Newborn screening is a rapidly developing area driven by both technological advances and public pressure. If they are not yet, all nurses working with mothers and children will soon be involved with implementing newborn-screening programs, and it is therefore important that they appreciate both the benefits and potential harms of such programs. In the United Kingdom, policy regarding the implementation of newborn-screening programs is developed at national level, and consideration of the introduction of new tests is subject to a formalized evaluation framework. In the United States, by contrast, each state develops its own screening program. Knowledge of developments in newborn screening in different countries that have diverse types of healthcare systems helps to inform nurses about the totality of healthcare for newborns, and assists them in becoming more knowledgeable about how international standards differ from those in the United States.