Treatment of Hypertension in Pregnancy

Blood Pressure Thresholds for Treatment

The European Society of Cardiology recommends initiating pharmacological treatment for hypertension in pregnancy with methyldopa, labetalol, or extended-release nifedipine when blood pressure is persistently ≥140/90 mmHg, targeting BP <140/90 mmHg but keeping diastolic BP ≥80 mmHg 1, 2, 3
Initiate antihypertensive medication at BP ≥140/90 mmHg in pregnant women with gestational hypertension (with or without proteinuria), pre-existing hypertension with superimposed gestational hypertension, any hypertension with organ dysfunction or symptoms, or pre-eclampsia 1, 2, 3
For uncomplicated chronic hypertension without the above features, treatment should begin at BP persistently ≥150/95 mmHg 1, 2

Methyldopa has the longest safety record with documented long-term infant follow-up data (7.5 years) and is recommended as a first-line medication for hypertension in pregnancy 5
Labetalol is an effective and safe alternative to methyldopa, with efficacy comparable to methyldopa 5, 3
Extended-release nifedipine has a strong safety profile with once-daily dosing that improves adherence and is recommended as a first-line medication for hypertension in pregnancy 3, 4

Severe hypertension is defined as SBP ≥160 mmHg or DBP ≥110 mmHg and requires hospitalization with urgent treatment 1, 2, 3
Intravenous labetalol is the preferred option for acute management of severe hypertension in pregnancy 4
Sodium nitroprusside should only be used when all other treatments fail due to risk of fetal cyanide poisoning with prolonged use 3

ACE inhibitors, angiotensin receptor blockers (ARBs), and direct renin inhibitors are absolutely contraindicated throughout pregnancy due to severe fetotoxicity, particularly in the second and third trimesters 5, 3, 4

Low-dose aspirin (75-100 mg daily) should be started before 16 weeks gestation in women with history of early-onset pre-eclampsia (<28 weeks) 5, 3
Calcium supplementation of at least 1 gram daily reduces pre-eclampsia risk, particularly in high-risk women 5, 3
Low to moderate-intensity exercise is recommended for all pregnant women without contraindications to reduce risk of gestational hypertension and pre-eclampsia 3

Pre-eclampsia is diagnosed when gestational hypertension is accompanied by proteinuria (>0.3 g/24h or albumin-to-creatinine ratio ≥30 mg/mmol), evidence of maternal organ dysfunction, or uteroplacental dysfunction (fetal growth restriction, abnormal Doppler) 6, 2, 4
Magnesium sulfate should be used for eclampsia and severe pre-eclampsia 6
When pre-eclampsia is suspected, an sFlt-1/PlGF ratio ≤38 can exclude development of pre-eclampsia in the next week 1, 2

Antihypertensive medications should be withdrawn slowly over days, not ceased abruptly, as eclamptic seizures may develop in the early postpartum period 6
NSAIDs for postpartum analgesia should be avoided in women with pre-eclampsia, especially if they have renal disease, placental abruption, or acute kidney injury 6
All women should be reviewed at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized 6
Annual medical review is advised lifelong, as women with gestational hypertension or pre-eclampsia have significantly increased long-term cardiovascular risk 6, 4