in oedema due to fluid retention
-dilutional anaemia
dilution anaemia
not enough RBCs made for the increase in plasma volume, even though RBCs would be bigger
consequence of clotting being upregulated
hypercoagulable state so could increase thrombolic events
commonest cause of anaemia in pregnancy
iro deficiency
why do serum urea and creatinine drop?
GFR increases so more is cleared and excreted
cause of glucosuria
decreased PCT absorption
why can pregnancy increase risk of UTIs
decreased speed of passage of urine due to smooth muscle relaxation (ureters)
overall change to GI system
slow transit time
which LFT raised? why?
ALP due to placental synthesis
can goitre be normal in pregnancy?
yes due to thyroid stimulation
why are T3 and 4 levels raised?
oestrogen stimulates thyroxine binding globulin so need to increase thyroxine
risk factors for gestational diabetes
-BMI >30
-previous macrosomic baby weighing >4.5kg
-family history of diabetes
-ethnicity with high diabetes prevalence
investigations for gestational diabetes
oral glucose tolerance test for those with risk factors
blood glucose
diagnosis of gestational diabetes
fasting plasma glucose 5.6 or above
2 hour plasma glucose 7.8 or above
risks of gestational diabetes for mother
-pre eclampsia
-premature labour
-shoulder dystocia
-failure to progress
-T2DM
risks of gestational diabetes for baby
-macrosomia
-neural tube defects
-hypoglycaemia
-respiratory distress
-jaundice
MSK adaptations
change centre of gravity
-increased lordosis
-forward flexion of neck
-stretch abdo muscles
-increased pubic symphysis mobility
-anterior tilt of pelvis
-fluid retention can compress median nerve
‘normal’ skin adaptations. why?
chloasma (tanned face)
palmar erythema
vascular spiders
linea niagra
oestrogen increases melanin
risk factors for pre eclampsia
over 40
family history
previous
HTN
BMI 30 or above
multiplie pregnancy
