WHAT'S KNOWN ON THIS SUBJECT: Most studies of fetal alcohol syndrome and fetal alcohol spectrum disorders (FASD) prevalence in the general population of the United States have been carried out using passive methods (surveillance or clinicbased studies), which underestimate rates of FASD. WHAT THIS STUDY ADDS:Using active case ascertainment methods among children in a representative middle class community, rates of fetal alcohol syndrome and total FASD are found to be substantially higher than most often cited estimates for the general US population. abstract OBJECTIVES: To determine the prevalence and characteristics of fetal alcohol spectrum disorders (FASD) among first grade students (6-to 7-year-olds) in a representative Midwestern US community. METHODS:From a consented sample of 70.5% of all first graders enrolled in public and private schools, an oversample of small children (#25th percentile on height, weight, and head circumference) and randomly selected control candidates were examined for physical growth, development, dysmorphology, cognition, and behavior. The children's mothers were interviewed for maternal risk. RESULTS:Total dysmorphology scores differentiate significantly fetal alcohol syndrome (FAS) and partial FAS (PFAS) from one another and from unexposed controls. Alcohol-related neurodevelopmental disorder (ARND) is not as clearly differentiated from controls. Children who had FASD performed, on average, significantly worse on 7 cognitive and behavioral tests and measures. The most predictive maternal risk variables in this community are late recognition of pregnancy, quantity of alcoholic drinks consumed 3 months before pregnancy, and quantity of drinking reported for the index child's father. From the final multidisciplinary case findings, 3 techniques were used to estimate prevalence. FAS in this community likely ranges from 6 to 9 per 1000 children (midpoint, 7.5), PFAS from 11 to 17 per 1000 children (midpoint, 14), and the total rate of FASD is estimated at 24 to 48 per 1000 children, or 2.4% to 4.8% (midpoint, 3.6%). (Continued on last page) CONCLUSIONS:

Objective: To determine the characteristics of children with fetal alcohol spectrum disorders (FASD) and their mothers in a Midwestern city.Methods: Case-control samples were drawn from 2 separate first-grade cohorts (combined N = 4,047) in every city school using different methods. In Cohort Sample 1, all consented small children (≤25th centile on height, weight, and/or head circumference) entered the study along with a random sample from all enrolled students. Cohort Sample 2 was drawn totally at random. Child growth, dysmorphology, and neurobehavior were assessed using the Collaboration on FASD Prevalence (CoFASP) criteria, and mothers were interviewed.Results: For the samples combined, 891 children received dysmorphology examinations, and 692 were case-conferenced for final diagnosis. Forty-four children met criteria for FASD. Total dysmorphology scores differentiated diagnostic groups: fetal alcohol syndrome (FAS), 16.7; partial FAS, 11.8; alcohol-related neurodevelopmental disorder (ARND), 6.1; and typically developing controls, 4.2. Neurobehavioral tests distinguished children with FASD from controls, more for behavioral problems than cognitive delay. Children with ARND demonstrated the poorest neurobehavioral indicators. An adjusted regression model of usual prepregnancy drinking indicated that maternal reports of 3 drinks per drinking day (DDD) were significantly associated with a FASD diagnosis (p = 0.020, OR = 10.1, 95% CI = 1.44 to 70.54), as were 5 or more DDD (p < 0.001, OR = 26.47, 95% CI = 4.65 to 150.62). Other significant maternal risk factors included the following: self-reported drinking in any trimester; smoking and cocaine use during pregnancy; later pregnancy recognition and later and less prenatal care; lower maternal weight, body mass index (BMI), and head circumference; and unmarried status. There was no significant difference in FASD prevalence by race, Hispanic ethnicity, or socioeconomic status at this site, where the prevalence of FASD was 14.4 to 41.2 per 1,000 (1.4 to 4.1%).Conclusion: This city displayed the lowest prevalence of FASD of the 4 CoFASP sites. Nevertheless, FASD were common, and affected children demonstrated a common, recognizable, and measurable array of traits.