The FDA is aware that there are potential adverse health effects with use of marijuana in pregnant or lactating women. Published scientific literature reports potential adverse effects of marijuana use in pregnant women, including fetal growth restriction, low birth weight, preterm birth, small-for-gestational age, neonatal intensive care unit (NICU) admission, and stillbirth. [1, 2, 3] Based on published animal research, there are also concerns that use of marijuana during pregnancy may negatively impact fetal brain development. [4, 5, 6 ] The American College of Obstetricians and Gynecologists (ACOG) recommends that women who are pregnant or contemplating pregnancy should be encouraged to discontinue marijuana use. In addition, ACOG notes that there are insufficient data to evaluate the effects of marijuana use on breastfed infants; therefore, marijuana use is discouraged when breastfeeding.  Pregnant and lactating women should talk with a health care provider about the potential adverse health effects of marijuana use.