Aspirin and prevention of preeclampsia.

Aspirin is used in pregnant women in order to obviate the imbalance of pros tanoids caused by a defective placentation, and also to counteract the wide spread thrombotic tendency related to endothelial dysfunction. After a serie of controlled trials which showed a very consistent effect of aspirin t prevent preeclampsia and fetal growth retardation. several recen t large trials have cast the doubt, and even unbelief. Their results are an alyzed in an explicative way. Discrepancies seem largely related to either studying very low-risk populations. or strong differences in aspirin dosage and/or term of introduction. In the last few years, several works have sho wn the criticial importance of an early treatment, and also of a measurable biologic effect, which requires larger dosages than those used in the most recent trials. The doubt largely remains as for the adequate indications o f this treatment. New data in the physiology of placentation suggest that i t would be logical to give aspirin as early as the first wave of throphobla stic invasion. The effect of so an early treatment need to be evaluated. Th e search for early markers should be pursued. The combination of aspirin an d heparin is under investigation. Finally, other ways of prevention. such a s anti-oxidants, are also being studied (C) 2000 Editions scientifiques et medicales Elsevier SAS.