Hypertension in Pregnancy

Question 1

What are the normal patterns of blood pressure in pregnancy?

Answer 1

Falls in the first trimester (particularly the diastolic) and continues to fall until 20-24 weeks.
Then rises to pre-pregnancy levels by term.

Question 2

What is hypertension in pregnancy defined as?

Answer 2

systolic > 140 mmHg or diastolic > 90 mmHg
or an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic

Question 3

What is pre-existing hypertension and who is it more common in?

Answer 3

A history of hypertension before pregnancy or an elevated blood pressure > 140/90 mmHg before 20 weeks gestation

No proteinuria, no oedema

Occurs in 3-5% of pregnancies and is more common in older women

Question 4

How is pre-existing hypertension treated in pregnancy?

Answer 4

ACEi and ARBs should be stopped immediately. Switch to oral labetalol while awaiting specialist review.

Question 5

What is pregnancy-induced hypertension and how common is it?

Answer 5

Hypertension (as defined above) occurring in the second half of pregnancy (i.e. after 20 weeks)

No proteinuria, no oedema

Occurs in around 5-7% of pregnancies

Question 6

How is pregnancy-induced hypertension treated?

Answer 6

Managed with oral labetalol or oral nifedipine (if asthmatic) with hydralazine.

Resolves following birth (typically after one month). Women with PIH are at increased risk of future pre-eclampsia or hypertension later in life

Question 7

What is pre-eclampsia and how common is it?

Answer 7

Pregnancy-induced hypertension in association with proteinuria (> 0.3g / 24 hours)

Oedema may occur but is now less commonly used as a criteria

Occurs in around 5% of pregnancies

Question 8

How are women at risk of developing hypertension in pregnancy managed?

Answer 8

Women who are at high risk of developing pre-eclampsia should take aspirin 75mg od from 12 weeks until the birth of the baby.