[Hypertensive syndromes in pregnancy. Physiopathology, definition and fetomaternal complications]

A MAJOR CONCERN: Hypertensive syndromes occur in approximately 10 to 15% of all pregnancies and are the cause of 30% of maternal deaths and 20% of fetal and neonatal deaths. Syndromes include gestational hypertension also called pregnancy-induced hypertension, chronic hypertension and preeclampsia.

In pregnant women, hypertension is defined as blood pressure levels above 140/90 mmHg at two successive measurements at a 4-hour interval. The primum movens is the development, at about 16 weeks gestation, of secondary placental ischemia due to a defect in the second trophoblastic invasion of the spiral arteries of the myometrium. This induces endothelial dysfunction leading to pro-coagulation activation and inhibited physiological vasodilatation.

The risk of vasculoplacental disease increases with age, body mass index, primiparity, stressful working conditions, and personal history of vascular events during pregnancy.

Maternal complications include preeclampsia-eclampsia, retroplacental hematoma, acute renal failure, and HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count).

Hypotrophy, in utero death and prematurity may occur. The development of hypertension during pregnancy may also reveal a hypertensive background which could progress to persistent high blood pressure. Preeclampsia is an independent risk factor of cardiovascular disease requiring regular surveillance after delivery.