Detecting Fetal Alcohol Syndrome: Incidence And Diagnosis

Fetal Alcohol Syndrome (FAS) is a life-long condition that occurs when a woman consumes any amount of alcohol during pregnancy. It is the most severe condition within a group of conditions called fetal alcohol spectrum disorders (FASDs). FASDs are a group of preventable conditions that can occur when a fetus is exposed to alcohol, causing physical and mental defects that can range from mild to severe. The prevalence of FAS has been a challenging topic for researchers since the 1970s due to difficulties in case finding, sampling, diagnostic criteria, and coordination of interdisciplinary activities. The incidence of FAS, referring to new cases each year, has been estimated to be 0.5 to 2 cases per 1,000 births in the United States during the 1980s and 1990s, with rates varying across different ethnic groups.

The diagnostic criteria for FAS

Fetal Alcohol Syndrome (FAS) is a life-long condition that occurs when a woman consumes any amount of alcohol during pregnancy. FAS is the most severe condition within a group of conditions called Fetal Alcohol Spectrum Disorders (FASDs). FASDs are preventable conditions that can occur when a person is exposed to alcohol before birth.

The facial abnormalities characteristic of FAS include a smooth ridge between the nose and upper lip (called the philtrum), small eye openings, and a thin upper lip. These abnormalities are known as sentinel facial features, and the number required for a diagnosis of FAS varies depending on the diagnostic guidelines used.

Growth deficits are another diagnostic criterion for FAS, though some guidelines have removed this criterion. Growth impairment associated with FAS can occur prenatally, after birth, or both, and can include low birth weight and length, as well as delayed development.

Diagnosing FASDs can be challenging due to the lack of specific medical tests. The diagnostic process typically involves a medical assessment, including a maternal alcohol history, physical examination, and differential diagnosis. The neurodevelopmental assessment is also crucial, evaluating areas such as learning, memory, attention span, communication, vision, and hearing.

It is important to note that FASDs can have lifelong effects, including problems with behavior, learning, and physical development. These effects can range from mild to severe, and individuals with FASDs may require ongoing support and interventions to manage their condition.

Alcohol-related birth defects (ARBD)

ARBDs are physical differences in development that occur when pregnant people drink alcohol. The alcohol passes to the foetus, affecting how it grows. ARBDs do not cause neurological symptoms, but they do affect how the body's organs develop, including the heart, bones, kidneys, vision, or hearing systems. They can be present from birth or become apparent as the child grows.

To diagnose ARBDs, doctors must find differences in a child's physical growth and development, as well as evidence that the birth parent consumed alcohol during pregnancy. If there are no clear signs of ARBDs externally, doctors may perform other tests to determine the presence of ARBDs. An early diagnosis can help children get the care and treatment they need, which may include physical therapy, assistive devices, or surgery.

Determining the incidence of ARBDs and other FASDs can be challenging due to the lack of specific medical tests, such as blood tests. Additionally, FASDs may go undiagnosed or misdiagnosed due to limited information about prenatal alcohol exposure or difficulties distinguishing FASDs from other conditions with similar symptoms, such as ADHD or Williams syndrome.

Alcohol-related neurodevelopmental disorders (ARND)

Fetal Alcohol Spectrum Disorders (FASDs) are a group of preventable conditions that occur when a fetus is exposed to alcohol before birth. FASDs can cause lifelong behavioural, learning, and physical symptoms, and they continue throughout a person's lifetime. However, intervention treatments can help improve development during childhood.

Alcohol-related neurodevelopmental disorder (ARND) is a type of FASD. People with ARND experience cognitive impairments and problems with learning and behaviour due to prenatal alcohol exposure. ARND can cause intellectual disabilities, and those affected may experience difficulties in various areas, including school or work. They may also struggle with regulating their emotions and reactions, leading to problems with impulse control and mood regulation.

The American Academy of Pediatrics outlines specific criteria for diagnosing ARND. While there is no cure for the disorder, early intervention and support are crucial. Social services can provide families with support, including respite care or counselling. Special education services can also help children with ARND reach their potential by providing the necessary tools to manage their condition effectively.

