Hypertension is the most common medical complication of pregnancy. Isolated and moderate hypertensions most often have an uneventful course. On the contrary, preeclampsia is a severe condition, that threatens the fetal survival, and even maternal prognosis. Recent knowledge demonstrates that preeclampsia is related to a very early defect in placentation, with late maternal systemic effects. This has important practical counterparts. Any manifestation of placental dysfunction should be detected as early as possible. Antihypertensive treatment should be used with great caution, to preserve an appropriate blood flow through a placenta whose hemodynamic resistance is high. Finally, the most appropriate therapeutic way is a preventive one. Cardiovascular risk of those young women should be later monitored.