1. Hypertensive Disorders of Pregnancy - Dr Thomas Carins
Australian South Asian Healthcare Association (ASHA)
Maternal Health Education Program

2. Hypertensive Disorders
Hypertensive disorders affect 3 – 5% of pregnancies
Chronic Hypertension
Hypertension arising prior to 20 weeks
Gestational Hypertension
Hypertension arising after 20 weeks without end-organ dysfunction
Preeclampsia on chronic hypertension
Systemic features of preeclampsia developing after 20 weeks in a person with chronic hypertension

3. Hypertensive Disorders
Preeclampsia
Hypertension arising after 20 weeks accompanied and one of:
Renal – low urine output, proteinuria (PCR >30mg/mmol)
Haematological – low blood count, low platelet count
Hepatic – severe epigastric pain, elevated liver enzymes
Neurological – seizures, hyper-reflexia, stroke, visual changes
Pulmonary oedema
Fetal growth restriction
Placental abruption

4. New Onset Hypertension
If hypertension develops after 20 weeks:
Usually requires multiple BP measurements over hours
Assess for symptoms of preeclampsia
Headache, RUQ pain, visual disturbances, nausea and vomiting, reduced fetal movements
Investigations that can take place at hospital:
Blood tests (kidney/liver function, full blood count)
Urine dipstick (2+ protein)
US/fetal heart rate monitoring

5. Chronic Hypertension Hypertension
Mild: /90-99 mmHg
Moderate: / mmHg
Severe: >160/110 mmHg
Difficult to diagnose if woman has not presented prior to 20 weeks
Treatment reserved for moderate-severe HTN:
Methyldopa 250mg-500mg TDS
Labetalol mg TDS
Nifedipine 20-60mg (XR) daily

6. Gestational Hypertension
Risks of hypertension
Small babies
Risk of post-partum haemorrhage
Risk of haemorrhagic stroke
Poor neonatal outcomes

7. Preeclampsia One of the leading causes of maternal death
50% of women with gestational hypertension develop preeclampsia
No single cause identified. Due to a defect in placental development which then causes systemic changes leading to end organ damage
For women with a previous history of preeclampsia or current essential hypertension: low dose aspirin throughout pregnancy should be given (100mg daily) to prevent preeclampsia.

8. Active Management Delivery of placenta is the only cure
Severe headache, visual disturbances, hyper-reflexia
All indicate impending seizure!
Severe Preeclampsia necessitates transfer to hospital
Prevent seizures
Lower blood pressure
Deliver

9. Antihypertensives Tight control risks small babies
Poor control risks intra-cerebral haemorrhage
During acute treatment must have fetal heart rate monitoring
Drug
Dose
Route
Protocol
Labetolol
25 – 50 mg
IV bolus over 2 mins
Repeat mins PRN
Nifedipine
10 – 20 mg
Oral
Repeat >45 mins PRN
Hydralazine
5 – 10 mg
IV bolus
Repeat after 30 mins

10. Magnesium Sulphate Most effective method in preventing seizures
Indications:
Severe preeclampsia
Severe headache
Visual disturbances
Severe RUQ pain
Clonus >3 beats
HELLP syndrome (haemolysis, elevated liver enzymes, low platelets)
Loading: 4-6g in 100ml normal saline over 20 mins
Maintenance: 1-3 g/hr

11. Eclampsia Grand mal seizure from 60-90 seconds
1.6–10 / live births
Requires immediate attention. Most self-resolving but require monitoring of airway and vital signs.
May or may not:
Precede severe preeclampsia
Hypertension
Post-partum

12. Eclampsia Management Does not respond to anti-convulsants (Diazepam)
It is not cerebral in nature
Treatment
DRS ABCD
Prevent maternal injury
MgSO4: If already infusing, giver further 2g bolus
Stabilise and deliver: Does not necessarily require caesarean section

13. References
Majority of advice from Advanced Life Support in Obstetrics (ALSO) Asia Pacific.
Obstetrics and Gynaecology: An evidence based guide. Abbott et al 2005.