It is important to note that FASDs, including ARND, can be prevented by avoiding alcohol consumption during pregnancy. Alcohol passes from the pregnant person's bloodstream to the fetus through the umbilical cord, interfering with the fetus's brain and central nervous system development. This interference can lead to abnormal physical development, impaired nerve cell functioning, and constricted blood vessels, slowing blood flow to the placenta.

Passive surveillance, clinic-based studies, and active case ascertainment

Passive surveillance studies tend to produce the lowest rates of FAS. This method focuses on large populations in particular geographical or catchment areas, such as schools, towns, and Indian reservations. Local studies that have used passive methods, such as the Metropolitan Atlanta Congenital Defects Program and the Metropolitan Atlanta Developmental Disabilities Surveillance Program, have reported low or modest estimates of FAS prevalence, especially in larger, more urban populations. In Atlanta, researchers found a rate of 1.0 per 10,000 newborns (0.1 per 1,000), which increased to 2.5 per 10,000 (0.25 per 1,000) when including "partial FAS".

Clinic-based studies, on the other hand, tend to produce higher rates of FAS. However, it is important to note that most of these studies have been conducted in publicly funded hospitals and clinics serving predominantly disadvantaged populations. As a result, the data may overrepresent the prevalence of FAS in these specific populations while underrepresenting middle- and upper-class populations. Additionally, since FAS is more accurately diagnosed between the ages of 3 and 12 years, clinic-based studies that focus on newborns may also underestimate the true prevalence of FAS in the studied population.

Active case ascertainment studies actively seek out, find, and recruit children with potential FAS within the population under study. These studies tend to yield the highest rates of FAS, especially when conducted in high-risk populations. For example, a study among Alaska Natives that utilized active case ascertainment methods reported an FAS rate of 3.0–5.2 per 1,000 for the Native population, significantly higher than the rate of 0.2–0.3 per 1,000 in the non-Native population.

By utilizing these different research methods, we can better understand the prevalence and impact of FAS in various populations and work towards prevention and intervention strategies.

Incidence and prevalence of FAS

Fetal Alcohol Syndrome (FAS) is a lifelong condition that occurs when a woman consumes any amount of alcohol during her pregnancy. Alcohol use during pregnancy can interfere with the baby's development, causing physical and mental defects. FAS is the most severe condition within a group of conditions called fetal alcohol spectrum disorders (FASDs). FASDs can have lifelong effects, including problems with behaviour and learning, as well as physical problems.

Determining the prevalence of FAS has proven challenging. Surveillance systems, prenatal clinic-based studies, and special referral clinics have been inadequate for determining the prevalence of FAS or FASD. The often-cited estimates for general populations are believed to be underestimates, and rates from high-risk subgroups cannot be accurately extrapolated to general populations.

The Centers for Disease Control and Prevention (CDC) estimates that FAS occurs at a rate of 0.2 to 1.5 per 1,000 children, while the Institute of Medicine (IOM) estimates are 0.5 to 3.0 per 1,000 children. More current estimates of the prevalence of FAS in the US general population range from 0.2 to 7 per 1,000 children, and 2% to 5% for the entire continuum of FASD.

In a study of first-grade students in a representative Midwestern US community, the prevalence of FAS was found to likely range from 6 to 9 per 1,000 children, with the total rate of FASD estimated at 2.4% to 4.8%. Active case ascertainment methods in schools, including physical examinations, cognitive/behavioural testing, and maternal interviews, have been used successfully to determine the prevalence of FASD in communities in South Africa, Italy, and Croatia.

Globally, the prevalence of FAS in the general population was estimated to be 14.6 per 10,000 people, with one in every 67 women who consumed alcohol during pregnancy delivering a child with FAS. This translates to about 119,000 children born with FAS worldwide every year. The five countries with the highest prevalence of alcohol use during pregnancy are Ireland (60%), Belarus (47%), Denmark (46%), the UK (41%), and the Russian Federation (37%).

Frequently asked questions