[Arterial hypertension and pregnancy: diagnostic criteria and therapeutic approach]

Arterial hypertension is a relatively common complication of pregnancy, affecting about 10% of all normal pregnancies. The American College of Obstetric and Gynecology established in 1972 four different forms of arterial hypertension during pregnancy: a) arterial hypertension related to pregnancy, the so-called pre-eclampsia; b) arterial hypertension unrelated to pregnancy or chronic arterial hypertension; c) Pre-eclampsia superimposed on chronic arterial hypertension, and d) Transient or late arterial hypertension (third trimester). Pre-eclampsia and arterial hypertension are two different illnesses with different approaches and treatments. The mechanisms involved in arterial hypertension and pre-eclampsia of pregnant women are presently very well known, including genetic causes, alterations on the renin-angiotensin system, imbalance between vasoconstrictor and vasodilator agents derived from endothelial activity of the spiral arteries of the placenta, such as; prostacyclins, thromboxane A2, nitric oxide, endothelin-1, etc. The placenta is the key factor in inducing pre-eclampsia, and its expulsion during delivery or cesarean section is the definite cure of the process. All hypertensive forms during pregnancy increase the risks on both the mother and the fetus. Maternal risk is based on renal, metabolic and haematologic disorders, leading in some cases to cerebral haemorrhage or hepatic rupture. In the fetus, pre-eclampsia significantly increases the risk of still-birth, abruptio placentae, hypocalvaria, intrauterine growth retardation, and prematurity. Clinical, biochemical and haematologic manifestations of pre-eclampsia are very typical, facilitating an early and easy diagnosis.