Pre-eclampsia. III: The role of aspirin in prevention.

Despite optimism generated by earlier, smaller studies, the Collaborative Low-dose Aspirin Study in Pregnancy (CLASP) trial showed that aspirin is not sufficiently effective to recommend its widespread use for the prevention of pre-eclampsia. However, secondary analysis of the CLASP data suggests that aspirin may be effective in reducing the risk of recurrent early onset pre-eclampsia (starting before 32 weeks'gestation). The rationale for low-dose aspirin prophylaxis is the inhibition of synthesis of the prostaglandin thromboxane, which has been been found to be elevated in severe pre-eclampsia. Low-dose aspirin (60 mg per day) is safe for pregnant mothers and their fetuses. Calcium supplementation and fish oil may also reduce the risk of pre-eclampsia, but their use is unproven, and more research is needed on these. Diuretics and dietary salt reduction are not recommended.