Chronic Hypertension in Pregnancy

For women with chronic hypertension, it is recommended to initiate daily low-dose aspirin (81 mg) between 12 weeks and 28 weeks of gestation (optimally before 16 weeks) and to continue this therapy until delivery. (A)

Initiation of antihypertensive therapy is recommended for persistent chronic hypertension when systolic pressure is 160 mm Hg or more, diastolic pressure is 110 mm Hg or more, or both. In the setting of comorbidities or underlying impaired renal function, treating at lower blood pressure thresholds may be appropriate. (B)

For the long-term treatment of pregnant women who require pharmacologic therapy, labetalol or nifedipine are reasonable options and are recommended above all other antihypertensive drugs. The use of angiotensin-converting-enzyme inhibitors, angiotensin receptor blockers, renin inhibitors, and mineralocorticoid receptor antagonists is generally not recommended. (B)

Antihypertensive treatment should be initiated expeditiously for acute-onset severe hypertension (systolic blood pressure of 160 mm Hg or more or diastolic blood pressure of 110 mm Hg or more, or both) that is confirmed as persistent (15 minutes or more). The available literature suggests that antihypertensive agents should be administered within 30–60 minutes. However, it is recommended to administer antihypertensive therapy as soon as reasonably possible after the criteria for acute-onset severe hypertension are met. (B)

For women with chronic hypertension and with no additional maternal or fetal complications supporting earlier delivery,

• if not prescribed maintenance antihypertensive medications, delivery before 38 0/7 weeks of gestation is not recommended.
• if prescribed maintenance antihypertensive medications, delivery before 37 0/7 weeks of gestation is not recommended.

(B)

Women with severe acute hypertension that is not controlled with traditional chronic antihypertensive regimens or women who develop superimposed preeclampsia with severe features should be delivered upon diagnosis at 34 0/7 weeks of gestation or more. Because of the significant maternal–fetal and maternal–neonatal morbidity, immediate delivery after maternal stabilization is recommended if any of the following are present at any gestational age in women with superimposed preeclampsia: uncontrollable severe hypertension, eclampsia, pulmonary edema, disseminated intravascular coagulation, new or increasing renal insufficiency, placental abruption, or abnormal fetal testing. (B)

Women who develop superimposed preeclampsia with severe features before 34 0/7 weeks of gestation may be candidates for expectant management under certain circumstances, although expectant management is not recommended beyond 34 0/7 weeks of gestation. In these cases, inpatient management is recommended and should be undertaken only at facilities with adequate maternal and neonatal intensive care resources. (B)

A woman with chronic hypertension should be evaluated prepregnancy to identify possible end-organ involvement, to consider evaluation for secondary hypertension, and for the optimization of maternal comorbidities (eg, obesity, diabetes) before pregnancy. (C)

It is recommended to maintain blood pressure levels for pregnant women with chronic hypertension treated with antihypertensive medications at or above 120 mm Hg but below 160 mm Hg systolic and at or above 80 mm Hg but below 110 mm Hg diastolic. (C)

Antenatal fetal testing is recommended for women with chronic hypertension complicated by issues such as the need for medication, other underlying medical conditions that affect fetal outcome, any evidence of fetal growth restriction, or superimposed preeclampsia. (C)

The risks of fetal growth restriction in patients with chronic hypertension warrant third-trimester ultrasound assessment of fetal growth, with subsequent evaluation as appropriate. (C)

In cases of diagnostic uncertainty in discriminating transient blood pressure increases in chronic hypertension from superimposed preeclampsia, particularly with severe-range blood pressures, initial surveillance in the hospital setting is recommended. Work-up should include evaluation of hematocrit, platelets, creatinine, and liver function tests as well as assessment of new-onset proteinuria. Serum uric acid may be a helpful marker. Elevated hematocrit (indicating hemoconcentration), thrombocytopenia, hyperuricemia, new-onset or worsening proteinuria, elevated serum creatinine, and elevated liver transaminases are more indicative of preeclampsia than chronic hypertension, and, from a practical point of view, the practitioner should think preeclampsia first. Fetal well-being should be assessed as appropriate with fetal heart rate monitoring and sonography. Often, serial blood pressure assessment during 4–8 hours can be helpful in discriminating acute and serious increases in blood pressure from transient hypertension. (C)

In women with superimposed preeclampsia without severe features and with stable maternal and fetal conditions, expectant management until 37 0/7 weeks of gestation with close maternal and fetal surveillance is suggested. (C)