Introduction: what do we know of the mechanisms of alcohol damage in utero?

The newly established role of alcohol as a human teratogen important in the aetiology of mental deficiency poses the problem of how maternal ingestion of alcohol damages the developing central nervous system. Two main approaches to the identification of possible mechanisms are suggested: clinical field studies, especially of relatives of affected children, and the use of experimental animal models. The evidence so far provided by each approach, and the limitations of each, are considered. Four possible mechanisms of alcohol-induced damage, originating at different stages of antenatal development, are outlined. These mechanisms are related to the fetal alcohol syndrome, the high incidence of spontaneous abortion or fetal death, retarded fetal growth, and ill-defined behavioural problems in childhood.