Evolution of the Clinical Diagnostic Criteria for Fetal Alcohol Spectrum Disorders and Application of These Criteria in an Epidemiologic Study of Prevalence

Introduction: Since the first recognition of the Fetal Alcohol Syndrome as a distinct disorder over 40 years ago, it has become clear that there is a broad range of prenatal alcohol effects that include the full-blown Fetal Alcohol Syndrome, but also encompass a much wider spectrum of physical and developmental effects.  Our understanding of what defines Fetal Alcohol Spectrum Disorders continues to evolve.  At the same time, knowledge of the specific clusters of dysmorphological features and patterns of neurobehavioral impairment that are necessary or sufficient to support a clinical diagnosis somewhere on the spectrum is also evolving.  

Methods: Epidemiologic studies of FASD can help inform clinical diagnostic criteria, particularly when population-based samples are utilized to estimate the background rates of physical features and neurobehavioral impairments in an unselected group of unexposed children.  However, such studies also require that a priori decisions be made about which criteria can feasibly be applied in an epidemiologic research study as opposed to a clinical setting, weighing the consequences of both false positives and false negatives. 

Results: Within the CoFASP consortium, a team of dysmorphologists, epidemiologists, and psychologists have worked together to adapt currently available diagnostic schema for practical application in a research setting across cross-sectional samples of several thousand race/ethnically diverse children in four U.S. cities. 

Conclusions: Using the revised IOM criteria as described by Hoyme et al that was initially intended to guide clinical evaluations for FASD, an operational set of definitions for FAS, pFAS, and possible ARND has been established by the CoFASP consortium.  These research algorithms have been applied to data collected from a single standardized physical examination typically conducted in a school setting, combined with data from a one-time administration of a battery of standardized neurobehavioral tests administered in a school setting, and information from a single retrospective interview regarding maternal patterns of alcohol consumption during and surrounding the index pregnancy.  The approach to developing these research criteria, and how they can reasonably be translated to plausible population-based prevalence estimates of FASD in the U.S. will be described.