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

Abstract

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.

Definition: 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.

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

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

Fetal risks: 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.