Hypertensive Disorders in Pregnancy

Question 1

When does blood pressure fall to a minimum level during pregnancy?

when does it go back to ‘normal’

Answer 1

2nd trimester - by about 30/15mmHg because of reduced vascular resistance

By term, blood pressure rises again to pre-pregnant levels

Question 2

What is the cause of hypertension due to pre-eclampsia?

Answer 2

increase in systemic vascular resistance

Question 3

Excretion of what substance is increased in normal pregnancy?

Answer 3

protein (still less than 0.3g/24 hours in the absence of renal disease)

Question 4

What is pregnancy induced hypertension?

Answer 4

When the blood pressure rises above 140/90mmHg after 20 weeks

Question 5

What are the causes of pregnancy induced hypertension?

Answer 5

Pre-eclampsia or transint hypertension

Question 6

What is pre-eclampsia?

Answer 6

Pre-eclampsia refers to new high blood pressure (hypertension) in pregnancy with end-organ dysfunction, notably with proteinuria (protein in the urine). It occurs after 20 weeks gestation

Question 7

What is the difference between pre-eclampsia and gestational hypertension?

Answer 7

Gestational hypertension - new hypertension presenting after 20 weeks without proteinuria

HOWEVER, occasionally, proteinuria is absent in pre-eclampsia, particularly in early pregnancy

Question 8

What is pre-existing hypertension

Answer 8

When blood pressure is >140/90mmHg before pregnancy or before 20 weeks gestation, or the woman is already on hypertentive treatment

May be primary hypertension or secondary to renal or other disease - may also be pre-existing proteinuria because of renal disease

Question 9

What is pre-eclampsia?

Answer 9

Multisystem syndrome that usually manifests as new hypertension after 20 weeks with significant proteinuria

specific to pregnancy, of placental origin and cured only be delivery

Question 10

What are the effects of pre-eclampsia?

Answer 10

Blood vessel endothelial cell damage leads to vasospasm, increased capillary permeability and clotting dysfunction - both the foetus and mother are a risk

Question 11

What are the two phenotypes of pre-eclampsia?

Answer 11

Early onset - that which causes complications before 34 weeks: typically the foetus is growth restricted

Late onset - manifest at any later gestation - not usually associated with growth restriction, although fetal death and damage may occur

Question 12

What is the first step in the pathophysiology of pre-eclampsia?

Answer 12

Poor placenta perfusion

Question 13

What happens in normal pregnancy to allow adequate placenta perfusion?

Answer 13

Trophoblastic invasion of spiral arterioles leads to vasodilation of vessel walls to allow adequate placenta perfusion

Question 14

How is pre-eclampsia caused?

Answer 14

Pre-eclampsia is caused by high vascular resistance in the spiral arteries and poor perfusion of the placenta. This causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation, leading to systemic inflammation and impaired endothelial function in the blood vessels.

Question 15

What is pre-eclampsia as opposed to severe pre-eclampsia?

Answer 15

Pre-eclampsia - new hypertension presenting after 20 weeks with significant proteinuria

severe pre-eclampsia - pre-eclampsia with severe hypertension and/or with symptoms and/or biochemical and/or haematological impairment

Question 16

What are the classifications of hypertension?

Answer 16

Mild - 140/90 - 149/99mmHg
Moderate - 150/100 - 159/109mmHg
Severe >160/110mmHg

Question 17

What are the classifications of pre-eclampsia?

Answer 17

mild/moderate: pre-eclampsia without severe HTN and no symptoms and no biochemical or haematological impairment

Severe- pre-eclampsia with severe HTN and/or with symptoms, biochemical or haematological impairment

Early: <34 weeks
Late >34 weeks

Question 18

Describe the epidemiology of pre-eclampsia?

Answer 18

Affects 6% of nulliparous women

less common in multiparous women unless additional risk factors are present

15% recurrence risk
this is up to 50% if there has been severe pre-eclampsia before 28 weeks

Question 19

What are the predisposing factors for pre-eclampsia?

