The effectiveness was measured by the following outcomes:
- The number of eligible women who agree to participate in the study.
- How well the protocol for the study is followed
- The number of women in whom it was possible to get first trimester abdominal uterine artery Doppler examination (ultrasound test of blood flow to the uterus)
- The number of women with a completed screening test who are issued the screening result on time
- The acceptability of undergoing a screening test and or of taking Aspirin to women in their first pregnancy
In this study, 500 first time mothers with low risk pregnancies were recruited and randomised to a group. Group 1 received 75mg of Aspirin, group 2 did not receive Aspirin and group 3 received Aspirin until 36 weeks if they had positive early screening.