This is one of those things where everyone knew the apparent rates were low, but it was hard to fund research to find out....
Fetal alcohol spectrum disorders may be more widespread in U.S. communities than previously thought, an observational study of 6,600 first-graders suggests.
The active-case ascertainment study, online in JAMA, estimates the prevalence of fetal alcohol spectrum disorders at 1.1% to 5%, reported Christina Chambers, PhD, MPH, of the University of California San Diego, and coauthors.
Weighted, those numbers jump to a range of 3.1-9.8% -- considerably higher than previous prevalence estimates of about 1%.
"We've had spotty estimates of the prevalence of fetal alcohol spectrum disorders in the U.S.," Chambers told MedPage Today. "It is difficult to recognize, so it can be hidden. There may be a stigma associated with it and reluctance on the part of mothers to be forthcoming about alcohol exposure, and on the part of physicians to ask about it."
Fetal alcohol spectrum disorders involve central nervous system damage and physical deficits that stem from prenatal alcohol exposure. The previously accepted prevalence estimate was derived largely from clinic-based studies and passive record surveillance.
Active-case ascertainment -- in which investigators pull data from many sources including site visits -- has been used in other countries and has led to higher prevalence estimates, Chambers explained.
Her group's study evaluated children at four sites in Midwest, Southeast, Pacific Southwest, and Rocky Mountain communities where primary investigators had developed trust. The researchers sampled first-grade students in public and private schools for 2 academic years from 2010 to 2016. Sampling methods and consenting processes varied across sites.