Methadone maintenance has been used for decades to treat opioid-dependent pregnant women. The outcomes of pregnancies thus treated are vastly improved over the outcomes of pregnancies complicated by street drug use. Despite its long history of successful use during pregnancy, little is known about the long-term effects of methadone on the fetus and the newborn. Studies done in animals suggest there may be subtle effects on brain and behavior. Only recently have other treatments for opioid dependency during pregnancy been investigated. There is increasing evidence that altering the traditional methadone maintenance protocols may be beneficial, and that tapered withdrawal can be safely achieved under some circumstances.