HTN in Pregnancy

Question 1

Define HTN in pregnancy

Normal HTN and severe

Answer 1

HTN: SBP > 140mmHg or DBP > 90 mmHg based on > 1 measurement at least 4h apart

Severe HTN: after 2 measurements of SBP > 160 mmHg and/ or DBP > 110 mmHg

Question 2

What are the 4 groups of HTN in pregnancy?

Answer 2

1. Chronic HTN
2. Gestational HTN
3. Preeclampsia
4. Chronic HTN with superimposed preeclampsia

Question 3

Define chronic HTN in pregnancy

Answer 3

Pre-existing HTN or new onset HTN before 20w gestation

Question 4

Define gestational HTN in pregnancy

Answer 4

New onset HTN without proteinuria after 20w gestation

Question 5

Define preeclampsia in pregnancy

Answer 5

New onset HTN after 20w gestation plus new onset of any of the following:
- Proteinuria
- Signs of end-organ dysfunction
- Uteroplacental dysfunction

Question 6

Define chronic HTN with superimposed preeclampsia

Answer 6

New onset proteinuria in a woman with chronic HTN but no proteinuria before 20w gestation

Question 7

Consequence of preeclampsia?

Answer 7

MEDICAL EMERGENCY (risks to both mother and fetus)

May progress rapidly to eclampsia: new onset tonic-clonic, focal or multifocal seizures superimposed on preeclampsia

Question 8

Medication to prevent preeclampsia?

Who is it recommended for?

When should it be given?

Answer 8

Low dose aspirin 100mg or more OD

Recommended for: HTN on previous pregnancy, multifetal gestation, autoimmune diseases, DM, CKD etc

Started between 12-28w (ideally before 16w) and continued until delivery

Question 9

List the Tx options for HTN in pregnancy (MLNHH)

Answer 9

First line:
- Labetalol (common)
- Nifedipine ER (common)

Not first line:
- Methyldope
- Hydrochlorothiazide
- Hydralazine

Question 10

Comment on the use of Methyldopa for HTN in pregnancy

Safety, potency?

Answer 10

• Extensive safety data
• Low potency, increased ADEs (sedation, dizziness etc)

Question 11

Comment on the use of labetalol for HTN in pregnancy

What should we monitor for?

Answer 11

Commonly used in practice.

Monitor for bronchoconstrictive effects, bradycardia

Preferred over other BB as it has less adverse effects on uteroplacental blood flow and fetal growth

Question 12

Comment on the use of Nifedipine ER for HTN in pregnancy

Monitoring?

Answer 12

Commonly used in practice.

Monitor for pedal edema, flushing, headaches

Safe, widely used CCB in pregnancy

Question 13

Comment on the use of Hydrochlorothiazide for HTN in pregnancy

Answer 13

2nd, 3rd line

Concerns for potential interference with normal blood volume expansion during pregnancy

Question 14

Comment on the use of Hydralazine for HTN in pregnancy

Answer 14

Falling out of favour as adverse effects mimic s/sx associated with severe preeclampsia and imminent eclampsia. (n/v, palpitation, flushing, headache, tremor)

Question 15

At what BP threshold should we start Tx for HTN in pregnancy?

Answer 15

Start Tx when BP > 140/90 mmHg