SUMMARY: Based on previous studies, a variety of bioenvironmental elements including inappropriate nutrition, diseases, infections, stressors, and medications are involved in epigenetic changes. Drug abuse is one of the most important causes of epigenetic changes and a concern in today’s world. Studies have shown that morphine use by pregnant mothers causes several disorders in mothers in addition to transferring abnormalities to the next generation (placenta and embryo). Epigenetic factors such as morphine cause changes in gene expression in placenta as the first embryonic defense barrier. Because placenta does all the nutritional exchanges between mother’s and embryo’s blood, placental health guarantees normal embryonic development. Many studies have been conducted on defects caused by epigenetic factors including medication use. Opioid abuse including morphine abuse has endangered health of many people. Morphine changes gene expression by binding to opioid receptors on placental villi. Based on the studies, major epigenetic changes due to drug use are mediated by DNA methylation and histone changes. Recognizing different epigenetic factors and their effect on placental and embryonic development is among modern studies. The importance of recognizing epigenetic changes caused by drug abuse by pregnant mothers can be the most important way to prevent adulthood diseases in the embryo and in some cases miscarriage. Changes induced by epigenetic factors can be moderated or reversed by controlling the epigenetic factors. This study is a review of changes caused by morphine use by pregnant rats on development of placenta.
KEY WORDS: Development; Morphine; Embryo; Epigenetic; Pregnancy; Placenta.