Chronic hypertension in pregnancy is defined by the American College of Obstetrics and Gynecology (ACOG) as blood pressure ≥140 mm Hg systolic and/or 90 mm Hg diastolic before pregnancy or, in recognition that many women seek medical care only once pregnant, before 20 weeks of gestation, use of antihypertensive medications before pregnancy, or persistence of hypertension for >12 weeks after delivery.