Fetal alcohol spectrum disorder

Fetal Alcohol Spectrum Disorders (FASD)

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Alcohol is a common human teratogen that, when ingested by a pregnant woman, can produce a wide array of fetal complications. The fetus’s developing brain seems most sensitive to prenatal alcohol exposure: Alcohol-related brain damage can be quite diffuse, ranging from microcellular, neurochemical aberrations to macroscopic malformations (Stratton, Howe, and Battaglie, 1996).

What is FASD ?

The term FASD refers to a range or group of conditions that include fetal alcohol syndrome, alcohol-related neurodevelopmental disorder or problems related to the development of the nervous system, and alcohol-related birth defects. Although FASD can cause lifelong serious disabilities, including a combination of physical, behavioral and learning problems, the term FASD itself is not intended for use as a clinical diagnosis.

Definition 

 Fetal alcohol spectrum disorder (FASD) refers to the lifelong effects caused when an unborn baby is exposed to alcohol. When a pregnant woman drinks alcohol, the alcohol in her  blood passes through the placenta into the developing baby. The baby can’t process alcohol as well as the mother can, which means it can limit the growth of brain cells and damage the baby’s central nervous system (or CNS) and other organs.

The following  are the disorders under the FASD category:
• FAS—is a set of mental and physical disorders that can include mental retardation, brain dysfunction, physical abnormalities, learning disabilities, and psychological disorders.  FAS occurs as a result of prenatal exposure to alcohol.
• Partial FAS—This includes some signs and symptoms of full FAS but not all three of the characteristics noted in the previous bullet.
•  Alcohol-related birth defects (ARBD)—This includes just alcohol-related physical abnormalities.
• Alcohol-related neurodevelopmental disorder (ARND)— This includes central nervous system abnormalities, as well  as cognitive and behavioral problems.

Structural Brain Development

Fetal alcohol exposure also can affect the development of brain structure. Advances in imaging techniques are allowing researchers to better understand this effect on the brain’s structure and, consequently, its functioning. 

The imaging techniques researchers use most often are magnetic resonance imaging (MRI) and functional MRI (fMRI). MRI studies of people exposed to alcohol prenatally show differences in the brain’s size and volume, as well as in tissues within the brain compared with people who were not exposed to alcohol. These structural differences in the brain may be related to the problems people with FASD experience on tests of various behaviors and cognitive skills, such as learning and memory.

Another brain-imaging method, fMRI, uses a strong magnetic field to show how blood flows in the brain. In general, more blood flows toward an activated brain structure. Researchers can track this flow of blood to determine what part of the brain responds to particular stimuli and how different parts  of the brain function. 

For example, researchers used fMRI to determine that people with FASD showed different patterns of activity in various areas of their brains than those of people who were not exposed to alcohol.  The brain activation patterns were similar in both children and adults with FASD, showing that the brain changes associated with FASD do not necessarily improve  with age.
These brain changes have been linked with a constellation of effects that range from intellectual and learning disabilities and speech and language delays to behavioral and emotional difficulties, poor social skills, and motor deficits.

Facial Dysmorphology

Prenatal alcohol exposure can cause facial dysmorphology, or particular changes in facial features. Recognizing this specific pattern of facial features is a critical screening tool for diagnosing children with the full FAS. However, not everyone  has access to a specialist who can identify these features, which are required for a diagnosis of FAS. In addition, fetal alcohol exposure affects many children who do not have these distinctive facial features. Because of this, recognizing FASD primarily on the basis of facial features misses many affected children.

What are the signs and symptoms? 

FASDs can affect each person in different ways and may range from mild to severe.  Physical problems may include a small head size, abnormal facial features such as a smooth ridge between the nose and upper lip, dental abnormalities, bone defects, shorter-than-average height, low body weight, and heart, kidney, liver, vision and hearing problems. Behavior and learning problems may include hyperactivity, difficulty in paying attention, poor memory, difficulty in school (especially with math), learning disabilities, speech and language delays, low IQ, and poor reasoning and judgment skills.

Diagnosis

A diagnosis of Fetal Alcohol Syndrome (FAS) is based on certain criteria: facial features, small birth weight, central nervous system dysfunction, and a his tory of prenatal exposure to alcohol.  Babies who do not have all the physiological symptoms may be given a diagnosis of Fetal Alcohol Effects (FAE) or partial Fetal Alcohol Syndrome (pFAS).  Together, FAS, pFAS and FAE are referred to collectively as Fetal Alcohol Spectrum Disorders (FASD). 

