The field of mother to child transmission of human-immunodeficiency virus is rapidly evolving. In the United States, prevention focuses on implementation of universal human-immunodeficiency virus testing to assure compliance with recommended treatment regimens and infant-feeding strategies. In most cases, this is the avoidance of all breastfeeding. In developing countries, avoidance of breastfeeding places infants at higher risk of morbidity and mortality. Current World Health Organization recommendations require individualized counseling to determine the best feeding method for each woman.