Preeclampsia is a disorder associated with pregnancy consisting of hypertension, proteinuria, and new-onset nondependent edema that presents, in most cases, after the 20th week of pregnancy.
Eclampsia is defined as seizure activity in a patient with the presentation described above.
The diagnosis requires 2 such abnormal blood pressure measurements at least 6 hours apart. The etiology of preeclampsia is unknown. However, placental delivery reverses the symptoms of preeclampsia, suggesting that the placenta has a controlling role in the condition. Additionally, women with increased placental tissue for gestational age, such as hydatiform moles and twin pregnancies, have an increased incidence of preeclampsia. In fact, the presence of proteinuric hypertension prior to 20 weeks gestation should initiate a search for molar pregnancy, because it raises the possibility of increased placental tissue for a given gestational age, which could cause the symptoms.