Management of chronic hypertension in pregnancy

ABSTRACT

Chronic hypertension is defined as an elevated blood pressure (BP) that predates conception or is detected before 20 weeks of gestation. It occurs in up to 5% of all pregnancies, and this incidence rate is increasing with the rising prevalence of women who conceive at an older age. Superimposed preeclampsia develops in about 25% of women with chronic hypertension and increases the risks of eclampsia, fetal intrauterine growth restriction, and stillbirth. The management of chronic hypertension remains controversial. According to systematic reviews and meta-analyses, antihypertensive agents are recommended to patients with severe hypertension (systolic BP > or =160 mmHg or diastolic BP > or =105 mmHg). They are not suggested for those with mild hypertension and no evidence of end-organ damage, however, due to the lack of evidence that pharmacologic treatment can improve perinatal outcomes in this population. The optimal BP target is a systolic BP of 120 to 160 mmHg and a diastolic BP of 80 to 105 mmHg. In antenatal care, fetal surveillance should be performed to detect abnormal fetal growth through regular ultrasonography examinations, and in those with fetal intrauterine growth restriction, umbilical arterial Doppler velocimetry should be used. In women at risk of preeclampsia, low-dose aspirin might reduce the possibility of its occurrence. Women with a hypertensive disorder during pregnancy are at increased risk of chronic hypertension, cardiovascular disease, and thromboembolism in later life; therefore, appropriate postnatal BP control and health interventions such as smoking cessation and obesity control should be proposed.