Physiology in pregnancy Flashcards
what general changes are seen in pregnancy
mechanical systems metabolism fatigue (particularly early) heartburn/reflux oedema breast changes thyroid changes general state of immunosuppresion weight gain
how does the appearance of the breasts change in pregnancy
increased size
increased pigmentation of the areola/nipple
secondary areola appears
montgomery tubercules appear on the areola
what happens to the vascularity of the breast
increased vascularity - breasts become warm and tender
what is expressed from the breasts and when
colostrum like fluid from the end of the third month
when do changes to the CVS start occurring
significant changes in the early first trimester
what happens to circulating blood volume
increased circulating blood volume
- 50-70% higher than non-pregnant
what happens to vascular resistance and when
systemic vascular resistance falls - maximal fall at 20-32 weeks
in relation to the CVS what occurs when a pregnancy women is in the supine position
25% reduction in cardiac output
what are some other cardiac changes
increased blood flow increased CO (40%) increased stroke volume increased heart rate increased O2 consumption
what is intrapartum
period of time from the onset of labour to the end of the third stage of labour
what are some intrapartum CVS changes
autotransfusion of contractions (blood transferred from uterus to maternal circulation
pain - increasing catecholamines
Cardiac Output increases by 10% in labour and by 80% in 1st post delivery hour
when does the CVS return to normal after pregnancy
mostly by 3 months
what happens to blood volume postpartum
decreased by 10% 3 days postpartum
what happen to BP postpartum
initially falls then increased again days 3-7 (back to pre pregnancy levels by 6 weeks)
what happens to systemic vascular resistance postpartum
increased over first 2 weeks to 30% above delivery levels
what happens to heart rate postpartum
returns to pre preg level over 2 weeks
what happens to cardiac output postpartum
increase up to 80% 1st hour post delivery then continues to fall over the next 24 weeks
what happens to O2 demand in pregnancy
increases up to 20%
what happens to minute ventilation during pregnancy
increaes 40-50%
what other respiratory factors increase during pregnancy
increased resp rate
increased tidal volume
what respiratory factors decrease during pregnancy
decreased functional residual capacity
decreased PCO2
what respiratory factors remain unchanged during pregnancy
PEFR - peak expiratory flow rate
FEV1 - forced expiratory volume in 1 minute
what happens to the urinary collecting system during pregnancy
dramatic dilatation - more pronounced on the right
what happens to renal plasma flow during pregnancy
60-80% increase by end of second trimester
what other renal system factors increase
increased GFR and creatinine clearance (50%)
increased protein excretion
increased rate with increasing gestation
what renal system factors decrease
decreased urea
decreased creatinine
what other renal changes are seen in pregnancy
oedema in 80% of women
glycosuria common
microscopic haematuria may be present
what haematological increases are seen in pregnancy
plasma volume increased (cf to birthweight)
2-3 fold increase in iron requirement
10-20 fold increase in late requirements
WCC increases
what haematological decreases are seen in pregnancy
decreased hg, script, rcc
decreased platelet count
what happens to the coagulable state during pregnancy
becomes hyper coagulable
recap - lab values that decrease
Hg Platelets (or stay the same) Urea Creatinine Urate (but increases with gestation) total protein albumin AST/A:T/GGT
recap - lab values that increase
WCC ESR 24hr protein Alkaline phosphate (***) D dimer
recap - lab values that stay the same
bile acids
AST/ALT/GGT (sometimes)
Platelets (sometimes)
