[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. The clinical symptoms of pre-eclampsia, such as loss of intravascular volume and edema, are caused by generalized endothelial dysfunction. These symptoms are potentiated by hypertension and reduced colloid osmotic pressure in the plama. The organs being affected by pre-eclampsia are those of the vascular-, hepatic-, renal-, cerebral- and coagulatory systems. The prognosis is much more severe when pre-eclampsia develops very early in the pregnancy. The symptoms include elevated blood pressure (over 140 mmHg systolic, 90 mmHg diastolic) combined with proteinuria. Frequent symptoms are hyperreflexia and edema. The etiology of pre-eclampsia has not been clearly defined. Risk factors/triggers for the development of pre-eclampsia can include chronic hypertension, advanced maternal age at first pregnancy (over 35 y), nephropathy, thrombophilia (heterozygous factor V Leiden mutation, antiphospholipid syndrome, heterozygous prothrombin mutation and homozygous MTHFR), multiple gestation and prior pregnancy with preeclampsia. The incidence of preeclampsia is higher in nulliparous than multiparous women. In many countries pre-eclampsia is still most frequent cause of maternal perinatal mortality. HELLP-Syndrome (haemolysis-elevated liver enzyme- low platelets) is a severe progressive course of this disease. Eclampsia, characterized by generalized tonic-clonic convulsion, is the most dangerous complication of pre-eclampsia, and may develop before or after delivery. This form of pre-eclampsia is associated with higher maternal and fetal mortality. Constant maternal hypertension potentially alter vascular integrity of the placenta with further consequences in fetal blood supply leading to growth restriction or zero growth and subsequently resulting in low birth weight or fetal death. The sooner the disease is detected and confirmed, the better the maternal and fetal prognoses are. This is the reason why it is major importance, together with the employment of preventive measures, to identify patients with risk factors with pre-eclampsia though an adequate screening method, thereby detecting the disease earlier and ensuring better pregnancy outcomes for both mother and child.