HYPERTENSION IN PREGNANCY Flashcards
What are the three categories of hypertension in a pregnant woman?
Pre-existing or chronic hypertension
Gestational or pregnancy induced hypertension
Pre-eclampsia or proteinuric hypertension
What is the definition of pregnancy induced hypertension?
Hypertension presenting after 20 weeks of pregnancy with no previous history of hypertension and in the absence of proteinuria.
What is the definition of pre-eclampsia?
New hypertension developing after 20 weeks of pregnancy with significant proteinuria.
What is considered mild hypertension in the context of pregnancy?
Less than 149/99 mmHg
What is considered moderate hypertension in the context of pregnancy?
Between 150/100 mmHg and 159/109 mmHg
What is considered severe hypertension in the context of pregnancy?
Over 160/110 mmHg
What are the risk factors for developing pre-eclampsia?
High risk:
Previous history of pre-eclampsia
Chronic kidney disease
Diabetes (I + II)
SLE
Antiphospholipid syndrome
Moderate risk:
Primips
Age over 40
BMI over 35kg
Family Hx of pre-eclampsia (especially sister)
Multiple pregnancy
Hypertension in pregnancy is for the most part asymptomatic, however, what symptoms must you ask about when taking a history from a hypertensive pregnant woman that might indicate pre-eclampsia?
Headache
Visual disturbances - typically flashing lights (sign of papilloedema)
Right upper quadrant pain - oedema in liver capsule
Vomiting
Swelling of hands, feet or face.
Why is it important to ask about a previous use of the contraceptive pill when taking the history from a hypertensive pregnant woman?
A history of hypertension when taking the oral contraceptive pill indicates a susceptibility to high blood pressure in pregnancy.
On examination of a patient with pregnancy induced hypertension or pre-eclampsia, what might you expect to find?
Raised BP
Facial oedema
Papilloedema
Brisk reflexes
Clonus
Liver tenderness
Small uterus for dates
What investigations would you do in a pregnant patient with hypertension?
Urine dipstick
MSU urinalysis - protein creatinine ratio
24 hour urine collection
FBC
U&Es
LFTs
Clotting
USS - fetal growth can be affected
What would the urine dipstick of a patient with pre-eclampsia reveal?
More than 2+ protein
What would urinalysis of a patient with pre-eclampsia reveal?
A protein creatinine ratio of more than 30
What amount of protein in the urine over 24 hours would be considered significant for pre-eclampsia?
0.3g
How would the FBC of a woman with pregnancy induced hypertension be different from the FBC of a woman with pre-eclampsia?
PIH:
Normal
PET:
Low platelet
High haematocrit
How would the U&Es of a woman with pregnancy induced hypertension be different from the U&Es of a woman with pre-eclampsia?
PIH:
Normal (or at least no change from booking screen)
PET:
High creatinine
How would the LFTs of a woman with pregnancy induced hypertension be different from the LFTs of a woman with pre-eclampsia?
PIH:
Normal
PET:
High ALT and AST
How would the clotting screen of a woman with pregnancy induced hypertension be different from the clotting screen of a woman with pre-eclampsia?
PIH:
Normal
PET:
Deranged
What is HELLP syndrome?
Haemolysis Elevated Liver enzymes and Low Platelets
It is a severe form of pre-eclampsia which is named after its features.
How do we manage pregnant patients with pre-existing essential hypertension?
Aim to keep BP below 150/100 mmHg, unless they have end organ damage (renal or retinal) in which case aim to keep below 140/90 mmHg, using antihypertensives.
If using ACE inhibitors or angiotensin receptor antagonists, these must be stopped and replaced with another. First line is labetalol.
Low dose aspirin (75mg) daily from 12 weeks gestation until delivery has been shown to reduce risk of developing pre-eclampsia.
How do we manage pregnant patients with pregnancy induced hypertension?
Aim to keep BP below 150/100 mmHg, unless they have end organ damage (renal or retinal) in which case aim to keep below 140/90 mmHg, using antihypertensives. First line is labetalol.
Low dose aspirin (75mg) daily from 12 weeks gestation until delivery has been shown to reduce risk of developing pre-eclampsia.
Early delivery before 37 weeks is not usually indicated but if there are signs of fetal compromise should be considered and where possible in this scenario a course of steroids should be administered to aid fetal lung maturity.
How do we manage patients with pre-eclampsia?
Aim to keep BP below 150/100 mmHg. Those with severe (above 160/110 mmHg) if not responsive to first-line therapy may require urgent IV anti-hypertensives (eg hydralazine).
Low dose aspirin (75mg) daily from 12 weeks gestation until delivery
Where the mean arterial pressure remains above 125 mmHg and the patient is experiencing symptoms, there is a risk of eclampsia and prophylactic IV magnesium sulphate should be considered.
Limit fluid intake
What are the anti-hypertensives that should definitely not be used in pregnancy?
ACE inhibitors
Angiotensin II receptor antagonists
What is the first line medication for treating hypertension in pregnancy? Include dose.
Labetalol - 100 mg BD
What class of drug is labetalol?
Alpha and beta blocker
In which pregnant patients would labetalol be contraindicated to treat hypertension?
Asthmatics
If labetalol is contraindicated or hypertension in pregnancy is not responding to the medication, what are the other antihypertensives that can be used in pregnancy? Include dose.
Methyldopa - 250 mg BD/TDS
Nifedipine (modified-release preparation) - dose dependent on brand
What are the side effects of nifedipine?
Headaches
Weight gain
If prescribing methyldopa for a pregnant woman with hypertension, what must you tell her regarding her prescription?
She must stop methyldopa within 2 days of delivery and be swapped to another agent as methyldopa increases risk of post-natal depression.
What class of drug is nifedipine?
Calcium channel blocker
What class of drug is methyldopa?
Alpha agonist which prevents vasoconstriction
What is eclampsia?
Seizures that occur in pregnancy on a background of pre-eclampsia.
What is the incidence of eclampsia?
1 in 2000
What percentage of patients who suffer eclampsia have there seizures postnatally?
40% (normally occur within 48 hours of delivery)
What is the differential diagnosis of seizures within pregnancy?
Epilepsy
Meningitis
Cerebral thrombosis
Intracerebral bleed
Intracerebral tumour
Seizures presenting for the first time in pregnancy should always be assumed to be eclamptic until proven otherwise.
How do you manage a patient with eclampsia?
ABCDE approach
MgSO4 - 4 gram IV bolus over 5 minutes, a further dose of 2–4 g given over 5 minutes if the woman is having recurrent seizures
MgSO4 - 1 gram/hour for 24 hours after last seizure
Treat hypertension using IV antihypertensives
Consider delivery based on response
If using hydralazine IV as an antihypertensive in a pregnant woman, what must you give the patient before administering the drug?
Bolus of fluid as can cause rapid hypotension.
Do we give prophylactic treatment for pre-eclampsia?
Yes. Women with 2 or more moderate risk factors or any high risk factors should be given prophylactic aspirin 75 mg.
Moderate risk factors:
First pregnancy
BMI > 35 kg/m2
Age over 40
Family history of first degree relative with pre-eclampsia (Mother or sister)
Multiple pregnancy (e.g. twins)
Pregnancy interval of more than 10 years
Severe risk factors:
Hypertensive disease during previous pregnancy
Chronic kidney disease
Autoimmune disease such as systemic lupus
erythematosis or antiphospholipid syndrome
Type 1 or type 2 diabetes
