PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Fetal alcohol syndrome (FAS) is the more severe end of a continuum of birth defects known as fetal alcohol spectrum disorders (FASDs).
Fetal alcohol effects (FAEs), otherwise known as alcohol-related birth defects (ARBDs), may represent the milder end of the spectrum.
Other terms for conditions which come under the umbrella of FASD are alcohol-related neurodevelopmental disorder (ARND) and partial fetal alcohol syndrome (pFAS). These are caused by maternal use of alcohol during pregnancy.
There are three main components of FAS:
- Typical facial abnormalities.
- Intrauterine growth restriction and failure to catch up.
- Neurodevelopmental abnormalities causing learning disability, cognitive impairment and behavioural problems
Alcohol is the most common teratogen affecting humans. It is rated as the most common non-genetic cause of mental and behavioural problems in children. Exact numbers are difficult to define in this spectrum of disorder and there are no accurate figures for prevalence in the UK. This is due to a number of factors, including the differing definitions and conditions along the spectrum, the poor accuracy in self-reporting of alcohol consumption, lack of standardisation of levels of drinking, reluctance to make or accept the diagnosis, and paucity of reliable data collection. Hospital episode statistics from the Health and Social Care Information Centre (HSCIC) in England showed 272 admissions with a diagnosis of FAS in 2013-14. Studies suggest significant under-reporting in FAS and FASD.
Most figures come from the USA, where it is estimated that FAS occurs in 0.2-1.5 live births per 1,000 and fetal alcohol spectrum conditions occur much more commonly. Some studies estimate that prevalence of FASD may be as high as 2-5% among school-aged children in North America and Western Europe.
There is much difference between communities, depending on habits and tradition. Studies across the world have shown vastly different figures for incidence of FASD as high as 62 per 1,000 children in Italy and 89 per 1,000 in the Western Cape province in South Africa.
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The sole risk factor is maternal consumption of alcohol during pregnancy. Alcohol is a teratogenic substance which crosses the placenta with ease. Development of the fetus can be affected by alcohol at any stage. Different effects may occur depending on the stage of exposure, however.
Not all women who drink heavily during pregnancy have babies with FAS and it is clear that other factors affect the vulnerability of the fetus. These include the stage of pregnancy affected, the pattern of drinking, the health, age, stress levels and nutritional status of the mother and the use of other toxic substances, including tobacco. Genetic makeup and gene polymorphisms also strongly affect fetal vulnerability for FAS, and other genetic abnormalities can be confused with FAS. Features of FAS may be passed on to subsequent generations, due to structural chromosomal changes caused by prenatal alcohol exposure.
There has been enormous debate about the safe level of alcohol in pregnancy; there have also been many studies to try to ascertain the effects of different levels and patterns of drinking. National Institute for Health and Care Excellence (NICE) guidelines on antenatal care detail some of these and attempt recommendations on the basis of them. In the UK, NICE guidelines, the British Medical Association (BMA) guidance and the Royal College of Obstetricians and Gynaecologists (RCOG) state that women should be advised to abstain if possible in view of the uncertainty (and in particular in the first three months) due to the increased risk of miscarriage. If women choose to drink alcohol, they are advised to have no more than 1-2 units of alcohol no more than 1-2 times a week, as there is no evidence of harm at this level. They are also advised that binge drinking may harm the baby. However, Department of Health (DH) guidelines released for consultation in January 2016 look set to advise that the safest course is for women to abstain from alcohol altogether during pregnancy.
The fact of alcohol abuse may not be known to others. Alcoholism, diagnosis and treatment in primary care can be very difficult and self-reported levels of consumption must be treated with circumspection.
Diagnosis of FAS and FASD is difficult. There is no test, so diagnosis depends on a history or suspicion of in-utero alcohol exposure and on the presence of typical clinical features. Criteria for diagnosis vary and are better defined for FAS than other conditions within the spectrum, so it is not surprising that prevalence figures are a challenge to establish.
