Background: Prevention of preeclampsia is very important in reducing maternal and neonatal mortality and morbidity. The purpose of this study was to determine the effectiveness of aspirin in the prevention of preeclampsia in high-risk pregnancies with abnormal findings at uterine artery in doppler ultrasound among women referred to Shabih-Khani hospital in Kashan.

Materials and Methods: In this clinical trial study, women predisposed to preeclampsia at 12-16 weeks of gestation were evaluated by uterine artery doppler ultrasound and in the case of abnormal findings, they were randomly divided into two groups, experimental (n=40) and control (n=40) groups. The experimental group was received aspirin 80 mg/day. Groups were followed up until delivery and pregnancy outcomes (e.g. incidence of preeclampsia, IUGR, preterm labour, 1st and 5th min APGAR less than 5, delivery type and birth weight) were analyzed.

Results: The incidence of preeclampsia in experimental (aspirin) group and control group were 2.5%, 22.5%, respectively. In addition, the risk of preeclampsia was 9 folds more than that of control group (P=0.007). No significant difference was seen between the two groups in the type of delivery, birth weight and gestational age.

Conclusion: Aspirin administration during 12-16 weeks of pregnancy can decrease the incidence of preeclampsia in high-risk pregnancy with abnormal findings of uterine artery as a preventive measure.