Answer 19

High-risk factors are:
Pre-existing hypertension
Previous hypertension in pregnancy
Existing autoimmune conditions (e.g. systemic lupus erythematosus)
Diabetes
Chronic kidney disease

Moderate-risk factors are:
Older than 40
BMI > 35
More than 10 years since previous pregnancy
Multiple pregnancy
First pregnancy
Family history of pre-eclampsia

Women are offered aspirin from 12 weeks gestation until birth if they have one high-risk factor or more than one moderate-risk factors.

Question 20

What are the clinical features of pre-eclampsia?

Answer 20

Headache
Visual disturbance or blurriness
Nausea and vomiting
Upper abdominal or epigastric pain (this is due to liver swelling)
Oedema
Reduced urine output
Brisk reflexes

Hypertension = usually the first sign - massive oedema is also found in pre-eclampsia, not postural or of sudden onset

presence of epigastric tenderness is suggestive of impending complications

urine dipstick testing for protein should be considered part of clinical exam

Question 21

What do the following indicate:

trace

Dipstick 1+ for protein

Dipstick >2+ for protein

PCR >30mg/nmol

24h collection >0.3g/24h

Answer 21

trace - seldom significant

1+ - possible significant proteinuria: quantify

> 2+ - significant proteinuria likely: quantify

PCR >30mg/nmol: confirmed significant proteinuria

24h collection: confirmed significant proteinuria

Question 22

What are the maternal complications of pre-eclampsia?

Answer 22

ECLAMPSIA

CV haemorrhage

Fluid overload

Renal failure

Liver failure - rupture/ HELPP

PE - give enoxaparin

DIC - prevent

placental abruption

Question 23

What is eclampsia?

Answer 23

grand mal seizure resulting from cerebrovascular vasospasm - mortality can result from hypoxia and concomitant complications of severe disease

Treatment: magnesium sulphate and intensive surveillance for other complications

Question 24

What Is the cause of cerebrovascular haemorrhage?

Answer 24

failure of cerebral blood flow auto regulation at MABP >140mmHG

Question 25

What liver and coagulation problems result from pre-ecalmpsia?

Answer 25

HELLP syndrome Haemolysis Elevated Liver enzymes Low Platelets DIC, liver failure and liver rupture may also occur treatment Is supportive and includes magnesium sulphate prophylaxis against eclampsia - liver infarction or subscapsular haemorrhage may occur

Question 26

How is renal failure identified?

Answer 26

careful fluid balance monitoring and creatine measurement Haemodialysis is required in severe cases

Question 27

What is pulmonary oedema as a result of pre-eclampsia treated with?

Answer 27

oxygen and furosemide and assisted ventilation may be required - ARDS may develop

Question 28

What are the fetal effects of pre-eclampsia?

Answer 28

perinatal mortality and morbidity of the foetus = increased 5% stillbirths 10% preterm deliveries accounted for by pre-eclampsia growth restriction (early onset) at term - affects foetal growth less, but is still associated with increased morbidity and mortality at all gestations, there is an increased risk of placental abruption

Question 29

What investigations should be done for pre-eclampsia?

Answer 29

if bed stick urinalysis is +ve, the protein is quantified - 24hr urine or PCR is used 30mg/nmol or 0.3g/24hr protein excretion - proteinuria may be absent in early disease and testing for proteinuria is repeated Blood tests - elevation of uric acid. HB often high and rapid fall in platelets due to aggregation on damaged endothelium - impending HELLP Rise IN LFTs (ALT) - impending liver damage LDH levels rise Renal function mildly impaired - rising creatinine USS

Question 30

What is the most common screening test for early prediction?

Answer 30

uterine artery Doppler at 20 weeks - sensitivity for PE at any stage in pregnancy is about 40% for a 5% screen-positive rate

Question 31

What is the screening test for late prediction of PE?

Answer 31

placental growth factor (PlGF) testing on one occasion during pregnancy in women suspected of having pre-eclampsia. Placental growth factor is a protein released by the placenta that functions to stimulate the development of new blood vessels. In pre-eclampsia, the levels of PlGF are low.

Question 32

What is the prevention of pre-eclampsia?

