¹Hacettepe Üniversitesi, Eczacılık Fakültesi, F.Toksikoloji Anabilim Dalı, Sıhhiye Yerleşkesi Ankara 06100 Türkiye DOI : 10.12991/mpj.20162059818 Pregnancy is a physiological period that meets the requirements of developing and growing fetus in uterus. Almost every pregnant woman is exposed to medicines during pregnancy. The most sensitive period during pregnancy for the chemical exposure is organogenesis when the cell division and differentiation rate are extremely high. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed during pregnancy to treat fever, pain and inflammation. NSAIDs may have significant teratogenic effects on fetus. Increased risks of miscarriage and malformations are associated with NSAID use in early pregnancy. Exposure to NSAIDs after 30 weeks" of gestation is associated with an increased risk of premature closure of the fetal ductus arteriosus and oligohydramnios. Fetal and neonatal adverse effects affecting the brain, kidney, lung, skeleton, gastrointestinal tract and cardiovascular system have also been reported with prenatal exposure to NSAIDs. NSAIDs should be taken during pregnancy only if it is essential at the lowest effective dose and for the shortest duration possible. This review focus on the detail about placental transfer and metabolism of NSAIDs, and the adverse impact of prenatal NSAID exposure. Keywords : Nonsteroidal antiinflammatory drugs (NSAIDs), Pregnancy, Teratogen, Organogenesis