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 Facial Features
 Children with FAS may have some or all of the following facial characteristics: 
• Small eye openings
• Smooth, wide philtrum 
• Thin upper lip  

Only babies who were exposed to alcohol during a specific period of pregnancy will have the facial features of FAS.  Any of these facial features can occur in a healthy child as a matter of genetics, features that are inherited from a birth parent.  Only when several of these features are present along with central nervous system symptoms together with prenatal alcohol exposure will FAS be considered for diagnosis.  Only about 10% of children with FASD receive a diagnosis of FAS. 

Physiological Anomalies 

Babies with FAS may have low birth weight, and may have trouble gaining weight.  The head circumference may be smaller than normal.  Some infants may have heart defects or suffer anomalies to the ears, eyes, liver, or joints.   Children may show no physical symptoms at all yet may still have significant damage to the brain and central nervous system.  About 90% of children with FASD have no physical features of the syndrome. 

Developmental Delays 

Many children with FASD have developmental delays.  Less than half of children with full FAS have mental retardation.  90% of children with FAE have IQs in the normal range.  Most children with FASD appear to be bright and outwardly normal. 

Central Nervous System 

Most infants with FAS are irritable, don’t eat well, don’t sleep well, are extra sensitive to sensory stimulation, and have a strong startle reflex. Many are diagnosed with Sensory Integration Disorder (SID) and/or Central Auditory Processing Disorder (CAPG).  They may hyperextend their heads or limbs, and can exhibit hypertonia (too much muscle tone) or hypotonia (too little muscle tone) or both.  Many children with FASD also have Attention Deficit Hyperactive Disorder (ADHD). 

There are also a number of invisible FASD characteristics, which may include:
• attention deficits
• memory deficits
• hyperactivity
• difficulty with abstract concepts (eg maths, time and money)
• poor problem-solving skills
• difficulty learning from consequences
• poor judgement
•  immature behaviour
• poor impulse control
• confused social skills.

Prevention of FASD

Since alcohol use among women of childbearing age is a leading and preventable cause of FASD, the Centers for Disease Control and Prevention (CDC) urges pregnant women not to drink alcohol any time during pregnancy or if they are planning to become pregnant.
Remember, no amount of alcohol consumption can be considered safe during pregnancy and alcohol can damage a fetus at any stage of pregnancy, even before a woman knows that she is pregnant. 

Early intervention for infants and young children with FASD
The damage caused by prenatal alcohol exposure lasts for a lifetime and the health effects cannot be reversed or cured. However, research shows that early intervention and treatment can improve the affected child’s development. The appropriate combination of interventions and support include medication, behavior and education therapy, and parent training.

What can you do if you think your child has FASD?

To help your child reach his or her full potential, it is very important to get help as early as possible. Talk to your child’s health care provider about your concerns. You may ask to see a specialist such as a developmental pediatrician, child psychologist, or clinical geneticist. Special school services can help with learning problems. Contact your local early intervention agency (for children younger than 3 years of age) or local public school (for children 3 years of age or older).

Intervention at School School-based therapies may be able to address a range of issues, from self-awareness, self-regulation and social skills to language, literacy, and mathematics training. Among school- age children, such interventions show promise for improving classroom behavior and even academic achievement. This is especially true for younger children, whose brains are more adaptable. Though they may still lag behind children who are not exposed to alcohol prenatally, children with FASD can benefit from these interventions—both in terms of regulating their behavior and improving their academic performance.

Nutritional Supplements 

Another promising area of research is on nutrition as a therapeutic intervention for offsetting the problems associated with FASD. For example, animal studies show that certain nutrients, such as zinc, folate, and choline, may protect the developing fetus from the harmful effects of alcohol.

One study monitored pregnant animals that were given supplemental choline and that also were exposed to alcohol.  As a result of the choline, the newborns had less severe alcoholrelated birth weight reductions, physical defects, and changes in behavior. Choline and other nutrients also may help improve the symptoms of FASD, even when administered after being exposed to alcohol prenatally and during postnatal development.

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