There is growing evidence that there is an increased use of Marijuana (cannabis) during the perinatal period. This review summarizes pertinent legislation (past and present) and the physiology and pathophysiology of cannabis use during pregnancy. The literature which involves issues concerning cannabis and pregnancy is expanding but at present has many gaps and unanswered questions. The effects on the newborn are significant and treatment recommendations including breastfeeding are presented. Also included is a description of developmental delay during the first 2 years of life in infants exposed to prenatal marijuana. In addition, this commentary discusses the increase use of the newer "synthetic" cannabinoids which have greater psychotropic activity and can cause significant harm.