Prenatal Screening and the Reduction of Birth Defects in Populations

OBJECTIVES: Birth defects occur in populations in 3-5% of births. This paper assesses whether population-wide screening programmes for pregnant women would be likely to result in major decreases in the prevalence of birth defects. METHOD: Relevant literature on this question is reviewed and synthesized. RESULTS: Given certain assumptions, a decrease from 3-5 to 2-4% in the prevalence of defects at birth may be possible. The resources required to put in place an appropriately delivered programme to achieve this are substantial. CONCLUSIONS: As well as the potential benefit of a decrease, there are opportunity costs, and potential serious harms. Unless undertaken in a carefully planned and monitored way, a population-based birth defects reduction programme is likely to bring harm and anxiety rather than benefit.