Failure of growth
Weight, length and head circumference are all reduced and, whilst the infant who has suffered from placental insufficiency tends to emerge ravenous and eagerly feeds to restore weight, the child with FAS remains stunted for life. Adequate nutrition and a caring environment are not enough to reverse the damage.
These may include any permutation of the following:
- Microcephaly (small head).
- Flat philtrum (flattening of the groove under the nose).
- Thin upper lip.
- Retrognathia in infancy, micrognathia or relative prognathism in adolescence and a low nasal bridge.
- Microphthalmia, strabismus, ptosis and short palpebral fissures.
- Cleft lip and/or palate.
- Posterior rotation of the ears.
These may include:
- Low IQ - but can be normal or even higher than average.
- Attention deficits.
- Memory problems.
- Problems with perceiving consequences, and inability to learn from experience. Poor judgement.
- Poor problem-solving skills.
- Immature behaviour. Poor social skills and lack of control of impulsive behaviour.
- Poor co-ordination.
- Speech and language delay.
- Difficulty with concepts such as maths, money and time.
- Sucking and feeding problems in the neonate. Occasionally, features of delirium tremens due to alcohol withdrawal.
These first three categories of abnormality are the classic triad of FAS but alcohol may have had further effects on the developing fetus, including:
These range from contractures of the finger joints to more severe lesions, such as developmental dysplasia of the hip and abnormalities of the thoracic cage.
These include cryptorchidism and hypoplastic labia as well as other abnormalities of the kidneys and urinary tract.
Hearing and visual impairments
There may be partial deafness and significant visual disability.
Some of these features for FASD can be measured and ranked by criteria such as the 4-Digit diagnostic code; however, there are several different systems with differing criteria. Moreover, some of these guidelines cover FAS, whereas others address the full FASD continuum. Health professionals in the UK currently agree that the Canadian guidelines offer the best diagnostic tool and these are summarised in published BMA guidance.
Other conditions within the fetal alcohol spectrum disorder definition
The scale of the problem of the FASD as a whole is difficult to determine, as it may not be recognised as such without the classic criteria for FAS (ie growth restriction, typical facial anomalies, neurodevelopmental abnormalities). The milder cases may be less likely to be diagnosed. The conditions under this umbrella describe any of the disabilities which may be caused by maternal drinking in pregnancy and which may occur in isolation or as more than one.
Conditions on the lower end of the spectrum compared to FAS include pFAS, FAE or ARBDs, and ARND. Clinical features of these conditions are less well defined.
As children with FAS mature into adolescence and adulthood the craniofacial deformities become less noticeable but the short stature and microcephaly remain.
There may be more likelihood of other stresses and major life events in a childhood of a baby born to a mother who drinks heavily, which may further affect them. Educational achievement may be extremely limited. Children with FAS are more likely to have been in trouble in school and have poor relationships and, as they grow up, be more likely to be in trouble with the law, have inappropriate sexual relationships, mental health issues, addictive behaviours and difficulty living independently. Impulsivity, poor judgement and lack of comprehension cause adults born with FAS to experience major psychosocial and adjustment problems for the rest of their lives.
Factors improving outcome include early recognition and diagnosis, support, a stable home life and absence of violence. Early recognition and diagnosis improve the chance of obtaining a Statement, which will lead to extra support throughout the education process.
Both FAS and FAEs are entirely preventable. Estimates of alcohol consumption in the general population and pregnant women are difficult as there is known to be significant under-estimation and under-reporting. In general, alcohol consumption by women in the UK has fallen slightly over past years, with average weekly unit intake dropping from 9.4 in 2005 to 7.6 in 2010. However, instances of heavy or binge drinking remain high and particularly so in younger women aged 16-24. One study from Leeds of pregnant women aged 18-45 showed that more than 79% drank alcohol in the first trimester of pregnancy, 63% in the second and 49% in the third, with significant numbers drinking over two units per day. However, HSCIC statistics from 2013 show that in Great Britain fewer than one in ten pregnant women had drunk alcohol in the week prior to the survey, as compared to more than five in ten non-pregnant women. The Infant Feeding Survey in 2010 in the UK showed that 40% of women had had alcohol at some point in their pregnancy but only 3% drank more than an average of two units per week. In this survey, 49% said they had given up alcohol altogether due to pregnancy; 46% said they had reduced their intake.
