Hypertensive disorders in pregnancy
Hypertensive disorders of pregnancy occur in approximately 10% of pregnant women and preeclampsia in approximately 3% of pregnancies in the United States (1). The American College of Obstetricians and Gynecologists Task Force on Hypertension in Pregnancy defined chronic hypertension as a systolic blood pressure of 140 mmHg or more or a diastolic blood pressure of 90 mmHg or more on two separate occasions at least 2 h apart occurring before pregnancy or developing less than 20 weeks during pregnancy (2). Mild hypertension is a systolic blood pressure of 140 to 149 mmHg or a diastolic blood pressure of 90 to 99 mmHg (3). Moderate hypertension during pregnancy is a systolic blood pressure of 150 to 159 mmHg or a diastolic blood pressure of 100 to 109 mmHg (3). Severe hypertension during pregnancy is a systolic blood pressure of 160 mmHg or higher or a diastolic blood pressure of 110 mmHg or higher (3). Gestational hypertension occurs after 20 weeks during pregnancy (2). Preeclampsia is diagnosed if the woman has hypertension after 20 weeks of pregnancy with proteinuria greater than 300 mg in a 24-hour urine collection or a urinary protein/creatinine ratio ≥0.3 (2). Severe features of preeclampsia include thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, and cerebral or visual symptoms (2). Modifiable risk factors for hypertensive disorders in pregnancy include increased body mass index, anemia, increased dietary sodium, and decreased dietary potassium intake (4,5).