Hypertension in Pregnancy Flashcards
(41 cards)
only cure of pre-eclampsia?
delivery of baby
- irrespective of gestational age of baby
what cardiovascular changes occur in pregnancy?
plasma volume increases
CO increases
stroke volume increases
HR increases
slight BP drop in mid-trimester which then rises again slightly
peripheral vascular resistance decreases (to accommodate other changes)
definition of hypertension in pregnancy?
> 140/90 on 2 occasions
or
160/110 once
3 classifications of hypertension in pregnancy?
pre-existing hypertension
pregnancy induced hypertension (PIH)
pre-eclampsia
how is pre-existing hypertension diagnosed?
usually diagnosed before pregnancy
likely to be pre-existing if present in early pregnancy
may be a retrospective diagnosis if BP hasnt resolved within 3 months after delivery
risks of pre-existing hypertension in pregnancy?
PET
IUGR
abruption
when does PIH generally occur?
2nd half of pregnancy
usually resolves within 6 weeks of delivery
high recurrence rate
how is PIH different to pre-eclampsia?
no proteinuria or other features of pre-eclampsia (oedema etc)
better outcomes than pre-eclampsia
although 15% can progress to pre-eclampsia
features of pre-eclampsia?
hypertension
protienuria (>0.3g/l or >0.3g/24hrs)
oedema
diffuse vascular endothelial dysfunction and widespread circulatory disturbance in whichever system affected (cardio, renal etc)
absence does not exclude diagnosis however
may be asymptomatic at time of first presentation
2 sub-types of pre-eclampsia?
early (<34 weeks)
- common
- associated with villous and vascular lesions of placenta
- higher risk of maternal and foetal complications than late
late (>34 weeks)
- more common
- minimal placental lesions
- maternal factors (such as metabolic syndrome etc) can have important roles
- most cases of eclampsia and maternal death in late
phases in pathogenesis of pre-eclampsia?
genetic/environmental predisposition
stage 1
- failure of placental development causing abnormal placental perfusion and ischaemia
stage 2 (matenal syndrome)
- an anti-androgenic state associated with endothelial dysfunction
what changes occur in the placenta in pre-eclampsia?
abnormal placentation and trophoblast invasion leads to failure of normal vascular remodelling
spiral arteries then fail to adapt to become high capacitance, low resistance narrow vessels
placental ischaemia occurs which leads to widepsread endothelial damage and dysfunction
endothelial damage leads to
- increased capillary permeability, CAM expression, prothrombic factors and platelet aggregation and vasoconstriction
what systems can be affected by pre-eclampsia?
CNS renal hepatic haematological pulmonary cardiovascular placental
liver disease in pre-eclampsia?
HELLP syndrome
- haemolysis
- elevated
- liver enzymes
- low
- platelets
features of HELLP syndrome?
epigastric/RUQ pain
abnormal liver enzymes
hepatic capsule rupture
how can pre-eclampsia affect placenta?
fetal growth restriction placental abruption (can cause post partum haemorrhage) intra-uterine death
common symptoms of pre-eclampsia?
headache visual disturbance epigastric/RUQ pain nausea/vomiting rapidly progressive oedema (may vary in timing, progression and order of symptoms)
signs of pre-eclampsia?
hypertension proteinuria oedema abdominal tenderness disorientation small for gestational age intra-uterine fetal death hyper-reflexia/involuntary movements/clonus
how is pre-eclampsia investigated?
urea and electrolytes serum urate (one of the 1st things to increase) LFTs (haemolysis, thrombocytopaenia) FBC coagulation screen urinalysis (protein/creatinine ratio) cardiotocography US (fetal assessment)
how is pre-eclampsia managed?
assess risk if hypertension present <20 weeks - look for 2ndary cause antenatal screening (BP, urine, MUAD) treat hypertension maternal and fetal surveillance timing of delivery
risk factors for pre-eclampsia?
maternal age (>40) maternal BMI (>30) family history parity (higher risk if first) multiple pregnancy previous pre-eclampsia birth interval > 10 years molar pregnancy/triploidy disease is more severe in multiparous women
medical risk factors for pre-eclamspia?
pre-existing renal disease pre-existing hypertension diabetes (pre-existing/gestational) connective tissue disease thrombophilias (congenital/acquired)
what can be used to prevent pre-eclamspia?
low dose aspirin
used in high risk women (renal, diabetes, APS, multiple risk factors, previous pre-eclampsia etc)
150mg commenced before 16 weeks
how does aspirin work?
inhibits COX enzyme which prevents TXA2 synthesis
