Chronic hypertension during pregnancy

Hypertensive disorders of pregnancy are among the leading causes of fetal and maternal morbidity and mortality. Worldwide, 50 000 to 60 000 women die from pre-eclampsia each year, corresponding to 12% of all maternal deaths.1 2

Pre-gestational hypertension has traditionally been considered a benign and stable condition in pregnant women and has attracted little attention from researchers. A linked systematic review and meta-analysis on chronic hypertension during pregnancy by Bramham and colleagues (doi:10.1136/bmj.g2301) seriously questions this perception and underlines the need for a much more explicit concern.3 The review included 55 studies on chronic hypertension during pregnancy, comprising both observational cohort studies and data from interventional trials from 25 different countries. The authors compared data from studies based on US cohorts with general population incidence obtained from the US National Vital Statistics Report (2006).

Hypertension in pregnancy is usually defined as a blood pressure of 140/90 mm Hg or above and proteinuria as a daily protein excretion of 300 mg or above, a protein:creatinine ratio of 0.3 or above, or 1+ on a urine dipstick.1 However, definitions are inconsistent …