Common language for measures of occurrence of congenital anomalies and genetic diseases: Incidence or birth prevalence

Scientists involved in the epidemiology of congenital anomalies (including genetic diseases) use many terms to describe the occurrence of these disorders amongst births, such as 'incidence', 'prevalence' and 'rate'. Yet it is clear that often 'prevalence' is the only meaningful measure for the proportion of births affected with a certain congenital or genetic disorder. 'Incidence' and 'rate' are usually inappropriate, as the assessment of the frequency of a disorder is not a matter of following up a cohort of healthy individuals until they fall ill. Copyright (C) 2000 S. Karger AG, Basel.