Hypertensive Disorders of Pregnancy

Question 1

Define the difference between

• Chronic HTN
• Gestational HTN/ Pregnancy-induced HTN
• Pre-eclampsia
• Eclampsia.

Answer 1

Chronic HTN.

• BP > 140/90
  primary: existing prior to 20weeks
  secondary: due to another cause, ie - hyperaldosteronism, renal parenchymal disorders.

Gestational HTN/PIH

BP > 140/90, after 20 weeks, due to no other cause.

Pre-eclampsia

BP > 140/90.

+ sign of systemic disease (ie, proteinuria).

Eclampsia

Seizures brought on by high ICP in a woman who is pre-eclamptic. Absence of another cause.

Question 2

What are the RF for pre-eclampsia?

Answer 2

Obstetric factors (rejection leading to poor placental development)

• Primiparity + Primipaternity
• Short duration of sexual relationship (antibody dev.)

Conditions leading to ischemia–> poor placental developement:

1. Obstetric factors
   - Multiple pregnancy
   - GDM
2. Social factors:

>35 years.

• Obesity
• Family history
  3. Comorbidities:
• Renal disease
• Antiphospholipid syndrome.
• SLE.

Question 3

What are the systemic effects of Hypertensive Disease of pregnancy and what is their underlying pathophysiology?

Answer 3

Underlying Pathophys:

Defective placental vascular remodeling (weeks 16-22)->inadequate placental perfusion–> release of antiangiogenic factors -> destroys VEGF

Low VEGF -> dysfunctional maternal endothelium -> endothelial damage

-> platelet adhesion + activation of CC.

–> ischemia: kidneys, liver, brain.

Synctiotrophoblast debri -> maternal inflammatory response: leucocytes -> activation of CC, activation of platelets.

Result

General:

• platelet activation + cc activation
• endothelial dysfunction, ischemia at liver, kidneys, brain.

Effects

1. Neurological
   - hyperreflexia w sustained clonus.
   - persistent h/a
   - persistent visual disturbance: photophobia, scotomata.
   - seizures.
2. HELLP
   - haemolysis
   - liver dysfunction + necrosis, swelling + subcapsular haematoma.
   - thrombocytopenia
3. kidneys:
   - glomerular dysfunction
   - proteinuria.
4. Fetus:
   - IUGR
   - placental abruption.

Question 4

What is seen in history and examination in someone with pre-eclampsia?

Answer 4

HISTORY

• headaches (persistent)
• tiredness
• visual disturbances
• urination frequency
• R epigastric pain.
• frequent urination/frothy urine.

EXAM

• high BP
• Abdo: epigastric tenderness, hepatomegaly.
• Uterus: size, fundal height, liquor volume, tone, tenderness - signs of IUGR/placental abruption.
• Neuro exam: hyperreflexia with clonus, visual disturbances.

Question 5

What investigations are done in someone suspected of pre-eclampsia, and what is seen in the results?

Answer 5

BLOODS

1. FBC:
   - Hb: low.
   - Platelets: <100 000 u/L
   2: UEC
   - Creatinine ratio >30.
2. LFT
   - AST>40 u/L
   - ALT >40 u/L
3. Urinalysis: 24 hour urine
   - 0.3g over 24 hour samples.
   - 2+ persistently elevated protein on urine dipstick.

Baby:

• CTG
• US
• Doppler: UA, CA, uterine artery.

Question 6

What is the treatment for pre-eclampsia?

Answer 6

Early: antihypertensive medication

• methyldopa
• labetalol hydrochloride
• nifedipine
• hydralazine

Term:

• delivery.

Question 7

What is the management of a woman in an acute eclamptic attack?

Answer 7

1. Call for help
2. airways - clear airway
3. breathing - check o2 sats.
4. circulation - check cardiac output, insert bore cannula, take bloods (FBC, LFT, UEC, Glucose).
5. Displacement - ensure she is on her left side to prevent IVC compression.
6. Drugs - magnesium sulfate (neuroprotective + vasodilatory effect).

Question 8

What ongoing investigations are done on a woman with pre-eclampsia?

Answer 8

Urinalysis for protein

+ Pre eclampsia bloods

• FBC
• LFTs
• UECs
• creatinine ratio.
• SLE, kidney function, antiphospholipid syndrome, thrombophilias (especially if severe, early onset).