From the Guidelines
For pregnant women with chronic hypertension, the recommended blood pressure goal is to maintain levels between 110-135/85 mmHg, as this range is associated with reduced risk of accelerated maternal hypertension and minimized impairment of fetal growth 1.
Key Considerations
- The target blood pressure range is based on the most recent evidence from the Control of Hypertension in Pregnancy Study (CHIPS) and other studies, which suggest that maintaining blood pressure within this range can help balance maternal safety with adequate blood flow to the developing fetus 1.
- Medications considered safe and preferred during pregnancy include labetalol, nifedipine extended-release, and methyldopa, while ACE inhibitors, ARBs, and direct renin inhibitors are contraindicated due to fetal risks 1.
- Blood pressure should be monitored regularly, ideally every 2-4 weeks, with more frequent monitoring in the third trimester, to ensure that the target range is maintained and to minimize the risk of complications 1.
Treatment Approach
- Treatment should be initiated or adjusted if blood pressure consistently exceeds the target range, with the goal of reducing maternal risks such as stroke, heart failure, and renal injury while avoiding excessive lowering of blood pressure that might compromise placental perfusion 1.
- Home blood pressure monitoring can be a useful adjunct to clinic visits, but it is essential to ensure that the device is accurate and calibrated correctly 1.
Risks and Complications
- The key risks of chronic essential hypertension in pregnancy include superimposed preeclampsia, fetal growth restriction, and accelerated maternal hypertension, which can be mitigated by maintaining the target blood pressure range and monitoring blood pressure regularly 1.
From the Research
Target Blood Pressure in Pregnancy for Patients with Chronic Hypertension
- The target blood pressure in pregnancy for patients with chronic hypertension is a topic of ongoing debate and research 2, 3, 4.
- According to the American College of Obstetricians and Gynecologists, hypertension in pregnancy is defined as a systolic blood pressure higher than 140 mmHg or a diastolic blood pressure higher than 90 mmHg 3, 5.
- A study published in The New England Journal of Medicine found that targeting a blood pressure of less than 140/90 mmHg in pregnant women with mild chronic hypertension was associated with better pregnancy outcomes than reserving treatment only for severe hypertension 4.
- The CHIPS (Control of Hypertension in Pregnancy Study) trial also evaluated the risks and benefits of tight versus less tight control of blood pressure in nonproteinuric hypertensive women, most of whom had pre-existing hypertension, and found an increased risk of severe hypertension when blood pressure was not tightly controlled 2.
- The optimal blood pressure targets for pregnant women with chronic hypertension are still unclear, but the available evidence suggests that targeting a blood pressure of less than 140/90 mmHg may be beneficial 2, 3, 4.
Key Findings
- Pregnant women with chronic hypertension are at significant risk for maternal and fetal morbidity and mortality 2, 3.
- The incidence of adverse pregnancy outcomes, such as preeclampsia and preterm birth, is higher in women with chronic hypertension than in those without 3, 4.
- Antihypertensive treatment during pregnancy may reduce the risk of adverse pregnancy outcomes, but the benefits and safety of such treatment are still uncertain 2, 4.
- The American College of Cardiology/American Heart Association revised their guidelines for hypertension in the general population in 2017, but the definition of hypertension during pregnancy remains unchanged 3.