en پژوهشی اصيل Original Research <strong>Aim(s):</strong> Obesity in pregnant women is a serious health problem that has many complications such as pre-eclampsia and fetal growth restriction (FGR). The aim of the present study was to evaluate the effect of aspirin on prevalence of pre-eclampsia and FGR in obese pregnant women.<br> <strong>Materials & Methods: </strong>This randomized controlled clinical trial was conducted on 187 pregnant women referring to birth center of Mofatteh Clinic, Yasuj University of Medical Sciences, Yasuj, Iran in 2017-2018.<br> The subjects were selected using purposive sampling method and randomly divided into two groups; intervention group (n=89) and control group (n=98). The intervention group received 80mg/day aspirin and the control group received placebo at 13-20 weeks of gestation until 34 weeks of pregnancy. Data were analyzed by SPSS 21 software using Chi square test.<br> <strong>Findings</strong>: The prevalence of pre-eclampsia (1.1 vs. 11.2) and FGR (3.4 vs. 21.4) were significantly lower in the intervention group compared to the control group (p<0.05).<br> <strong>Conclusion</strong>: Administration of 80mg/daily of aspirin from 13-20 weeks of gestation in obese pregnant women reduces the incidence of pre-eclampsia and FGR, which could support the positive role of aspirin in preventing pre-eclampsia and FGR. aspirin,obesity,pregnancy,preeclampsia,fetal growth restriction, 159 164 http://jccs.yums.ac.ir/browse.php?a_code=A-10-104-1&slc_lang=en&sid=1 R. Vanda 10031947532846005507 10031947532846005507 No Gynecology & Obstetrics Department, Yasuj University of Medical Sciences, Yasuj, Iran Sh. Aramesh 10031947532846005508 10031947532846005508 No Gynecology & Obstetrics Department, Yasuj University of Medical Sciences, Yasuj, Iran M. Sadeghian 10031947532846005509 10031947532846005509 No Gynecology & Obstetrics Department, Valiasr Hospital, Bafgh, Iran M.A. Ghatee 10031947532846005510 10031947532846005510 No Cellular & Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran P. Ghaffari pari.ghaffari@gmail.com 10031947532846005511 10031947532846005511 Yes Gynecology & Obstetrics Department, Yasuj University of Medical Sciences, Yasuj, Iran