eclampsia, term applied to toxic complications that can occur late in pregnancy. Toxemia of pregnancy occurs in 10% to 20% of pregnant women; symptoms include headache, vertigo, visual disturbances, vomiting, hypertension, and edema. The four categories of hypertension during pregnancy are pre-eclampsia, eclampsia, chronic hypertension, and transient hypertension. Pre-eclampsia, which occurs late in pregnancy, is characterized by decreased cardiac output and increased blood vessel resistance. It may be prevented with calcium supplements and low-dose aspirin, and a cesarian section is often safer than natural childbirth. Only 5% of of women with pre-eclampsia progress to eclampsia, which is accompanied by convulsions and coma. To avoid renal and cardiovascular damage of the mother and to prevent fetal damage, the condition is treated by termination of pregnancy.

Hypertensive conditions unique to pregnancy. Preeclampsia is marked by hypertension, protein in the urine, and hand and face edema, which develop late in pregnancy or soon after. Persistent hypertension compromises the fetus's blood supply and damages the mother's kidneys. Monitoring of blood pressure and weight gain may detect it before symptoms (headaches, visual disturbances, stomach pain) begin. Eclampsia follows in about 5percnt of cases, with convulsions that pose a serious threat to mother and child. It can usually be prevented by special diets, drugs, and limited activity or early delivery.

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