[Preventive low dosage treatment and pre-eclampsia].

Pregnancy-induced hypertension and pre-eclampsia occur in 10% of pregnancies and are recognised as important and prevalent sources of risk to both mother and foetus. Although the exact cause of the disease is unknown, several mechanisms have been suggested, including enhanced sensitivity to vasopressors and imbalance in the production of prostaglandins. This may lead to vasoconstriction of small arteries, activation of platelets and uteroplacental insufficiency. Since thromboxane A2 and prostacyclin are derived from arachidonic acid through the action of cyclooxygenase, low dose aspirin selectively inhibits the synthesis of platelet thromboxane A2 without affecting production of endothelium-derived prostacyclin. Data available from clinical trials suggest that, when given to high risk patients, low dose aspirin reduces risk of preeclampsia and intrauterine growth retardation by 50%, with no observed risk of adverse effects to either mother or foetus.