Optimising Aspirin Use for Pre-Eclampsia Prevention: The Critical Role of Dose, Timing and Adherence

Abstract

There is abundant evidence that aspirin, commenced at 12 weeks gestation, can be very effective in preventing pre-eclampsia, including preterm pre-eclampsia, preterm delivery and severe pre-eclampsia variants such as HELLP syndrome. However, some clinicians may consider it only modestly effective and neglect its use. Thus, attempts to reduce the morbidity and mortality associated with pre-eclampsia may focus instead on managing its complications, and developing new diagnostics and drugs. Aspirin is hypothesised to improve placental development, either preventing entirely or delaying onset of pre-eclampsia.

The Cochrane review by Duley et al. [1] describes a ‘small-to-moderate’ benefit of aspirin in preventing pre-eclampsia, preterm birth, small-for-gestational age and perinatal death. However, of 34 514 women with individual patient data available, only 9272 were randomised before 16 weeks gestation, and only 5070 received > 75 mg per day. Does the amalgamation of low- and high-doses, with early and late commencement of aspirin give the appearance of lower efficacy, and dissuade clinicians from prioritising aspirin?

In resource-limited contexts, where the likelihood of healthy survival to adulthood is significantly lower for preterm infants [2], the importance of a safe, low-cost intervention such as aspirin is even more important. Underestimation of low-cost, effective interventions such as aspirin may cause considerable harm [2].

This editorial seeks to review the impact of dosage, timing and adherence to aspirin on its efficacy in pre-eclampsia prevention, and explore special considerations for utilisation.