C. Gestational hypertension – Explanation
Hypertension in pregnancy
The classification of hypertension in pregnancy is complicated and varies. Remember, in normal
pregnancy:
- blood pressure usually falls in the first trimester (particularly the diastolic), and continues to fall until
20-24 weeks - after this time the blood pressure usually increases to pre-pregnancy levels by term
Hypertension in pregnancy in usually defined as:
- systolic > 140 mmHg or diastolic > 90 mmHg
- or an increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
After establishing that the patient is hypertensive they should be categorised into one of the following
groups
| Pre-existing hypertension | Pregnancy-induced hypertension (PIH, also known as gestational hypertension) |
Pre-eclampsia |
| 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 |
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 Resolves following birth (typically after one month). Women with PIH are at increased risk of future preeclampsiaor hypertension later in life |
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 |
