“CLASP: A Randomized Trial of Low-Dose Aspirin for the Prevention and Treatment of Preeclampsia Among 9364 Pregnant Women” was a double-blinded, placebo-controlled trial that evaluated the impact of antenatal aspirin administration on development of preeclampsia and intrauterine growth restriction (IUGR). A total of 9364 women either at risk for preeclampsia or currently experiencing preeclampsia or IUGR were enrolled between 12 and 32 weeks and randomized to receive 60mg aspirin daily or placebo. While a nonsignificant 12% reduction in the odds of preeclampsia was found among the entire cohort, the reduction in preeclampsia with aspirin use was more pronounced for those who began prophylaxis prior to 20 weeks (22% reduction, p = 0.06). There was also a lower risk of preterm birth before 37 weeks in those who received aspirin at any time (19.7% vs. 22.2%, p = 0.003) but no difference in IUGR infants. In conclusion, 60mg aspirin daily did not significantly reduce the risk of preeclampsia or IUGR among the women included in this study.
P14.30: The impact of low-dose aspirin on utero-placental circulation: a systematic review