[Pre-eclampsia screening in first and second trimester].

Pre-eclampsia is a pregnancy-associated disease of the second part of the pregnancy, occurring mainly after 20th weeks gestation. The prevalence of hypertension in pregnancy is between 5 to 11% and affects mainly women under 20 years of age. An inadequate invasion of trophoblasts with consequential placental ischemia as a result of insufficiently dilated uterine spiral arteries is thought to be an initial cause in the pathogenesis of pre-eclampsia.