HTN in pregnancy Flashcards
why does BP fall in early pregnancy
vasodilatation
definition of HTN in pregnancy
> 140/90 mmHg on 2 occasions
>160/110 mmHg on 1 occasion
types of HTN in pregnancy
pre-existing HTN
pregnancy induced HTN (PIH)
pre-eclampsia
HTN in the first trimester is most likely to be
pre-existing HTN
what are secondary causes of HTN in pregnancy
renal/cardiac causes
Cushing’s
Conn’s
phaeochromocytoma
how is PIH istinguised from pre-eclampsia
no proteinuria or other features of pre-eclampsia
what is the likelihood of progressing from PIH to pre-eclampsia
15%
signs of pre-eclampsia
hypertension
proteinuria
oedema
(absence of one doesn’t exclude the diagnosis)
what is pre-eclampsia
diffuse vascular endothelial dysfunction widespread circulatory disturbance
which systems are affected by pre-eclampsia
renal hepatic CV haematology CNS placenta
late vs early pre-eclampsia
early onset = <34 weeks
late onset = >34 weeks
more common; late or early onset pre-eclampsia
late-onset
which type of pre-eclampsia has higher risks for mother and baby
early onset
pathogenesis of pre-eclampsia
genetic/environmental predisposition
stage 1 - abnormal placental perfusion
stage 2 - maternal syndrome (anti-angiogenic state associated with endothelial dysfunction)
what is the outcome of trophoblast invasion in normal placentation and how does this differ in pre-eclampsia
trophoblasts invade the muscular layer around the spiral artery to reduce vascular resistance and increase blood flow
in pre-aclmapsia there is no trophoblast invasion which results in high-pressure and low blood flow
CNS disease in pre-eclampsia
eclampsia hyertensive encephalopathy intracranial haemorrhage cerebral oedema cortical blindness cranial nerve palsy
renal disease in pre-eclampsia
decreased GFR proteinuria high serum uric acid high creatinine/potassium/urea oliguria/anuria acute renal failure
liver disease in pre-eclampsia
epigastric/RUQ pain
abnormal liver enzymes
hepatic capsule rupture
HELLP syndrome
what are characteristics of HELLP syndrome
Haemolysis
Elevated Liver enzyme
Low Platelets
haematological disease in pre-eclampsia
decreased plasma volume haemorrhage-concentration thrombocytopenia haemolysis DIC
cardiorespiratory disease in pre-eclampsia
pulmonary oedema –> ARDS
pulmonary embolus
high mortality
placental disease in pre-eclampsia
fatal growth restriction
placental abruption
intrauterine death
symptoms of pre-eclampsia
headache visual disturbance epigastric/RUQ pain nausea/vomiting rapidly progressive oedema
signs of pre=eclampsia
HTN proteinuria oedema abdominal tenderness disorientation small for gestational age intrauterine death hyper-reflexia/involuntary movements/clonus (>2 beats)
investigations for pre=eclampsia
U&Es serum urate LFTs FBC coag screen urine PCR CTG USS (fetal biometry, AFI, doppler)
management of pre-eclampsia
assess risk at booking HTN <20 weeks (look for secondary cause) antenatal screening (BP, urine, MUAD) treat HTN maternal and fatal surveillance timing of delivery
what is MUAD
maternal uterine artery doppler studies
what is MUAD used for
to determine is placentation has been successful
risk factors for pre-eclampsia
>40 BMI >30 FHx parity (first pregnancy) multiple pregnancy previous PE birth interval >10 years molar pregnancy/triploidy
how does parity affect the severity of pre-eclampsia
more likely to happen if primiparous
more severe disease in multiparous women
medical risk factors for pre-eclampsia
pre-existing renal disease pre-existing HTN diabetes connective tissue disease thrombophilias
who is low dose aspirin used in
high risk women (renal, DM, aPS, multiple risk factors, previous PET
when should low dose aspirin be started
before 12 weeks
what dose of aspirin is used in pre-eclampsia prophylaxis
75 mg
when to refer to antenatal daycare unit
BP >140/90
proteinuria (++)
oedema
symptoms (especially persistent headache)
when to admit
BP >170/110 or >140/90 with ++ proteinuria significant symptoms abnormal biochemistry significant proteinuria >300 mg/24 hours need for antihypertensive therapy signs of fatal compromise
inpatient assessment
blood pressure 4 hourly urinalysis daily input/output fluid balance urine PCR bloods
treatment of HTN
aim for 140-150/90-100 mmHg
first line labetolol
second line nifedipine
3rd line methyl dopa
what is labetolol
alpha nad beta agonist
NO ASTHMA
what is nifedipine
Ca channel agonist
what is methyl dopa
centrally acting alpha blocker
why might pregnancy antihypertensive therapy might be poorly tolerated
labetolol - asthma
methyl-dopa - depression
nifedipine - headache
indications for birth
term gestation inability to control BP rapidly deteriorating biochemistry/haematology eclampsia other crisis fetal compromise
crises in pre-eclampsia
eclampsia HELLP syndrome pulmonary oedema placental abruption cerebral haemorrhage cortical blindness DIC acute renal failure hepatic rupture
what is eclampsia
tonic-clonic (grand mal) seizure occurring with features of pre-eclampsia
management of severe PET/eclampsia
control BP
stop/prevent seizures
fluid balance
delivery
management of seizures in pregnancy
magnesium sulphate
post-partum management of eclampsia
breast-feeding contraception BP management counselling future risk long term CVD risk
