Conditions: Preeclampsia
Keywords: preeclampsia Aspirin
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 104
Healthy volunteers: yes

Brief summary:
This is a randomized controlled trial to estimate the efficacy of low dose aspirin for preventing preeclampsia in women identified as high risk. The investigators hypothesize that the risk of preeclampsia in women identified by a first trimester multiparameter predictive model to be at high risk will be significantly reduced by initiating low dose aspirin early in pregnancy.

Detailed description:
This will be a randomized control trial to estimate the efficacy of low dose aspirin in preventing preeclampsia in women identified in the first trimester to be at high risk. We will also obtain maternal blood, cord blood and placenta specimen for basic science studies to attempt to dissect biological mechanisms of aspirin effects. In addition we will conduct a cost-benefit analysis to determine the cost effectiveness of screening and using aspirin prophylaxis for screen positive women.

Rationale for Design: The randomized control trial is the 'gold standard' of research design. Other designs such as case-control, retrospective cohort and prospective cohort are limited by potential bias and confounding. Randomly assigning subjects to different interventions minimizes selection bias. The random assignment also results in groups that are likely to be similar with regards to important confounding variables. This minimizes confounding by both measured and unmeasured factors. While random allocation does not guarantee the groups will be identical, it does ensure that any differences between them are due to chance alone. Finally, randomization produces groups that are random samples of the population. This permits use of standard statistical tests that are based on probability theory.

Arms:
arm 1: Aspirin 81mg one tablet once a day from recruitment until 37 weeks or labor whichever comes first arm 2: placebo one tablet once a day from recruitment until 37 weeks or labor whichever comes first

Interventions: intervention 1: Aspirin intervention 2: placebo
Intervention descriptions: intervention 1: None intervention 2: None

Protocol document: