Hypertension in pregnancy Flashcards
(48 cards)
What is the most common cause of iatrogenic prematurity?
Pre-eclampsia
What are the CVS system changes in pregnancy?
- Plasma volume increases by 45%
- Cardiac output increases by 30-50%
- Stroke volume increases by 25%
- Heart rate increases by 15-25%
- Peripheral vascular resistance decreases by 15-20%
What is the definition of hypertension?
>140/90mmHg on 2 occasions
>160/mmHg once
(ACOG >30/15mmHg compared to first trimester BP)
What are the three variations of hypertension in pregnancy?
- pre-existing hypertension
- pregnancy induced hypertension (PIH)
- pre-eclampsia
When is pre-existing hypertension likely
When hypertension discovered early in pregnancy
When is pre-existing hypertension a retrospective diagnosis?
If BP has not returned to nromal within 3 months of delivery
What could be the secondary causes of pre-existing hypertension?
- renal/cardiac
- cushings
- conn’s
- phaeochromocytoma
What are the risks of pre-existing hypertension?
PET (x2)
IUGR
Abruption
What is PIH?
Pregnancy induced hypertension
- happens in second half of pregnancy and resolves within 6/52 of delivery
In PIH there is no ______ or other features of ___-_____, however __% progress to pre-eclampsia
In PIH there is no proteinuria or other features of pre-eclampsia, however __% progress to pre-eclampsia
What is pre-eclampsia?
- hypertension
- proteinuria (>0.3g/l or >0.3g/24hr)
- oedema
Pregnancy multi-system disorder with unpredictable, widespread manifestations.
Describe the presentation of pre-eclampsia
May be asymptomatic at first presentation
Then diffuse vascular and endothelial dysfunction, widespread circulatory disturbance
When is pre-eclapmsia classed as early or late?
> 34 weeks
What is the pathogenesis of pre-eclampsia?
- genetic/environmental predisposition
- stage 1- abnormal placental perfusion
- placental ischaemia
- stage 2- maternal syndrome
- an anti-angiogenic state associated with endothelial dysfunction
What are genetic and environmental factors though to do that cause pre-eclampsia?
Create conditions leading to defective deep placentation; the injured placenta then releases factors into the maternal circulation that induce pre-eclapmsia
Describe the pathogenesis of abnormal placentation?
- Abnormal placentation and trophoblast invasion -> failure of normal vascular remodelling
- Spiral arteries fail to adapt to become high capacitance, low resistance vessels
- Placental ischaemia and widespread endothelial damage and dysfunction
- Mechanism unclear (??oxidative stress / PGI2: TXA2 imbalance / NO)
- Endothelial Activation causes;
- increased Capillary Permeability
- increased Expression of CAM
- increased Prothrombotic Factors
- increased Platelet aggregration
- Vasoconstriction
What maintains endothelial health in normal pregnancy?
VEGF and TGF-B1
What is excreted in excess in pre-eclampsia?
sFIt1 and sEng
- they antagonise VEGF and TGF-B1*
- sFit1 also antagonises PIGF*
What systems does pre-eclampsia affect?
- CNS
- Renal
- hepatic
- haematological
- pulmonary
- cardiovascular
- placental
Describe liver disease in pregnancy?
HELLP syndrome
Haemolysis, Elevated Liver Enzymes, Low Platelets
How might liver disease in pregnancy present?
- Epigastric/RUQ pain
- abnormal liver
- hepatic capsule rupture
Placental disease can cause;
f___ _____ r_____
_________ a________
and intrauterine _____
Placental disease can cause;
foetal growth restriction
placental abruption
and intrauterine death
What are the symptoms of pre-eclampsia?
- headache
- visual disturbance
- epigastric/RUQ pain
- nausea/volitting
- rapidly progressive oedema
What are the signs of pre-eclampsia?
- hypertension
- proteinuria
- oedema
- abdominal tenderness
- disortientation
- small for gestational age (SGA) fetus
- intrauterine fetal death
- hyper-reflexia/involuntary movements/clonus
