1.5 Fetal alcohol syndrome
There are a range of disorders associated with maternal alcohol consumption during pregnancy which are collectively known as fetal alcohol spectrum disorders, FASDs. The best characterised is fetal alcohol syndrome, FAS. FAS is defined by four criteria, the first of which is excessive maternal alcohol intake during pregnancy, the other three being:
central nervous system abnormalities in the fetus/infant.
FAS is considered to be the leading cause of mental retardation in the world and is linked to impaired learning, attention problems, slower reaction times and impaired problem solving, planning and ability to keep track of things (National Institute on Alcohol Abuse and Alcoholism, 2000). Studies from the 1970s and 1980s estimated the incidence rate of FAS in the USA as 1–2 cases per 1000 children born each year. In a population-based study in Seattle in 1997 the rate was nearly 1 per 100 live births. The highest rates to date report 4.6 per cent of 6-year-old children in one community within the Western Cape Province in South Africa (Strömland, 2004).
The mechanisms that result in FAS are complex. Ethanol and acetaldehyde present in the mother's circulation cross the placenta and circulate freely through the blood vessels of the developing fetus. Fetal development involves the division and migration of cells in a carefully orchestrated manner, a process that is disrupted by substances such as ethanol. The developing nervous system is particularly sensitive to disruption.
Not all children who are exposed to alcohol during fetal life are born with FASDs, and there may be several risk factors, involving genetic as well as environmental factors. There are also likely to be many other contributing factors such as nutrition, parental care, drug abuse and smoking which make research into FAS complicated. There are no treatments to reverse the damaging effects of alcohol on the developing brain, although the characteristic facial features lessen during adolescence. A safe threshold of alcohol consumption or critical period during pregnancy when alcohol must be avoided has not been identified. Women who are pregnant, or even those who are just likely to become pregnant, are advised to abstain from drinking alcohol. Whilst FAS is entirely preventable by avoiding alcohol during pregnancy, in reality a significant number of women of childbearing age in all western cultures are dependent on alcohol to a certain extent. Treating alcohol dependence in these women is therefore a health care priority for the protection of any future children, as well as for their own health.