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.
Preeclampsia affects the placenta, and it can affect the mother's kidney, liver, and brain.
Preeclampsia is also a leading cause of fetal complications, which include low birth weight, premature birth, and stillbirth. There is no proven way to prevent preeclampsia. Most women who develop signs of preeclampsia, however, are closely monitored to lessen or avoid related problems. High blood pressure problems occur in 6 percent to 8 percent of all pregnancies in the U.S., about 70 percent of which are first-time pregnancies. In 1998, more than 146,320 cases of preeclampsia alone were diagnosed.