Pre-ecampsia

Question 1

What is pre-eclampsia? and what are the common manifestations?

Answer 1

Diffuse vascular endothelial dysfunction, with circulatory disturbances - renal, hepatic, CV, CNS and coagulation systems

Manifests as Hypertension, proteinuria and oedema - occurs after 34 weeks, more common in primagravida

Question 2

What is the pathogenesis of pre-eclampsia?

Answer 2

Genetic predisposition

Problem of placentation in first half of pregnancy → placental ischaemia

Abnormal placentation and trophoblast invasion → poor implantation in underlying microvascular disease, or under-perfusion of large placenta, diabetes, or multiple pregnancy

Lack of vascular adaptation to pregnancy - placenta unable to optimise blood supply from maternal uterine vessels

• Spiral arterioles fail to adapt to become high capacitance, low-resistance vessels

Question 3

What are the symptoms of pre-eclampsia?

Answer 3

Generally asymptomatic, detected by routine screening:

• SBP>140mmHg, DBP>100mmHg - at least 2 readings
• 300mg of protein in 24hr urine sample

Headache, visual disturbance, epigastric pain, vomiting, oedema

Question 4

What are the effects of pre-eclampsia on the body?

Answer 4

Decreased GFR, proteinuria, increased serum creatinine, oliguria

Hyperuricaemia from placental ischaemia, reduced plasma volume, haemoconcentration, abnormal liver function, thrombocytopaemia

Question 5

What are the eventual complications of pre-eclampsia if not treated immediately?

Answer 5

Eclampsia (convulsions)

• LoC, tongue biting, incontinence
• Epilepsy drugs not suitable as different mechanism (not electrical discharge)
  
  • May be due to vascular effect (like migraine) so severe pre-eclamptics given magnesium sulphate prophylactically

HELLP syndrome - combined liver and blood clotting disorder (Haemolytic anaemia, Elevated Liver enzymes, Low Platelets)

Stroke

Intra-uterine growth restriction

Question 6

What are the risk factors for pre-eclampsia?

Answer 6

Previous pre-eclampsia

hypertension

Diabetes

Autoimmune diseases

Thrombophilias - Factor V leiden

Renal disease

Question 7

What is gestational hypertension?

Answer 7

It is a temporary diagnosis if chronic hypertension/pre-eclampsia not given.

Question 8

How does BP change with normal pregnancy?

Answer 8

It initially drops, before rising as placenta is low resistance organ. In pre-eclampsia, the initial drop is less/non-existent

Question 9

What is HELLP syndrome?

Answer 9

Haemolytic Anaemia

Elevated Liver enzymes

Low platelets

Occurs in 20% of patients with severe pre-eclampsia

Test AST/ALT, FBC, clotting times

Can → DIC

Question 10

What investigations are done for pre-eclampsia?

Answer 10

BP, Proteinuria

USS for foetal status

Doppler - lower rate of blood flow in diastole, absent/reverse backflow = fetal stress about to begin

Uric acid: 32 weeks >0.34 = abnormal

Question 11

What is the management of pre-eclampsia?

Answer 11

Prophylaxis = aspirin, antioxidants (reduce oxidative stress)

Magnesium sulphate - though can cause NM blockage, loss of reflexes, double vision, slurred speech, respiratory depression, cardiac arrest

Delivery = cure

If pre-eclampsia resolves before delivery, consider intra-uterine death

Question 12

What are the drugs for treating pre-eclamptic hypertension? 1st, 2nd, 3rd line

Answer 12

1. Labetalol
2. Nifedipine, Hydralazine
3. A-blockers

And dexamethasone (high dose steroids) given in 2 doses - given in case baby needs to be delivered

Question 13

What is the pathophysiology of Hypertension in Pregnancy?

Answer 13

Vasodilation → initial decrease in BP, which rises after 24 weeks