The concept that endothelial cell activation and injury constitutes th
e key pathogenetic event is receiving increasing support, but the caus
ative factor or factors are, as yet, unclear. The search for a reliabl
e and clinically useful test to identify pregnant women at risk contin
ues. No definitive conclusions can yet be drawn as to the efficacy and
safety of low-dose aspirin prophylaxis. Monitoring of maternal-fetal
condition, careful consideration of maternal and perinatal risks, and
a balanced decision to continue or terminate pregnancy are key element
s of clinical management.