The prophylactic use of low-dose aspirin for prevention of preeclampsia has been an important research question in obstetrics for the last three decades. In 1979, Crandon and Isherwood observed that nulliparous women who had taken aspirin regularly during pregnancy were less likely to have preeclampsia than women who did not. In 1985, Beaufils et al published the first randomized trial suggesting that 150 mg aspirin and 300 mg dipyridamole daily from 3 months’ gestation onwards decreased the risk of preeclampsia, fetal growth restriction and stillbirth in high-risk women. Subsequently, more than 50 trials have been carried out throughout the world and a meta-analysis of these studies reported that the administration of low-dose aspirin in high-risk pregnancies is associated with a decrease in the rate of preeclampsia by approximately 10%. Consequently, several national professional bodies recommend that high-risk pregnancies should be treated with aspirin (50–150 mg daily).