First-Line Blood Pressure Medications for Pregnant Patients with Hypertension

Extended-release nifedipine and labetalol are the recommended first-line antihypertensive medications for pregnant patients with hypertension. 1

Recommended First-Line Medications

Extended-release nifedipine is often selected as the initial treatment due to its once-daily dosing, which improves patient adherence 1
Labetalol is a reasonable alternative or can be used in combination with nifedipine for patients who experience side effects from nifedipine (such as headaches, tachycardia, or edema) or whose blood pressure remains uncontrolled on a single agent 1
Methyldopa, although historically the first-line agent with the longest safety record and long-term infant outcome data, has fallen out of favor in high-income countries due to its side effect profile (peripheral edema, dry mouth, lightheadedness, drowsiness, mood effects) 1

Advantages: Once-daily dosing improves adherence 1
Note: The long-acting formulation should be used as maintenance therapy during pregnancy, while short-acting formulation is reserved only for rapid treatment of severe hypertension 1
More effective than hydralazine for successful treatment of severe hypertension 2

Dosing may need to be adjusted to three or four times daily due to accelerated drug metabolism during pregnancy 1
Main contraindication is history of reactive airway disease 1
Although there are potential risks such as fetal growth restriction, fetal bradycardia, and hypoglycemia, these risks are minimal with no reports of teratogenicity 1, 3

Dosage: 750 mg to 4 g per day in three or four divided doses 1
Has the best long-term safety record with no evidence of adverse effects in mothers or babies, including long-term pediatric follow-up 1, 4
Still commonly used in low- and middle-income countries where other options may be limited 1

ACE inhibitors, angiotensin receptor blockers (ARBs), direct renin inhibitors, and spironolactone are contraindicated during pregnancy due to risk of fetal damage 1
Atenolol should not be used due to risk of fetal growth restriction 1
Women with pre-existing hypertension should switch from these medications before conception or as soon as pregnancy is confirmed 1

In women with gestational hypertension, pre-existing hypertension superimposed by gestational hypertension, or hypertension with subclinical organ damage or symptoms, drug treatment should be initiated when systolic BP is ≥140 mmHg or diastolic BP ≥90 mmHg 1
In all other cases, treatment should be initiated when systolic BP is ≥150 mmHg or diastolic BP is ≥95 mmHg 1
Target blood pressure should be below 140/90 mmHg but not below 80 mmHg for diastolic BP 1

Systolic BP ≥170 mmHg or diastolic BP ≥110 mmHg in pregnancy is considered an emergency requiring immediate hospitalization 1
Clonidine transdermal patch preparations can be valuable for pregnant patients with hyperemesis who require BP lowering 1
A post-hoc analysis of the CHAP trial (Chronic Hypertension and Pregnancy) found no significant difference in maternal or neonatal outcomes between patients taking labetalol compared with nifedipine 1
Meta-analysis data show that β-blockers and calcium channel blockers are more effective than methyldopa for preventing severe hypertension 1

First-line agents for postpartum hypertension (regardless of breastfeeding status) include nifedipine, amlodipine, enalapril, and labetalol 1
Recent data suggest labetalol may be less effective in the postpartum period compared to calcium channel blockers and may be associated with higher risk of readmission 1
ACE inhibitors (except captopril and enalapril) should be avoided during breastfeeding 1

Avoid sublingual or intravenous nifedipine as rapid and excessive BP reduction has caused myocardial infarction or fetal distress 1
Myocardial depression may occur with combination of calcium channel blockers and intravenous magnesium 1
Diuretics are controversial in pregnancy as they reduce plasma volume expansion, potentially promoting pre-eclampsia, and should only be used in combination with other drugs 1
Despite decades of use, pharmacokinetic data on these medications during pregnancy is limited by heterogeneity in the small number of available studies 5