Foetal Alcohol Syndrome in Adults: How FAS Affects Adulthood

Published On: October 25, 2022

What is Foetal Alcohol Syndrome?

Foetal alcohol syndrome (FAS) is a condition caused by exposure to alcohol in the womb. Exposure to alcohol during pregnancy leads the foetus to experience growth problems and defects that are irreversible.

Alcohol travels through the umbilical cord into the baby, but the amount of alcohol known to cause FAS is unknown. [1] Unborn babies cannot process alcohol well, causing brain damage and physical abnormalities.

It is likely that mothers will lose the baby if they drink in excess, but if the birth is a success, the baby will be left with life-long issues and defects. Even drinking in the first trimester can cause developmental defects, so the more alcohol that is consumed, the greater the chances of developing FAS.

FAS is a type of foetal alcohol spectrum disorder, known as FASD. Alcohol that crosses the placenta causes an increased blood alcohol concentration in the foetus, as babies cannot metabolise alcohol as adults can.

When alcohol crosses through the mother into the unborn foetus, it can kill any healthy cells in the baby, harming the development of further cells. Alcohol also slows the blood flow through the placenta, essentially starving the foetus of both nutrients and oxygen.

Symptoms and Warning Signs of FAS


As always, early diagnoses can prevent secondary problems from developing such as learning difficulties and mental health conditions. The severity of the problems of FAS can depend on the level of alcohol consumed whilst developing in the womb.

As a child, the signs of FAS are visible. Babies born with FAS are usually underweight due to slow growth and have specific facial deformities. Babies usually have smaller eye sockets and flattened cheekbones.

The symptoms of FAS will be a mixture of cognitive difficulties, mental conditions, physical disabilities, and general difficulties coping with day-to-day life. [2]

Brain and Nervous System Problems:

  • Difficulty with balance and poor coordination
  • Intellectual disability
  • Learning disorders
  • Poor memory
  • Delayed development
  • Short attention span
  • Difficulty processing information
  • Poor reasoning and poor judgement of situations
  • Difficulty problem-solving and identifying the negative consequences of choices
  • Hyperactivity (possible attention deficit and hyperactivity disorder – ADHD)
  • Jitteriness
  • Mood swings
  • Mental health disorders

Physical Symptoms:

  • Deformities of the joints, limbs, fingers, and toes
  • Slow physical growth – both before and after birth
  • Vision problems
  • Hearing problems
  • Small head circumference
  • Smaller brain size
  • Heart defects
  • Kidney problems
  • Bone issues

FAS tend to produce distinctive facial features, such as:

  • Small eyes
  • Very thin upper lip
  • A short nose
  • Upturned nose
  • Smooth skin between the nose and upper lip

Behavioural symptoms:

  • Difficulty functioning and coping with social interaction
  • Finding school difficult
  • Trouble getting along with peers
  • Poor social skills
  • Difficulty adapting or changing from one task to another
  • Lack of impulse control
  • Behavioural difficulties
  • No concept of time
  • Difficulty staying on task
  • Find it difficult to plan tasks and work towards goals
  • Aggression
  • Inappropriate social conduct (breaking laws and rules)
  • Alcohol and substance abuse
  • Inappropriate sexual behaviour

FAS in Adults

Woman support

The symptoms and features that are common in those with FAS last into adulthood. That being said, some features may change or diminish over time. Secondary disabilities such as social behavioural issues, trouble with the law, or addiction are very common in adults with FAS. [3]

Steissguth’s research found that following puberty, FAS features become less distinctive. Furthermore, patients tend to have less of a problem with weight, but height issues persisted post-puberty. [4]

A study by Spohr et al focused on 37 individuals with a history of FAS. These 37 individuals either had a history of FAS or FAE (foetal alcohol effects).

The first medical assessment was given at age 5, followed by a 20-year follow-up. The features that appeared at the first assessment had almost diminished by the second assessment, apart from the thin upper lip.

Many patients displayed ‘catch-up’ symptoms with regard to weight, height, and BMI. The only feature that failed to change dramatically was head circumference.

Some people don’t get diagnosed with FAS until adulthood. [5] Diagnoses in adults can prove challenging due to a lack of alcohol exposure history.

It is also difficult to notice what features the patient started out with, and how they have changed. [6] However, the persistent thin upper lip and short stature are features that aid adult diagnosis. Behaviour and cognitive ability are also assessed in adults being evaluated with FAS.

There has been a positive correlation found between alcohol exposure and behavioural issues in adults with FAS. [7] Mental health is of great concern in adults with FAS, having a negative impact on over 90% of patients.

