From the Guidelines
Hydralazine is not recommended as a first-line treatment for hypertension in pregnancy due to its association with more perinatal adverse effects compared to other antihypertensive medications. According to the most recent and highest quality study 1, antihypertensive drugs known to be effective and safe in pregnancy include methyldopa, labetalol, and long-acting nifedipine. Hydralazine may be considered in the acute management of hypertension in pregnancy or severe preeclampsia, but its use should be carefully weighed against potential risks.
Key Considerations
- The American College of Obstetricians and Gynecologists recommends controlling blood pressure to 110–135/85 mmHg to reduce the risk of accelerated maternal hypertension and minimize impairment of fetal growth 1.
- Treatment with ACE inhibitors, angiotensin receptor blockers, and spironolactone are contraindicated in pregnancy due to the risk of fetal damage 1.
- Diuretics are not recommended for blood pressure control in pregnancy but may be used during late-stage pregnancy if needed for volume control 1.
Management of Hypertension in Pregnancy
- Methyldopa, labetalol, and long-acting nifedipine are preferred antihypertensive medications for treating hypertension in pregnant women 1.
- Hydralazine may be considered in acute management of hypertension in pregnancy or severe preeclampsia, but its use should be carefully monitored due to potential risks 1.
- Blood pressure should be monitored regularly during treatment, and antihypertensive medications should be used at the lowest effective dose and only when the benefits outweigh potential risks 1.
From the FDA Drug Label
Animal studies indicate that hydrALAZINE is teratogenic in mice at 20 to 30 times the maximum daily human dose of 200 to 300 mg and possibly in rabbits at 10 to 15 times the maximum daily human dose, but that it is nonteratogenic in rats. Teratogenic effects observed were cleft palate and malformations of facial and cranial bones There are no adequate and well-controlled studies in pregnant women. Although clinical experience does not include any positive evidence of adverse effects on the human fetus, hydrALAZINE should be used during pregnancy only if the expected benefit justifies the potential risk to the fetus.
Hydralazine use during pregnancy is considered a Pregnancy Category C medication.
- It may be teratogenic in certain animal species.
- There are no adequate and well-controlled studies in pregnant women.
- The medication should be used during pregnancy only if the expected benefit justifies the potential risk to the fetus 2.
From the Research
Safety of Hydralazine During Pregnancy
- Hydralazine is considered a traditional drug therapy choice for acute reduction of blood pressure in pregnancy 3
- It is recommended for use during pregnancy, with proper monitoring, along with methyldopa and furosemide 4
- A study comparing the efficacy of nifedipine and hydralazine in hypertensive crisis in pregnancy found that both drugs are safe and effective, with nifedipine showing a more rapid onset of action and fewer side effects 5
- Hydralazine is listed as one of the preferred medications to treat hypertension during pregnancy, along with labetalol, nifedipine, and methyldopa 6
- Parenteral hydralazine may be associated with a higher risk of maternal hypotension, but it is not considered teratogenic 7
Key Findings
- Hydralazine is considered safe for use during pregnancy, but it should be used with caution and monitoring due to the risk of maternal hypotension 4, 7
- The choice of antihypertensive medication during pregnancy should be individualized, taking into account the severity of hypertension and the presence of other medical conditions 6
- More research is needed to fully understand the effects of hydralazine on maternal and fetal outcomes during pregnancy 3, 5