Intergovernmental committee on Drugs working party on Fetal Alcohol Spectrum Disorders
Fetal Alcohol Spectrum Disorders in Australia: An Update
4.1 Fetal Alcohol Spectrum Disorders
In 2004 the term Fetal Alcohol Spectrum Disorders (FASD) was introduced as an umbrella term to describe the range of effects that can occur in an individual whose mother drank alcohol during pregnancy(Gerberding et al. 2004). There are a number of diagnostic terms used to describe the range of fetal effects stemming from prenatal alcohol exposure including Fetal Alcohol Syndrome (FAS), partial FAS, Fetal Alcohol Effects (FAE), Alcohol Related Birth Defects (ARBD), and Alcohol Related Neurodevelopmental Disorders (ARND).
4.1.1 Fetal Alcohol SyndromeDiagnosis of FAS relies on a triad of features: characteristic facial abnormalities; impaired growth prenatally and/or postnatally; and structural and/or functional abnormalities of the central nervous system (Table 4.1) (Stratton et al. 1996). The lack of an objective diagnostic test may lead to subjectivity in the diagnostic process, which increases the risk of diagnostic misclassification (Abel 1995). Although a number of syndromes have some features in common with FAS, most other birth defect syndromes do not have abnormalities in each of the three categories required for a diagnosis of FAS (Chudley 2008). If the diagnosis of FAS is in doubt, referral to a dysmorphologist or clinical geneticist is recommended both to confirm the diagnosis and exclude alternative diagnoses. Confirmation of the diagnosis requires a history of maternal alcohol use during pregnancy. However, when reliable information on maternal drinking behaviour is unavailable, a diagnosis of FAS can be recorded, providing that abnormalities in the child are consistent with the syndrome and other possible diagnoses have been excluded (Stratton et al. 1996). In 1996 the Institute of Medicine (IOM) published the first diagnostic criteria for FAS, pFAS, ARBD, and ARND. Table 4.1 outlines the Institute of Medicine (IOM) diagnostic criteria for FAS.
Table 4.1: Institute of Medicine diagnostic criteria for Fetal Alcohol Syndrome (Stratton et al. 1996)For accessibility requirements this table is displayed in HTML. For the table version, please view the PDF.
- Prenatal growth deficiency – decreased birth weight for gestational age
- Postnatal growth deficiency – lack of catch-up growth in spite of adequate nutrition
- Low weight to height ratio
- Short palpebral fissures
- Thin upper lip
- Flattened philtrum (an absent or elongated groove between the upper lip and nose)
- Maxillary hypoplasia, epicanthal folds and ptosis may also occur
- Decreased cranial size at birth
- Structural brain abnormalities including microcephaly
- Abnormal neurologic hard or soft signs such as impaired fine and gross motor skills
4.1.2 Other Fetal Alcohol Spectrum DisordersComplete agreement on diagnosis of the diagnostic categories of FASD has not been reached and a number of diagnostic guidelines have been published in the past decade (Astley 2004; Bertrand et al. 2004; Chudley et al. 2005; Hoyme et al. 2005; Astley 2006). Although each of these guidelines has subtle differences in their diagnostic criteria, they all recognise the need to assess characteristics of growth, facial features, neurological structure and function and alcohol exposure in pregnancy (Western Australian Department of Health 2010).
The Institute of Medicine (IOM) guidelines created three categories to describe the outcomes in children who have some effects related to alcohol exposure in utero, but do not fulfil the criteria for Fetal Alcohol Syndrome (Stratton et al. 1996). The three categories, partial FAS (pFAS), Alcohol Related Neurodevelopmental Disorder (ARND), and Alcohol Related Birth Defects (ARBD) require confirmed maternal alcohol exposure.
A diagnosis of pFAS requires some of the characteristic facial features and at least one of the other FAS features: growth retardation; central nervous system neurodevelopmental abnormalities; or a complex pattern of behavioural and/or cognitive abnormalities which cannot be accounted for by familial background or environment alone.
ARND is characterised by central nervous system (CNS) abnormalities (e.g. decreased head size at birth or structural brain abnormalities) and/or neurological functional abnormalities which cannot be explained by familial background or environment alone (e.g. behavioural and cognitive dysfunction such as learning difficulties or poor impulse control and judgement).
Alcohol related birth defects (ARBD) are characterised by physical anomalies such as cardiac, skeletal or renal anomalies or sensory impairment. These include sensorineural hearing loss and eye anomalies which are known from animal models and/or humans to be associated with alcohol exposure (Stratton et al. 1996). The features of each are shown in Table 4.2.