Answer 32

low-dose aspirin (75mg) before 16 weeks (evening) reduces the risk of pre-eclampsia and is now NICE recommended. High dose vitamin D with Ca2+ supplementation might also be effective

Question 33

What is the management of pre-eclampsia?

Answer 33

Assessment - day assessment sFlt-1:PIGF ratio pts without proteinuria and with mild/moderate hypertension are usually managed as outpatients - BP and urinalysis repeated 2/week - USS 2-4 weeks unless suggestive of foetal compromise Admission Drugs

Question 34

What are the indications for admission with pre-eclampsia?

Answer 34

Necessary with severe HTN and presence of proteinuria - if hypertension absent but proteinuria, they should be admitted Assessment using sFlt-1:PIGF assay may determine which women are most at risk and should be admitted

Question 35

What drugs are used in pre-eclampsia?

Answer 35

Labetolol is first-line as an antihypertensive Nifedipine (modified-release) is commonly used second-line Methyldopa is used third-line (needs to be stopped within two days of birth) Intravenous hydralazine may be used as an antihypertensive in critical care in severe pre-eclampsia or eclampsia IV magnesium sulphate is given during labour and in the 24 hours afterwards to prevent seizures Fluid restriction is used during labour in severe pre-eclampsia or eclampsia, to avoid fluid overload Steroids if delivery before 36 weeks

Question 36

What are the indications of antihypertensives? | Which drugs are used?

Answer 36

Given if BP reaches 150/100mmHg - labetalol maintenance is recommended Oral nifedipine for initial control with IV labetalol as 2nd line with severe hypertension aim for BP is 140/90

Question 37

What Is magnesium sulphate used for in pre-eclampsia?

Answer 37

used in both treatment and prevention - IV loading dose followed by IV infusion increased cerebral perfusion so treats underlying pathology of eclampsia toxicity is severe, resulting respiratory depression, hypotension, loss of patellar reflex

Question 38

What are steroids used for in pre-eclampsia?

Answer 38

promote foetal pulmonary maturity if the gestation is <34 weeks

Question 39

At what gestation should women with pre-eclampsia be delivered?

Answer 39

36 weeks

Question 40

At what gestation should women with gestational hypertension be delivered?

Answer 40

40 weeks as usual , as long as foetal compromise is monitored

Question 41

What are the indications for C-section in PE?

Answer 41

Before 34 weeks If severe growth restriction abnormal CTG

Question 42

What things need to be given in labour for PE?

Answer 42

Induction - prostaglandin anti-hypertensives maternal pushing avoided in 2nd stage if BP is 160/110 oxytocin instead of ergometrine - 3rd stage as latter can increase BP

Question 43

What is the postnatal care for PE?

Answer 43

Enalapril (first-line) Nifedipine or amlodipine (first-line in black African or Caribbean patients) Labetolol or atenolol (third-line)

Question 44

What is pre-existing hypertension in pregnancy?

Answer 44

When BP is already treated or exceeds 140/90 before 20 weeks

Question 45

Who is pre-existing hypertension more common in?

Answer 45

Older women Obese women Positive FH Developed HTN on COCp

Question 46

What is secondary HTN commonly associated with?

Answer 46

``` Obesity Diabetes Renal disease - ADPKD, renal artery stenosis or chronic pyelonephritis PCC Cushing's syndrome Cardiac disease Coarctation of the aorta ```

Question 47

What investigations are done for pre-existing HTN?

Answer 47

Renal function assessed and renal USS performed PCC excluded quantification of any proteinuria and uric acid level allow comparison in later pregnancy

Question 48

Why are ACE-i not used in preganancy?

Answer 48

Teratogenic and affect foetal urine production

Question 49

What drugs are normally used to treat maternal HTN in pregnancy?

Answer 49

Labetalol Nifedipine

Question 50

Why might treatment not be needed in 2nd trimester?

Answer 50

Physiological fall in BP

Question 51

What other measures are put in place for pre-existing maternal HTN?

Answer 51

low dose aspirin advised - 75mg screening using uterine artery doppler and additional antenatal visits are usual Delivery: 38-40 weeks