Rates of fetal alcohol spectrum disorders (FASD) among first grade children in a representative middle-class community in the Midwest are substantially higher than most previous estimates for the general populations of the United States, Europe, or Canada, according to results from a study published in the November issue of Pediatrics.

Using three techniques to estimate prevalence, the investigators determined that between six and nine children per 1000 have fetal alcohol syndrome in this community cohort of school children, and 11 to 17 per 1000 children have partial fetal alcohol syndrome. The total prevalence rate for FASD is 24 to 48 children per 1000, write Philip A. May, PhD, from the Department of Nutrition, Gillings School of Global Public Health, Nutrition Research Institute, University of North Carolina, Chapel Hill, and colleagues.

They note that these estimates are substantially higher than most estimates for the general population in the United States. For example, the Centers for Disease Control and Prevention and the Institute of Medicine estimate a rate of 0.2 to 1.5 per 1000 children and 0.5 to 3.0 per 1000 children for fetal alcohol syndrome, respectively.

Dr May and colleagues used active case ascertainment methods to determine the prevalence and characteristics of FASD among first grade children in a representative Midwestern community.

The study considered the continuum of FASD, which includes four diagnoses: fetal alcohol syndrome, partial fetal alcohol syndrome, alcohol-related neurodevelopmental disorder, and alcohol-related birth defects.

Prior studies estimating the prevalence of FASD in the US general population largely relied on passive methods, such as surveillance or clinic-based studies, to estimate prevalence, and it is thought that these passive methods have underestimated the rates of FASD.

For this study, the researchers chose to use active case ascertainment methods in the current study based on the success of these methods to determine minimal prevalence of FASD in countries such as Italy, Croatia, and South Africa.

The study included a cohort of first graders enrolled in public and private schools in a representative Midwestern city. Of the 2033 children in the 32 schools enrolled in the study, 70.5% provided consent to participate. From these children, an oversample of small children (ie, those in the 25th percentile or lower category on height, weight, and head circumference) and randomly selected control candidates were examined, using active case ascertainment methods. These methods included an examination of physical growth, development, dysmorphology, cognition, and behavior.

Investigators also interviewed the children's mothers to determine maternal risk.

The study found that total dysmorphology scores significantly differentiated fetal alcohol syndrome from partial fetal alcohol syndrome, and fetal alcohol syndrome and partial fetal alcohol syndrome from control patients. Children diagnosed with fetal alcohol syndrome were lighter, shorter, and had smaller heads than other children. Children diagnosed with FASD did significantly worse on cognitive and behavioral tests and measures.

Of the four diagnostic groups, it was not possible to clearly differentiate children with alcohol-related neurodevelopmental disorders from other participants.

"Children who have FASD, especially those who have [fetal alcohol syndrome] and [partial fetal alcohol syndrome], can be readily identified in mainstream school populations in the United States," the authors conclude.

When looking at maternal risk factors, the study found that late recognition of pregnancy, quantity of alcohol consumed 3 months before pregnancy, and quantity of drinking reported by the child's father were the most predictive of a child's diagnosis.

The researchers note several limitations, including that they were able to test only 65% of the children they asked to test and only 53% of the mothers asked consented to an interview.

This project was funded by the National Institutes of Health and the National Institute on Alcohol Abuse, and Alcoholism. The authors have disclosed no relevant financial relationships.

Pediatrics. 2014;134:855-866.