This includes:

  • Difficulties with attention and gets distracted easily
  • Lack of decision-making and planning
  • Internalising problems and emotions
  • Struggling with depression, anxiety and OCD
  • Motor function and executive function

This can make it increasingly difficult to navigate adult life, especially if you are not receiving adequate treatment.

Those with FAS tend to struggle to hold down a job and handle money and employment as a result: [8]

  • Almost 90% of adults with FAS can’t hold down a regular job
  • 70% of adults with FAS are unemployed
  • 80% of adults with FAS require assistance with daily life, and 66% of adults require living assistance
  • 60% of adults with FAS struggle with alcohol addiction or drug dependency

Secondary disabilities (disabilities that develop) are the biggest contributor to mental health issues, anti-social behaviour, and addiction.

The motor function of two groups of adults with FAS were evaluated against those without FAS. The adults with FAS seemed to demonstrate: [9]

  • Poor balance
  • Slow finger movement
  • Slow hand movement
  • Slow foot movement
  • Motor sequencing errors

These individuals experienced difficulty focusing on the tasks set and couldn’t maintain their attention. They also performed poorly on the auditory-attention tasks.

Treatment Available for FAS

sono 1

There is no treatment for FASD conditions, as the damage to both the brain and the body is irreversible. However, early diagnoses with both support and management can make a big difference to the future of those with FAS.

If you think your child or a loved one might have FAS, contact your GP and seek medical help. Once your child or loved one has been diagnosed, they will be able to access medical care and follow this with appropriate behavioural training and educational needs.

There are also support groups available to use as a source of education, advice, and mutual support. The FASD Network UK is an organisation designed to provide information and educational therapy on FASD. This organisation was founded in 2011, aiming to advance strategic development and research. [10] [11]

Training is provided and delivered to:

  • Foster carers
  • Adopters
  • Kinship carers
  • Birth families
  • Social workers
  • Alcohol professionals
  • Teachers
  • Police
  • All professionals

Summary: Adults with FAS

Alcohol consumption during pregnancy can give babies medical conditions and developmental disabilities. These are foetal alcohol effects, which can also cause alcohol abuse and substance abuse later in life.

Alcohol-exposed children have a slower natural development, with reduced healthy brain cells and neurobehavioral effects. The only way to avoid FAS is to avoid alcohol during pregnancy; there is no ‘safe’ level of alcohol to consume whilst pregnant.

There is little known about the full impacts of FAS on adults. However, the social, behavioural and mental effects endure through childhood into adulthood, and we know that some of the facial features are less recognisable after puberty.

Secondary disabilities, mental health problems, and anti-social behaviour perseveres and impacts their ability to live on their own.

Adults with FAS are said to be more prone to certain diseases, such as:

  • Autoimmune disease
  • Diabetes
  • Hypertension
  • Cancer




[3] Moore EM, Riley EP. What Happens When Children with Fetal Alcohol Spectrum Disorders Become Adults? Curr Dev Disord Rep. 2015 Sep;2(3):219-227. doi: 10.1007/s40474-015-0053-7. Epub 2015 Jun 24. PMID: 26543794; PMCID: PMC4629517.

[4] Streissguth AP, Aase JM, Clarren SK, Randels SP, LaDue RA, Smith DF. Fetal alcohol syndrome in adolescents and adults. JAMA. 1991;265(15):1961–1967.

[5] Chudley AE, Kilgour AR, Cranston M, Edwards M. Challenges of diagnosis in fetal alcohol syndrome and fetal alcohol spectrum disorder in the adult. American Journal of Medical Genetics Part C, Seminars in Medical Genetics. 2007;145C(3):261–272.

[6] Temple VK, Ives J, Lindsay A. Diagnosing FASD in adults: the development and operation of an adult FASD clinic in Ontario, Canada. Journal of Population Therapeutics and Clinical Pharmacology = Journal de la therapeutique des populations et de la pharamcologie clinique. 2015;22(1):e96–e105

[7] Day NL, Helsel A, Sonon K, Goldschmidt L. The association between prenatal alcohol exposure and behavior at 22 years of age. Alcoholism: Clinical and Experimental Research. 2013;37(7):1171–1178.


[9]  Connor PD, Sampson PD, Streissguth AP, Bookstein FL, Barr HM. Effects of prenatal alcohol exposure on fine motor coordination and balance: A study of two adult samples. Neuropsychologia. 2006;44(5):744–751.



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