Table 4.2. Fetal Alcohol Spectrum Disorders (Stratton et al. 1996)
|Facial Anomalies||Growth Retardation||CNS Anomalies||Birth Defects|
|FAS with confirmed alcohol exposure||Tick||Tick||Tick||Tick|
|FAS without confirmed alcohol exposure||Unknown||Tick||Tick||Tick|
|Partial FAS||Tick||Some facial anomalies present||Need at least one of these categories (Growth Retardation/ CNS Anomalies)||Need at least one of these categories (Growth Retardation/ CNS Anomalies)|
|Alcohol-related neurodevelopmental disorder (ARND)||Tick||-||-||Tick|
|Alcohol-related birth defects (ARBD)||Tick||-||-||-||Tick|
Fetal Alcohol Effects (FAE) was a term used to describe children who had some but not all the features of Fetal Alcohol Syndrome. The criteria for FAE have not been delineated and the use of this term is not recommended (Sokol and Clarren 1989; Aase et al. 1995; Stratton et al. 1996)
Other diagnostic systems, such as the 4-Digit Diagnostic Code, use different terminology and criteria to describe children who do not have sufficient features to fulfil the diagnosis of FAS (Astley 2004). The 4-digit code enables objective description of the severity and mix of abnormalities seen in children with FASD (Table 4.3). The 4-Digit Diagnostic Code was developed at the University of Washington and a specialist diagnostic service was established (Astley 2010). Eleven percent of the first 1400 patients at the specialist clinic with confirmed
prenatal alcohol exposure (newborn to adult) were diagnosed with FAS/pFAS, 28 percent with static encephalopathy, 52 percent with neurobehavioral disorder, and 9 percent with no evidence of CNS abnormality (Astley 2010). FASD outcomes varied significantly by age, race, gender, alcohol exposure, and presence of other risk factors. These results suggest the range of diagnosis that may be seen within a clinical group. Demand for the diagnostic service was reportedly high (Astley 2010).
It is important to note that diagnosis is particularly problematic for disorders in the FASD spectrum in which characteristic facial abnormalities are not seen, as none of the other characteristic problems (such as growth restriction, CNS abnormalities) are unique to FASD and are often associated with factors such as low SES and poor maternal nutrition (O'Leary 2004). Studies estimating prevalence should therefore control carefully for confounders.
Table 4.3 Example of use of the 4-digit diagnostic code (Astley 2004)
In Australia, a challenge for health professionals is agreement on a model for diagnosing FASD. It is suggested that the diagnostic method must be evidence based, sensitive and specific, and account for other exposures during pregnancy and early life events. Training in the diagnostic method needs to be readily available in both metropolitan and regional Australia. A uniform diagnostic capacity, agreed and applicable across Australia, would assist in identifying opportunities for intervention, prevention and treatment for FASD. This is discussed in more detail in Chapter 9.
4.1.3 Neurocognitive differences between FAS and other FASDClinic based studies involving neuropsychological testing show that performance of children with ARND is similar to children with FAS and different from normal controls (Mattson and Riley 1998). Recently, Chasnoff and colleagues examined the neurodevelopment profiles of children with FAS, pFAS, or ARND and found that children who met tightly defined physical criteria for a diagnosis of FAS demonstrated significantly poorer neurodevelopmental functioning than children with pFAS and ARND. Children with pFAS and ARND were similar in all neurodevelopmental domains that were tested (Chasnoff et al. 2010).
4.1.4 Effects of alcohol on pregnancy outcomes and the health of the neonatePrenatal alcohol exposure also increases the risk of a number of adverse pregnancy outcomes that are not classified as FASD. Children born to mothers with alcohol-related problems are at increased risk of pre-term delivery, perinatal death, having an Apgar at five minutes of less than seven, being transferred to special care nursery and having a significantly longer hospital stay than infants born to women without these diagnosis (Olegard et al. 1979; Little et al. 1990; Burns et al. 2006; O’Leary et al. 2009; Astley 2010). The risk of mortality in the offspring is also increased following heavy maternal alcohol consumption including stillbirth (Kesmodel et al. 2002; Aliyu et al. 2008; Strandberg-Larsen et al. 2008; O’Leary et al. 2012) and infant mortality (Kesmodel et al. 2002; Strandberg-Larsen K 2009). Children of mothers with an alcohol-use disorder have a three-fold increased risk of pre/perinatal cerebral palsy, although the fraction of pre/perinatal cases of cerebral palsy attributable to prenatal alcohol exposure is low at 0.25 percent (O’Leary et al. 2012).
