Hypertension in pregnancy (04/11/2021)

Question 1

What is the incidence of hypertension in pregnancy and who is it more likely to effect?

Answer 1

10%. Pre-eclampsia 5% more likely in sub saharan African women

Question 2

Why did the rates fall from 1950-70

Answer 2

Wider provision and access to AN care. Improved nutrition post war national milk and vitamin schemes so calcium intake

Question 3

Improvement since 80-90s?

Answer 3

Improvements in the organisation of care/clinical management

Question 4

Why did rates steeply fall in 2010?

Answer 4

Publication of NICE guidance

Question 5

Hypertension

Answer 5

A blood pressure of 140 systolic or higher, and diastolic of 90 or higher

Question 6

Chronic hypertension

Answer 6

Hypertension that is present at booking or before 20 weeks or if it is already present before pregnancy. Can be primary or secondary.

Question 7

Gestational hypertension

Answer 7

New hypertension presenting after 20 weeks of pregnancy without significant proteinuria

Question 8

Severe hypertension

Answer 8

Blood pressure over 160 systolic or 110 diastolic

Question 9

Eclampsia

Answer 9

A convulsive condition with pre-eclampsia

Question 10

Pre-eclampsia

Answer 10

New onset of hypertension after 20 weeks of pregnancy and the coexistence of 1 or more of proteinuria, renal insufficiency, liverinvolvement, neurological complications, haematological complications and uteroplacental dysfunction.

Question 11

Proteinuria

Answer 11

-Urine protein creatinine ratio of 30mm or more or albumin creatinine ratio of 8mg or more.

Question 12

Renal Insufficiency

Answer 12

Creatinine level 90micromol/litre or more.

Question 13

Liver involvement

Answer 13

Elevated transaminases (alanine aminotransferase or aspartate aminotransferase over 40IU/Litre) with or without right upper quadrant or epigastric abdominal pain.

Question 14

Neurological complications

Answer 14

Eclampsia, altered mental status, blindness, stroke, clonus, severe headaches, or persistent visual scotomata.

Question 15

Haemotological complications

Answer 15

Thrombocytopenia (Platelet count below 150,000/microletre) disseminated intravascular coagulation or haemolysis.

Question 16

Uteroplacental Dysfunction

Answer 16

Such as fetal growth restriction, abnormal umbilical artery doppler waveform analysis, or still birth.

Question 17

Describe the pathophysiology of hypertension

Answer 17

• Trophoblast go into decide and myometrium and strip away muscle from spiral arteries into low resistance vessels from high resistance vessels.
• The trophoblast cells don’t remodel the spiral arteries in the same way in a woman with hypertension. The spiral arteries remain more narrow, and highly resistant. Reduced blood flow to the placenta.

Question 18

What factors pre-implantation can influence hypertension?

Answer 18

• Inflammation/metabolic disorder
• Genetics
• Abnormal Angiotensin 2 response
• Fetal genetics

Question 19

What is stage one of hypertension in pregnancy and at what gestation?

Answer 19

Deflective trophoblast invasion following implantation before 12 weeks

Question 20

What occurs due to deflective trophoblast invasion, what phase?

Answer 20

Stage 2, 28 weeks, a stressed placenta due to reduced uteroplacental blood flow releasing factors triggering endothelial dysfunction.

Question 21

What is stage 3, what is it caused by?

Answer 21

Manifestation of maternal syndrome, signs and symptoms of pre-eclampsia post 28 weeks. leaky glomeruli in the kidneys so protein in the urine. Coagulation at the blood-brain barrier causing seizures.

Question 22

What are the systemic effects of pre-eclampsia?

Answer 22

High level of pro-inflammatory cytokines

• increased capillary permeability
• Endothelial dysfunction
• Release of vasoconstrictors
• Decrease in prostacyclin synthesis
• Leading to platelet activation, vasoconstriction and microvascular damage.
• hypertension and organ damage

Question 23

What are the two placental factors on a blood test associated with PE?

Answer 23

Increased Sflt-1 and Endoglin compared to normal pregnancy.

Question 24

Describe the angiogenic factors in PE?

Answer 24

Sflt-1 binds proangiogenic factors VEGF and PIGF. Endoglin antiangiogenic glycoprotein endometrium and syncytiotrophoblast.

Question 25

Are GH and PE the same disorder in terms of pathophysiology?

Answer 25

NO

Question 26

Describe the differences between GH and PE?

Answer 26

Studies suggest distinct differences in the pathophysiology between gestation hypertension and pre-eclampsia. GH is less evident for systemic cardiovascular maladaptation and abnormality in anti-angiogenic markers.

Question 27

How can we reduce risk antenatally?

Answer 27

-At booking assess risk factors, refer for early obstetric opinion. Anti-platelet agents (aspirin 75-150mg from 12 weeks to birth).

Question 28

How can we reduce risk pre-conception?

Answer 28

• Reduce BMI if overweight or obese

- Stop smoking

Question 29

Describe the assessment of someone with new hypertension?

Answer 29

• Assess risk factors and gestational age
• Do blood pressure. Is the systemic BP more than 140 and diastolic BP more than 90 twice 4 hours apart. Or is there one single reading of a BP 160 or more over 110 or more.
• Avoid morning sample, but is there proteinuria in the urine.
• Assess symptoms
• Sflt-1/PIGF testing recommended to help ‘rule in’ PE for women with gestational hypertension between 20-35 weeks.
• Fetal assessments associated with placental insufficiency, FGR, still birth. Assess growth, chat, activity, USS fetal growth, amniotic fluid volume, umbilical artery doppler.

Question 30

What is the treatment of hypertension?

Answer 30

• first line is labetalol, a beta blocker contraindicated by pregnancy.
• Next line is nifedipine if labetalol not suitable
• Methyldopa if others not suitable
• Amlodipine can replace nifedipine and doxazosin is useful when stuck
• IV drugs may be needed if severe hypertension and critical care need labetalol or hydralazine

Question 31

When does hypertension become severe?

Answer 31

it becomes severe pre-eclampsia when unresponsive to treatment or associated with symptoms.

Question 32

Consider magsulf to prevent eclamptic seizures and fetal neuroprotection >30 weeks. Loading dose 4g over 5-15 minutes, 1g/ hour 24 hours.

Answer 32

-Antenatal corticosteroids (24 to 35+6 weeks).