Ethical issues in newborn screening and the impact of new technologies.

Medical ethics is an integral part of medical practice. The general principles are well known: autonomy (the right to choose), beneficence (do good), non-maleficence (do no harm), and justice (be fair and equitable). In newborn screening these principles must be especially carefully applied, as the intervention, screening, has not been sought by the patient, but is a form of preventive medicine. In proposing a screening programme questions to be asked are: should we do it? (is there enough benefit, not too much harm?); can we do it? (do we have the technology and skill to find the cases sought); can we afford it? The first question, with its ethical implications, is often ignored. New issues have arisen with new technology, but underlying ethical themes are the same. Tandem mass spectrometry can be used to detect about 30 very rare disorders in a single test. Proving the benefit of this (and other screening tests) is difficult because randomised controlled trials seem impractical, because of power considerations, long follow-up time, and because there is already a perceived benefit. Best possible evidence of a lower order must be sought. In future, DNA microarray technology is likely to become sufficiently inexpensive to apply to newborn screening. It is difficult to predict all the future possibilities of DNA technology in this fast-moving field. Major ethical problems are likely with the ability to detect adult-onset disorders or susceptibility to these in babies. Under what circumstances would this be ethical? We need to start debating these issues.