Last updated: 18 January 2023 & medically reviewed by Hailey Shafir
Fetal Alcohol Syndrome (FAS) is one of the most common alcohol-related conditions that affect unborn babies exposed in-utero to alcohol. FAS is part of a larger group of alcohol and pregnancy-related issues, commonly grouped as Fetal alcohol spectrum disorders (FASDs). The effects of FASDs can include both physical problems and issues with behavior and learning, or often a combination of all.
- Despite popular opinion, there is no known safe amount of alcohol to consume while pregnant, and any amount of alcohol has the potential to harm an unborn child.
- Alcohol use can cause a wide range of health and birth defects, so each baby can be affected in different ways. The effects of FASD range from mild to severe, with moderate and heavy drinking being more likely to cause severe defects.
- Unlike other medical conditions associated with prenatal defects, there are no medical tests available for FASD conditions. Doctors and other healthcare professionals look for the signs and symptoms of FASD and also rely on self-reported alcohol use from the mother.
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Causes of fetal alcohol syndrome
Like all forms of FASDs, Fetal Alcohol Syndrome is caused by a woman drinking alcohol during pregnancy. All nutrients and toxins ingested by the mother (including alcohol and drugs) pass through the mother's blood and into the unborn child via the umbilical cord. This is why there are such strict health guidelines about what pregnant women should and should not consume when it comes to food, drugs, alcohol, and even prescribed and over-the-counter medications.
Despite popular opinion, there is no known safe amount of alcohol to consume while pregnant, and any amount of alcohol has the potential to harm an unborn child. All types of alcohol including beer, wine, and spirits, can have harmful effects, but high or more potent forms of alcohol are most likely to cause harm.
This is why the American College of Obstetrics and Gynecologists recommend that alcohol consumption cease immediately once a woman discovers she is pregnant. Harmful effects from alcohol can affect unborn babies through all stages of gestation. Continuing to drink (even in low or moderate amounts) greatly increases the risk of fetal alcohol syndrome or other forms of FASD.
*If you are pregnant and are struggling with an alcohol use disorder then contact SAMHSA or another addiction support organization to get help.
Signs and symptoms of fetal alcohol syndrome
Alcohol use can cause a wide range of health and birth defects, so each baby can be affected in different ways. The effects of FASD range from mild to severe, with moderate and heavy drinking being more likely to cause severe defects. Some of the mild, moderate, or severe effects of FASD can include: 
- Low birth weight and small head size
- Problems sleeping and feeding
- Poor coordination
- Poor memory, concentration or learning
- Speech or language delays
- Central nervous system (CNS) problems
- Minor facial feature abnormality
- Growth problems or stunted physical development
- Communication issues
- Behavioral and conduct problems in childhood
- Poor vision or hearing
- Sleep problems
- Problems with organ development (kidneys, heart, lungs, etc.)
- Poorer brain development
Other FASD types and diagnoses
Aside from the more common symptoms associated with fetal alcohol syndrome, there is a range of other alcohol-related disorders that can affect unborn babies. Some of the other FASD’s are listed below.
Alcohol-Related Neurodevelopmental Disorder (ARND): ARND is characterized by intellectual disabilities, behavioral problems, and learning problems. They may do poorly in education compared to their peers and will often struggle with attention, memory, judgment, mathematics, and impulse control.
Alcohol-Related Birth Defects (ARBD): People with ARBD might have problems with the heart, kidneys, or bones or with hearing. They might have a mix of these.
Neurobehavioral Disorder Associated with Prenatal Alcohol Exposure (ND-PAE): ND-PAE is a relatively new FASD condition, first recognized in Diagnostic and Statistical Manual 5 (DSM-5) when it was released in 2013. Much like with ARND and ARBD conditions, children with ND-PAE will exhibit symptoms in three areas: 
- Memory and learning - the child may struggle to retain information or will forget previously learned material, making continuous learning difficult.
- Behavioral problems - the child may display behavioral issues in a number of areas, such as mood swings (including outbursts and irritability), tantrums, and difficulty holding or switching attention.
- Day-to-day living - the child may find it difficult to keep up daily practices or adjust to changing environments. This can include problems maintaining hygiene, dressing for weather or situations, playing with other children, and interacting with adults, and recognizing distinctions (e.g. teachers, bus drivers, shop workers, etc.)
*The term fetal alcohol effects (FAE) was commonly used for many years to describe both ARND and ARBD symptoms and is still occasionally used as a base description of both conditions. In 1996, the Institute of Medicine (IOM) officially replaced FAE as the preferred terminology so ARND and ARBD could be treated and diagnosed more accurately.
Areas evaluated for FASDs and how they are diagnosed
Unlike other medical conditions associated with prenatal defects, there are no medical tests available for FASD conditions. Doctors and other healthcare professionals look for the signs and symptoms of FASD and also rely on self-reported alcohol use from the mother.
The indicators doctors look for to diagnose FASDs include:
- Prenatal alcohol exposure (though confirmed alcohol exposure is not essential for a diagnosis)
- Poor or stunted growth or development (e.g., problems with attention, low birth weight, small head size, lack of coordination)
- Lower-than-average height, weight, or BMI
- Abnormal facial features (e.g., smooth ridge between nose and upper lip)
Treatment for FASDs
There is no cure for FASDs, with the brain and physical defects that are caused by them lasting a lifetime. However, early diagnosis, intervention, and treatment can improve outcomes and lessen the lasting effects of FAS. The best method is to prevent FAS by not consuming any alcohol during pregnancy.
Other early treatment types include medications to help manage some symptoms, parent training and guidance, education and behavioral therapy and alternative approaches such as holistic therapies. As all children are affected by FASDs have different symptoms and needs, no one approach will work for all. Treatment plans will require close monitoring, follow-ups, and amendments throughout a child's development.
Some common protective factors include:
- Early diagnosis (before the child reaches six years old)
- A nurturing and stable homelife during developmental years, especially through school
- Attending additional educational services, such as special education or social services
- The absence of violence in home life
Read here to learn more about the effects of alcohol on health.
Final thoughts on FAS
Consuming any amount of alcohol during pregnancy is risky, and can lead to harmful effects on an unborn child. Frequent, heavy, and continued use of alcohol during pregnancy can lead to lasting defects and developmental problems that continue to impact a child throughout their lives.
Starting each year on Mother’s Day, Alcohol- and Other Drug-Related Birth Defects Awareness Week is a reminder that alcohol and drug use during pregnancy can be harmful to the health of a mother and her child.
FASDs can be prevented by avoiding alcohol use during pregnancy. Those who need help stopping drinking should consult with a doctor, addiction professional, or other licensed clinicians to explore options for treatment.