Children born to women who abuse drugs have a high risk of being born with birth defects and developmental problems. Methadone is a drug that is commonly used for treating opioid dependence. However, its use by a pregnant woman can cause severe withdrawal symptoms in a newborn because of the prenatal exposure. The purpose of this study is to evaluate the effectiveness of buprenorphine, another drug, versus methadone in reducing withdrawal symptoms in children born to opioid-dependent women.