Aspirin pre-treatment modulates ozone-induced fetal growth restriction and alterations in uterine blood flow in rats

Prenatal exposure to ozone has been linked to low birth weight in people and fetal growth restriction in rats. Clinical recommendations suggest use of low dose aspirin to lower risk of preeclampsia and intrauterine growth restriction in high-risk pregnancies, yet its utility in mitigating the postnatal effects of gestational ozone ex- posure is unknown. The present study investigated the possibility of low dose aspirin to mitigate the effects of ozone exposure during pregnancy. Exposure to ozone impaired uterine arterial flow and induced growth re- striction in fetuses of both sexes. Aspirin treatment induced marginal improvements in ozone-induced uterine blood flow impairment. However, this resulted in a protection of fetal weight in dams given aspirin only in early pregnancy. Aspirin administration for the entirety of gestation increased placental weight and reduced anti- oxidant status, suggesting that prolonged exposure to low dose aspirin may induce placental inefficiency in our model of growth restriction.