4.1.5 Long-term effects of FASD: Secondary disabilitiesMany of the adverse effects from alcohol consumption in pregnancy persist over time and result in significant challenges in adulthood. Prospective longitudinal studies have reported a range of adverse life outcomes including disrupted education and persistent behavioural and mental health problems (Streissguth et al. 2004; Sayal 2007; Spohr et al. 2007; Sayal et al. 2009; O'Leary et al. 2010; Robinson et al. 2010) Individuals with FASD are at increased risk of problems in adulthood classified as ‘secondary disabilities’ (Streissguth and O'Malley 1997; Clark et al. 2004; Streissguth et al. 2004). These secondary disabilities are thought to occur through interaction between environmental risk and protective factors and FASD impairments such as neurodevelopmental and mental health problems (Steinhausen and Spohr 1998; Clark et al. 2004). Adaptive functioning has been identified as a key predictor of the development of secondary disabilities with better outcomes for individuals with high adaptive functioning (Clark et al. 2004). Risk factors for secondary disabilities include disrupted family life and exposure to violence, while living with a foster caregiver is a significant protective factor.
Secondary disabilities include:
- Mental health problems including anxiety and depression (Famy et al. 1998; Streissguth et al. 2004; Barr et al. 2006; Sayal 2007; Hellemans et al. 2010);
- Vulnerability to substance use disorders (Yates et al. 1998; Baer et al. 2003; Alati et al. 2006);
- Vulnerability to manipulation (Streissguth 2007);
- Suicide (O'Malley and Huggins 2005);
- Inappropriate sexual behaviour (Streissguth et al. 2004);
- Educational and employment difficulties (Clark et al. 2004; Spohr et al. 2007);
- Requiring supported living (Clark et al. 2004);
- Parenting problems (Clark et al. 2004); and
- Trouble with the law and incarceration (Streissguth et al. 2004)
percent of adolescents and adults with FAS/FAE reported experiencing disrupted schooling; 53 percent of adolescents had been suspended, 29 percent expelled and 25 percent dropped out of school. Learning, behavioural and social problems were common at school. Trouble with the law was reported for 60 percent of adults, including shoplifting, theft, assault, burglary and domestic violence. Half of adolescents and adults had been confined, 35 percent gaoled; 23 percent admitted for psychiatric problems; and 15 percent admitted for drug and alcohol treatment. Drug and alcohol problems were present in 29 percent of adolescents and 46 percent of adults. A stable, nurturing home environment and early age of diagnosis were protective for the adverse life outcomes. Inappropriate sexual behaviours and substance use problems were more common in participants who had been the victims of abuse or domestic violence. Adults with FAE had similar outcomes to those who had FAS. This study had a large sample size and adjusted for some potential confounders including family environment, giving weight to its findings; however, it used superceded diagnostic criteria.
Spohr et al. have reported findings from a 20-year follow-up of a German cohort of individuals with FAS and FAE (Spohr et al. 2007). Thirty-seven of fifty-two participants (71 percent) took part in the 20-year follow-up and the average age at re-assessment was 23 years. Facial features were much less marked, although long philtrums and thin upper lips were still prominent findings. Microcephaly persisted in 17 (46 percent) and this finding was associated with intellectual disability. Many individuals exhibited catch-up growth; however, 35 percent had a height below the third percentile and 24 percent had a weight below the third percentile. Almost half (49 percent) had received only special education; 38 percent completed primary school and 13 percent had a secondary school education. Thirteen percent had held ordinary jobs, although 69 percent had received some job training. A mismatch between abilities and skill requirements was identified as an obstacle to completing job training. Twenty-seven percent lived in institutions, 35 percent lived in a dependent-living situation with assistance from others, 30 percent lived independently and eight percent lived with a parent. Emotional and behavioural problems reported included attention problems, thought problems and aggressive and intrusive behaviours. These were independent of cognitive ability and did not differ between individuals with FAS and FAE. There was a strong persistence of attention and aggression problems from childhood, while intrusive behaviours and thought problems were emerging issues. The protective factors identified in Streissguth et al. were present in this sample but did not mediate outcomes (Streissguth et al. 2004). Limitations of this study include the use of superseded diagnostic criteria, a small sample size with 29 percent lost to follow-up and lack of adjustment for confounders such as the family environment.
It is difficult in these studies to disentangle potential contributors to adverse life outcomes. For example, disrupted school education is likely to lead to employment difficulties regardless of FASD. However, these studies consistently report difficult life trajectories which are not explained by IQ alone and are not confined to individuals with FAS as they are reported across the spectrum of FASD. The risk of these adverse life outcomes, described as the secondary disabilities or outcomes of alcohol exposure in utero, may be modified by environmental factors such as early diagnosis and by experiencing a stable and nurturing home environment (Streissguth et al. 2004).