How Common Is FAS?

FAS is a completely preventable set of birth defects and neurodevelopmental abnormalities. The prevalence of prenatal alcohol exposure and FAS constitutes a major public health concern.

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It is unknown exactly how many people have Fetal Alcohol Syndrome. The literature on the prevalence, incidence, and epidemiology of FAS, while extensive, is far from consistent or conclusive. It is largely complicated by the wide variation in data collection methodologies that are utilized, as well as differences in the employed diagnostic criteria and disorder outcome definitions. As a result, comparing the incidence, prevalence, and case characteristics of FAS between studies is extremely difficult, if not impossible.

Below are some prevalence estimates according to a recent systematic review and meta-analysis. It is important to understand that these are only the results from one study, and therefore they may not be congruous with other conducted research. The various study methodologies and their resultant prevalence estimates will be discussed later.

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ALCOHOL CONSUMPTION DURING PREGNANCY

• 9.8% of women worldwide consume alcohol during pregnancy

Alcohol use during pregnancy varies widely by geographical location

• 25.2% of pregnant women consume alcohol in the World Health Organization (WHO) European region
• 0.2% of pregnant women consume alcohol during pregnancy in the WHO Eastern Mediterranean region
• Russia has the highest prevalence of alcohol use during pregnancy (36.5%)
• Oman, United Arab Emirates, Saudi Arabia, Qatar, and Kuwait have the lowest prevalence of alcohol use during pregnancy (0%)

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PREVALENCE OF FAS

• 1 in 67 women worldwide deliver a child with FAS
• 14.6 infants per 10,000 births worldwide have FAS
• 119,000 children are born with FAS globally each year

The prevalence of FAS varies widely by geographical location

• 585.3 per 10,000 people have FAS in South Africa, a region with one of the highest rates of FAS and alcohol consumption in the world
• Less than 0.05 per 10,000 people in Oman, United Arab Emirates, Saudi Arabia, Qatar, and Kuwait have FAS

The prevalence of FAS is consistent with the prevalence of alcohol use during pregnancy

• The WHO European region has the highest prevalence at 37.4 cases per 10,000 people
  • This is 2.6 times higher than the reported global average
• The WHO Eastern Mediterranean region has the lowest prevalence at 0.2 cases per 10,000 people 

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Epidemiological Studies of FAS

A variety of approaches have been taken to ascertain the prevalence of FAS, each having a number of advantages and disadvantages. Rates of FAS in several of the most complete studies indicate that there are 0.5 to 3 cases per 1,000 births, which translates to approximately 2000 to 12,000 FAS births per year. The methods that are utilized in these studies can generally fit under the two broad categories of Passive Surveillance and Active Surveillance.

Passive Surveillance involves gathering existing case data of a defined birth defect or syndrome from hospitals, clinics, disease registries, or other medical records. Passive surveillance is the strategy that is generally used to monitor birth defects such as FAS. Epidemiological studies of FAS utilizing passive surveillance are commonly conducted on U.S. and European populations and include:

• Registry-Based Studies
• Clinic-Based Studies

Active Surveillance involves the direct collection of case data to address a specific disease or problem. Studies on FAS that utilize active surveillance include:

• Population-Based Active Case Ascertainment

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PREVALENCE ESTIMATES DERIVED FROM REGISTRY-BASED STUDIES

• 3 out of 10,000 children aged 7 to 9 in the U.S. have FAS according to the most recent CDC study of medical records
• 3.7 of every 10,000 births in the U.S. have FAS according to a national study using hospital discharge data
• 0.0006% to 0.3% of individuals in the North American and European community have FAS according to a study that used birth certificates and medical chart review

Medical records collected from more than 1500 US hospitals revealed FAS prevalence estimates for different ethnicities

• 2.97 per 1,000 for Native Americans
• 0.6 per 1,000 for African Americans
• 0.09 per 1,000 for Caucasians
• 0.08 per 1,000 for Hispanics
• 0.03 per 1,000 for Asians

