May PA, et al. - This trial was initiated in order to investigate the prevalence of fetal alcohol spectrum disorders, with the inclusion of fetal alcohol syndrome, partial fetal alcohol syndrome and alcohol-related neurodevelopmental disorder, in 4 regions of the United States. Using a conservative approach, it was determined that the estimated prevalence of fetal alcohol spectrum disorders among first-graders in 4 US communities ranged from 1.1% to 5.0%. The yielded data could reflect more precise US prevalence estimates when compared to previous studies, which possibly was not generalizable to all communities.