Introduction
Hypertension in pregnancy denotes a systolic blood pressure of 140 mmHg or higher and/or diastolic pressure of 90 mmHg or higher on 2 occasions at least 5 minutes apart using an appropriate-sized cuff especially in obese patients.
It is severe when systolic blood pressure is 160 mmHg or higher and diastolic blood pressure is 110 mmHg or higher.
This includes women whose hypertension was diagnosed prior to pregnancy as well as during pregnancy.
Known hypertensives on ACE inhibitors, ARBS and alpha-blockers should be switched to medications considered safe during pregnancy.
Causes of hypertension in pregnancy
- Pregnancy-induced hypertension (no proteinuria)
- Pre-eclampsia (hypertension with proteinuria)
- Eclampsia (hypertension with proteinuria and fits)
- Chronic hypertension (existing before pregnancy)
- Chronic hypertension with superimposed pre-eclampsia, or eclampsia (See ‘Hypertension‘, ‘Pre-eclampsia’ and ‘Eclampsia’)
Symptoms of hypertension in pregnancy
See ‘Hypertension’ for the symptoms of hypertension. Symptoms of hypertension are basically the same including when pregnant.
Signs of hypertension in pregnancy
(See ‘Hypertension’)
Investigations
- FBC
- Clotting profile
- Serum Uric Acid
- BUE and Creatinine
- Urinalysis and culture
- Liver function tests.
- Random blood glucose
- Daily assessment of urine proteins (if patient on admission) Repeated ultrasound scans for close foetal growth monitoring
Treatment for hypertension in pregnancy
Treatment objectives
The treatment objectives of HTN in pregnancy include the following:
- To control blood pressure
- To detect or treat any complications that may arise especially superimposed pre-eclampsia
- To prevent foetal complications
- To deliver a healthy baby
Non-pharmacological treatment
- (See ‘Antenatal Care‘ and ‘Hypertension’)
Pharmacological treatment
A. Hypertension in Pregnancy not associated with pre-eclampsia or eclampsia
1st Line Treatment
Evidence Rating: [A]
Methyldopa, oral,
- 250-500 mg 8-12 hourly (max. 2g daily)
2nd Line Treatment
Evidence Rating: [A]
Nifedipine sustained release, oral,
- 10-40 mg 12 hourly
B. HTN in Pregnancy associated with pre-eclampsia and eclampsia
(See ‘Hypertension’, ‘Pre-eclampsia’ and ‘Eclampsia’)
Referral Criteria
Refer all cases of superimposed pre-eclampsia or other obstetric complication promptly to a hospital or obstetrician after initiation of treatment.