The CDC’s Birth Defects Monitoring Program revealed an increased prevalence in the U.S. using hospital discharge data

• 0.22 per 1,000 from 1979 to 1993
• 0.37 per 1,000 in 1992
• 0.67 per 1,000 in 1993

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PREVALENCE ESTIMATES DERIVED FROM CLINIC-BASED STUDIES

• 3.3 to 22 cases of FAS per 10,000 people in the U.S
• 9.7 cases of FAS per 10,000 people in the developed world
• 23 cases of FAS per 10,000 people in African Americans of low SES

Clinic-Based studies have reported varying rates of FAS in different countries, and even between U.S. states

• 17 cases of FAS per 10,000 births in Sweden
• 12 cases of FAS per 10,000 births in France
• 13 cases of FAS per 10,000 births in Seattle, WA
• 31 cases of FAS per 10,000 births in Boston, MA
• 30 cases of FAS per 10,000 births in Cleveland, OH

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Pros and Cons of Passive Surveillance

Passive surveillance is relatively inexpensive, making it a desirable option. It allows for the ability to compare the relative rate of FAS with other birth defects, as they use directly comparable methodologies to assess prevalence and incidence. In addition, it can be used to monitor differences by geographic distribution or socioeconomic status.

On the other hand, due to its complex diagnosis, passive surveillance is notoriously inaccurate when used for FAS. The characteristics that are prominent and used for diagnosis may differ by age, and as a result, FAS commonly goes unrecognized at birth. This leads to a gross underestimate of the prevalence of FAS in registry-based studies. In fact, prevalence rates from registry-based studies are approximately 20 times lower than the rates documented in most epidemiological studies

In passive clinic-based studies, the prevalence of FAS varies by the prevalence of the problem in the select population that is served by the hospital or clinic. As a result, the data obtained in these studies typically result in numbers that are higher than prevalence estimates derived from standard surveillance methodologies.

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Rather than using available data like medical charts, this methodology utilizes direct collection of data through experimentally driven protocols. Findings from these studies should generalize to the whole population that is being addressed, not only to those included in the study.

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PREVALENCE ESTIMATES DERIVED FROM POPULATION-BASED ACTIVE CASE ASCERTAINMENT

• 6 to 9 per 1,000 school-aged children have FAS in several U.S. communities according to the CDC
• 1 in 9 pregnant women drank alcohol in the past 30 days in a CDC study
• Globally, 7.7 out of 1000 children and youth have FAS according to a systematic review

One study demonstrated that the prevalence of FAS varies largely in different settings

• 21% of children in foster care have FAS
• 0.36% of children in schools have FAS
• 1.04% of individuals in prisons and correctional facilities have FAS
• 4.9% of children in special education have FAS

Findings from the following Cohort Active Case Ascertainment study are the highest reported rates in any overall community

• 40.5 to 46.4 per 1,000 first grade children in a South African community had FAS in the primary cohort
• 65.2 to 74.2 per 1,000 first grade children in this community had FAS two years later
• 68.0 to 89.2 per 1,000 first grade children in this community had FAS in the third cohort

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Pros and Cons of Active Surveillance

Population-based active case ascertainment studies produce relevant information on the magnitude of a problem in specific communities and can be useful for comprehensive community-based prevention efforts. They detect substantially more cases and allow for control over data collection, which yields more accurate diagnoses and higher quality measurements of prevalence. They also provide the capability to examine a range of social and cultural influences that impact the rates of conditions.

Understandably, the use of active case ascertainment for epidemiological research on FAS is endorsed by the U.S. Insitute of Medicine as the most accurate approach to determining prevalence rates.

Unfortunately, these studies are also logistically challenging, extremely labor intensive, and time consuming. In addition, it is extremely expensive to collect data from a population large enough to produce representative results. In fact, they can be ten times more expensive than studies that utilize passive surveillance methodologies.

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Additional Resources

Centers for Disease Control and Prevention

National Center for Biotechnology Information

The Lancet