According to the general lifestyle survey in Great Britain in 2011, 31% of women age 16-24 and 34% of women aged 25-44 exceeded three units on at least one day in the week preceding the survey. Alcohol consumption is associated with risk taking and unplanned pregnancy. The UK rate of teenage pregnancy remains higher than other Western European countries. Many pregnancies are unplanned, so much of the alcohol consumed during pregnancy may be at a time when the woman was unaware she was pregnant. Dropping of the advisable safe limits for everyone in recent guidelines may help to address this.
Health promotion must continue to emphasise the need for moderation, if not complete abstinence, perhaps from before conception. Doctors, midwives and nurses giving advice about family planning must emphasise the dangers of alcohol in pregnancy. The social and economic costs are enormous. The dangers of alcohol in pregnancy should be as well known as the dangers of smoking.
Alcohol has been used and abused since antiquity but FAS was unrecognised until it was first described in France in 1968 and again in the USA in 1973. That is not to suggest that problems were previously unnoticed. During the 'gin epidemic' a report from the Royal College of Physicians in 1725 noted that 'weak, feeble and distempered children' were the result. In 1834 a parliamentary report 'Effects of Drunkenness on the Nation' remarked that children tend to be 'born starved, shrivelled and imperfect in form'.
Further reading & references
- Leaflets and Resources; National Organisation for Foetal Alcohol Syndrome - UK (NOFAS-UK)
- Alcohol and pregnancy. Preventing and managing fetal alcohol spectrum disorders; British Medical Association (BMA), June 2007 (updated February 2016)
- Health and Social Care Information Centre (HSCIC) website
- Fetal Alcohol Spectrum Disorders; Centers for Disease Control and Prevention
- Blackburn C et al; Facing the challenge and shaping the future for primary and secondary aged students with Foetal Alcohol Spectrum Disorders (FAS-eDProject) Literature Review, National Organisation for Foetal Alcohol Syndrome - UK, September 2009
- GP Toolkit; National Organisation for Foetal Alcohol Syndrome - UK (NOFAS-UK)
- Mason S, Zhou FC; Editorial: Genetics and epigenetics of fetal alcohol spectrum disorders. Front Genet. 2015 Apr 16;6:146. doi: 10.3389/fgene.2015.00146. eCollection 2015.
- Mead EA, Sarkar DK; Fetal alcohol spectrum disorders and their transmission through genetic and epigenetic mechanisms. Front Genet. 2014 Jun 2;5:154. doi: 10.3389/fgene.2014.00154. eCollection 2014.
- Antenatal care for uncomplicated pregnancies; NICE Clinical Guideline (March 2008)
- Alcohol Guidelines Review – Report from the Guidelines development group to the UK Chief Medical Officers; Department of Health, January 2016
- Burd L, Deal E, Rios R, et al; Congenital heart defects and fetal alcohol spectrum disorders. Congenit Heart Dis. 2007 Jul-Aug;2(4):250-5. doi: 10.1111/j.1747-0803.2007.00105.x.
- Farag M; Diagnostic issues affecting the epidemiology of fetal alcohol spectrum disorders. J Popul Ther Clin Pharmacol. 2014;21(1):e153-8.
- Nykjaer C, Alwan NA, Greenwood DC, et al; Maternal alcohol intake prior to and during pregnancy and risk of adverse birth outcomes: evidence from a British cohort. J Epidemiol Community Health. 2014 Jun;68(6):542-9. doi: 10.1136/jech-2013-202934. Epub 2014 Mar 10.
- Statistics on alcohol. England 2015; The Health and Social Care Information Centre (HSCIC), June 2015
- F McAndrew et al; Infant Feeding Survey 2010, Health and Social Care Information Centre, November 2012
- Drinking (general lifestyle survey overview - a report on the 2011 General Lifestyle Survey); Office for National Statistics
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy
Dr Mary Harding
Dr Shalini Patni