Blood pressure is the amount of force exerted by the blood against the walls of the arteries.
In general, high blood pressure, or hypertension, contributes to the development of coronary heart disease, stroke, heart failure and kidney disease. Although many pregnant women with high blood pressure have healthy babies without serious problems, high blood pressure can be dangerous for both the mother and the fetus. Women with pre-existing, or chronic, high blood pressure are more likely to have certain complications during pregnancy than those with normal blood pressure. The effects of high blood pressure range from mild to severe. High blood pressure can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery.