Looking at the data from this superb study, the answer is yes. Not only that, we're likely missing the diagnosis in the vast majority of affected children.
Source: May PA, Chambers CD, Kalberg WO, et al. Prevalence of fetal alcohol spectrum disorders in 4 US communities. JAMA. 2018;319(5):474-482. doi: 10.1001/jama.2017.21896. See AAP Grand Rounds commentary by Dr. Daniel Doherty (subscription required).
Anyone providing medical care to children should be aware of this study, not necessarily the intricate details of study design and statistical analysis, but at least the study's conclusions. It might change the way you think about children with neurodevelopmental problems.
It's an interesting study design, particularly well-suited for fetal alcohol spectrum disorder (FASD), which is diagnosed clinically with no known laboratory studies that are helpful in diagnosis. Over the study period of 2010-2016, the researchers chose 4 communities representing "diverse areas" of the US. Due to confidentiality concerns of the communities and schools involved, the sites were not identified other than specifying general location and size: a Midwest site with 172,000 population, a Southeast with 206,000 people, a Rocky Mountain site with 60,000 people, and a Pacifies Southwest site with a population of 1.4 million. They performed screening assessments for growth and/or development of a little over 6000 first-graders. An additional 585 children underwent a standardized dysmorphology evaluation. Children were judged to have FASD utilizing well-accepted criteria with a slight modification.
Some of the statistical methods are a bit dense for us mere mortals, but the bottom line conclusions are startling. They diagnosed 222 children with FASD, including 27 with full fetal alcohol syndrome, 104 with a partial syndrome, and 91 with alcohol-related neurodevelopmental disorder. Using conservative statistical criteria, they concluded that the prevalence of FASD is 1-5% in these populations. Even more startling than this high rate is the fact that only 2 of the 222 children had been previously diagnosed with FASD. In other words, we might be missing 99% of FASD in our pediatric populations.
The accompanying editorial does a nice job of pointing out the advantages of an active surveillance approach for study of FASD, mentioning 3 advantages: an entire community can be assessed (leading to better representativeness of the results), high probability of accurate diagnosis by utilizing trained specialists, and elimination of self-selection bias that is inherent in any passive surveillance study.
FASD is a preventable disorder, though I acknowledge that changing alcohol consumption patterns is a daunting public health task. Pediatricians and family practitioners should take this opportunity to review the FASD diagnostic criteria mentioned above and work on incorporating careful observation for FASD features in their patients.
