The problem of perinatal transmission of HIV infection was first appreciated in 1982. In 1991, the Institute of Medicine (IOM) recommended a policy of routine counseling and offering testing (with specific informed consent) for HIV infection to all pregnant women. Since 1991, there have been major advances in the treatment of HIV infection, including demonstration in 1994 of the efficacy of zidovudine to reduce perinatal transmission. The U.S. Public Health Service subsequently issued guidelines for use of zidovudine to reduce perinatal transmission and for counseling and voluntary testing fo...