Fetal Alcohol Syndrome (FAS) and FASD

What fetal alcohol syndrome is

When a pregnant person drinks, alcohol crosses the placenta and reaches the baby at roughly the same level as in the mother's blood. The baby's liver cannot break it down well, and alcohol interferes with how cells grow and move, especially in the developing brain. Damage can occur at any stage of pregnancy, including before the pregnancy is known. The facial features come from exposure in the first trimester, when the face forms. The brain is vulnerable throughout.

No amount of alcohol is known to be safe during pregnancy. Heavy and binge drinking (4 or more drinks on one occasion) carry the highest risk, but harm is not limited to these patterns. Genetics, nutrition and the mother's age affect why some exposed babies are more affected than others.

FAS vs FASD

Fetal alcohol spectrum disorders (FASD) is the umbrella term. It includes:

Because most people with FASD look typical, the condition is widely underdiagnosed and often mistaken for ADHD or behavior problems alone.

Fetal alcohol syndrome facial features

The three key features doctors measure are:

• Smooth philtrum: the vertical groove between the nose and upper lip is flat or absent.
• Thin upper lip: the red border of the lip (vermilion) is narrow.
• Small eye openings: short palpebral fissures, so the eyes look small or wide-set.

Other features can include epicanthal folds, a flat midface, a short upturned nose, low nasal bridge and minor ear differences. These features can soften with age, which makes diagnosis harder in teenagers and adults.

Symptoms and signs by age

Babies

• Low birth weight and small head size (microcephaly)
• Feeding and sleep difficulties, irritability
• Slow weight gain

Children

• Delayed speech, language and motor development
• Learning difficulties, especially with math, memory and abstract thinking
• Hyperactivity and short attention span. Many meet criteria for ADHD
• Poor coordination and balance
• Difficulty linking actions with consequences, following multi-step instructions, and adapting to change
• Vision or hearing problems, and sometimes heart, kidney or bone defects
• Seizures in some children

Teenagers and adults

• Problems with judgment, planning, money management and independent living
• Impulsivity, being easily led, and trouble keeping jobs
• Higher rates of depression, anxiety, school disruption, substance use and contact with the justice system
• Intelligence can range from intellectual disability to the normal range. Day-to-day function is often lower than IQ suggests

How FAS is diagnosed

There is no single test. A pediatrician, developmental pediatrician or specialist FASD team looks at:

1. Prenatal alcohol exposure: confirmed when possible, although FAS can be diagnosed without confirmation when all features are present.
2. Facial features: precise measurements of the eye openings and comparison of the lip and philtrum with standard guides.
3. Growth: height and weight at or below the 10th percentile.
4. Brain: small head size, structural differences on imaging, seizures, or deficits on neuropsychological testing.

Doctors also rule out genetic syndromes that look similar, sometimes with genetic testing. Early diagnosis matters: children diagnosed before age 6 do better.

Treatment and support

FAS is permanent, but a lot can be done:

• Early intervention: speech, physical and occupational therapy from infancy.
• School support: an IEP or 504 plan, small classes, routines, visual aids, concrete instructions and repetition.
• Medicines: for specific problems such as ADHD symptoms, sleep problems, anxiety, depression or seizures.
• Behavior and parent training: approaches that focus on adapting the environment rather than punishment.
• Medical care: checks of hearing, vision, heart and kidneys, and growth monitoring.
• A stable, nurturing home: one of the strongest protective factors against later problems.
• Adult support: help with housing, money and work, often for life.

Preventing fetal alcohol syndrome

FAS is 100% preventable. The CDC, ACOG and the AAP advise no alcohol during pregnancy or while trying to get pregnant. If you drank before you knew you were pregnant, stop now and tell your prenatal care provider: stopping at any point helps the baby. If you find it hard to stop, ask for help. Treatment for alcohol use disorder during pregnancy is safe and confidential, and the SAMHSA National Helpline (1-800-662-4357) is free.

Frequently asked questions

What are the 3 main features of fetal alcohol syndrome?

FAS is diagnosed when a child has three characteristic facial features (smooth philtrum, thin upper lip and small eye openings), growth below the 10th percentile, and evidence of brain involvement, such as a small head, seizures or significant learning and behavior problems.

How much alcohol causes fetal alcohol syndrome?

No safe amount has been identified. Full FAS is most often linked with heavy or binge drinking, but milder forms of FASD can occur with lower levels. Because the effects vary between pregnancies, the only certain way to prevent FASD is to avoid alcohol entirely during pregnancy.

Can fetal alcohol syndrome be cured?

No. The brain damage is permanent. But early diagnosis, therapies, school support, medicines for specific symptoms and a stable home can greatly improve learning, behavior and independence. Many people with FASD lead fulfilling lives with the right support.

What does fetal alcohol syndrome look like in adults?

Adults may have subtle facial features, short stature, and lasting difficulties with memory, planning, judgment and handling money. Many struggle with work, independent living and mental health. Because the face changes with age, adults are often undiagnosed. A specialist assessment can still give a diagnosis and open access to support.

Is fetal alcohol syndrome the same as ADHD?

No, but they overlap. Many children with FASD have attention and hyperactivity problems and meet ADHD criteria. FASD also causes broader difficulties with memory, reasoning and linking actions to consequences. ADHD medicines can help some children with FASD, though responses vary.