Hypertension in Pregnancy Flashcards
How common is eclampsia
1/2000 pregnancies affected
What happens to the blood vessels in pregnancy
vasodilation
What happens to the BP in early pregnancy
falls with lowest point at 22-24 wks
slowly rises until term
What happens to BP after delivery
falls but subsequently rises and peaks at 3-4 days post natal
How is hypertension diagnosed in pregnancy
more than 140/90 on 2 occasions
DBP more than 110
according to ACOG - rise of more than 30/15 compared to booking BP = hypertension
what are the three categories of hypertension in pregnancy
pre existing (first half) pregnancy induced (second half) pre eclampsia (usually ins econd half)
What are the possible risks of hypertension in pregnancy
PET
IUGR
Abruption
What are the features of PIH
Second half of pregnancy Resolves within 6 wks post partum No proteinuria Some progress to pre eclampsia High recurrence rate
What are the defining features of pre eclampsia
Hypertension
Proteinuria
Oedema
What is the pathogenesis of pre eclampsia
Genetic predisposition
Two stages: abnormal placental perfusion and maternal syndrome
What medications can be used to treat hypertension in pregnancy
- Labetalol
- Methyldopa
- Nifedipine ( if monotherapy fails)
What hypertensive medications need to be stopped in pregnancy
ACE inhibitors and ARBs ‘sartans’
How is severe hypertension treated eg 165/110
Labetalol oral or IV
Hydralazine
Nifedipine
What is the target BP in pregnancy
Aim fro less than 150/80-100
If there is organ damage er proteinuria, aim for 140/90
less than 140/90 consider reducing dose
If less than 130/90 reduce dose
When should the baby be delivered in pre eclampsia
37 weeks
Describe the pathogenesis of pre-eclampsia
Abnormal placentation and trophoblast invasion –> failure of normal vascular remodelling
Spiral arteries fail to adapt to become high capacitance, low resistance vessels
Placental ischaemia –> widespread endothelial damage and dysfunction
What CNS problems can occur due to hypertension in pregnancy
eclampsia hypertensive encephalopathy Intracranial haemorrhage Cerebral oedema cortical blindness cranial nerve palsy
What renal disease may occur due to hypertension in pregnancy
increased GFR Proteinuria increased serum uric acid (also placental ischaemia) increased creatinine / potassium / urea Oliguria /anuria Acute renal failure acute tubular necrosis renal cortical necrosis
What lifethreatening liver disease can occur due to pre-eclampsia/ high BP in pregnancy
HELLP syndrome
What dies HELLP syndrome stand for
Haemolysis
Elevated Liver enzymes
Low Platelets
What haematological conditions can occur due to high BP
decreased plasma volumeHaemo-concentration
Thrombocytopenia
Haemolysis
Disseminated Intravascular Coagulation
What CVS/lung disease can occur due to high BP in pregnancy
PE
Pulmonary oedema –> ARDS
What else is there an increased risk of in pregnancies with hypertension
IUGR due to placental insufficiency
Placental abruption
IUD
What are the symptoms of pre eclampsia
Headache Visual disturbance Epigastric /RUQ pain Nausea and vomiting Oedema which is rapidly progressing
What signs may be present in pre eclampsia
Hypertension Proteinuria Oedema Abdominal tenderness Disorientation Small for gestational age IUD Hyper-reflexia / involuntary movements / clonus
What are the risk factors for preeclampsia
Maternal Age (>40 years 2X) Maternal BMI (>30 2X) Family History (20-25% if mother affected, up to 40% if sister) Parity (first pregnancy 2-3X) Multiple pregnancy (Twins 2X) Previous PET (7X) Molar Pregnancy / Triploidy
Multiparous women develop more severe disease
What medical conditions make a woman more at risk of pre eclampsia
Pre-existing renal disease Pre-existing hypertension Diabetes Mellitus Connective Tissue Disease Thrombophilias (congenital / acquired
What test can be done to predict pre eclampsia and at what gestation
Maternal uterine artery Doppler
20-24 weeks
When would you admit a woman with pre eclampsia
BP >170/110 OR >140/90 with (++) proteinuria
Significant symptoms - headache / visual disturbance / abdominal pain
Abnormal biochemistry
Significant proteinuria - UPCR >30mg/mmol
Need for antihypertensive therapy
Signs of fetal compromise
How are in patients with pre eclampsia assessed
Blood Pressure - 4 hourly
Urinalysis - daily
Input / output fluid balance chart
UPCR - if proteinuria on urinalysis
Bloods - FBC, U&Es, Urate, LFTs. Minimum X2 per week
How is the fetus monitored in fetal surveillance
Fetal Movements
CTG - daily
Ultrasound
Biometry
Amniotic Fluid Index
Umbilical Artery Doppler
At what MAP is there a significant risk of cerebral haemorrhage
more than 150mmHg
When should you treat hypertension in pregnancy
if BP more than 150/100
How is MAP calculated
(2x diastolic + systolic) /3
What is the mechanism of action of methyldopa
centrally acting alpha agonists
Mechanism of action of labetalol
alpha and beta agonist
Mechanism of action of nifedipine
calcium channel antagonist
Mechanism of action of hydralzine
vasodilator
Contraindications of methyldopa
depression
contraindications of labetalol
asthma
What is the cure for pre eclampsia
deliver baby
What would be indications for delivery
Term gestation Inability to control BP Rapidly deteriorating biochemistry / haematology Eclampsia Other Crisis Fetal Compromise - REDF, abnormal CTG
List crises in pre eclampsia
Eclampsia HELLP syndrome Pulmonary Oedema Placental Abruption Cerebral Haemorrhage Cortical Blindness DIC Acute Renal Failure Hepatic Rupture
What is eclampsia
Grand mall seizure with symptoms/features of pre eclampsia
when does most eclampsia occur
post partum
what age group is eclampsia more common in
teenagers
What are the four principles of managing severe PET/eclampsia
control bp
stop/prevent seizures
fluid balance
delivery
What is given for seizure treatment /prophylaxiz
magnesium sulphate 4g IV over five mins
maintain with IV infustion 1g/h
if further seizures admister 2g Mg sulphate
If persistant consider diazepam,
what is the main cause of death in pre eclampsia
pulmonary oedema
What should be given with caution in pts with preeclampsia or eclampsua
IV fluids - safer to run patient dry
When is low dose aspirin given
high risk women (previous PET etc)
best at preventing severe early onset pre eclampsia
commence before 12 weeks