18 Dec Drinking for Two: Alcohol and Pregnancy
How much alcohol is safe during pregnancy? Clinicians are often asked this question, and the important message is that women who don’t drink alcohol during pregnancy will do no harm to their unborn child.
Conversely, frequent high-alcohol intake and ‘binge’ drinking increase the risk of foetal alcohol spectrum disorders (FASD). We know birth defects result from first-trimester alcohol exposure, but that the foetal brain is vulnerable to damage from alcohol throughout pregnancy. The potential consequences of alcohol use during pregnancy can be devastating, impairing the subsequent growth, neurodevelopment, learning and quality of life of the unborn child.
The most recent (2009) guidelines from the National Health and Medical Research Council of Australia state, “for women who are pregnant, or planning a pregnancy, not drinking [alcohol] is the safest option”. This is prudent advice, because risk to the individual pregnancy is impossible to predict.
Maternal (and hence foetal) blood-alcohol levels are influenced by a range of factors including the mother’s age, body composition, genetics and co-existing disease.
Adding to the complexity is a high rate of unplanned pregnancy, estimated at 50 per cent, which suggests inadvertent exposure may be common.
Alcohol Is Toxic to the Developing Brain
Alcohol is a toxin that readily crosses the placenta. When a pregnant woman drinks alcohol it passes directly via the placenta into the foetal blood stream. Alcohol can disrupt development of the brain, internal organs and face.
FASD encompasses a range of disorders with different features that may result from alcohol exposure in the womb, including foetal alcohol syndrome (FAS), neurodevelopmental disorder with alcohol exposure (ND), and a range of alcohol-related birth defects (ARBD).
Children with FASD may have a small or structurally abnormal brain, but even in the absence of structural changes, they may have problems with learning that limit their academic achievement and ultimate capacity for employment and independent living.
Although the IQ range is wide in children with FASD, they often have particular difficulty with memory, executive function (planning and conduct of complex tasks) and numeracy, and require remedial education.
They frequently exhibit difficult behaviours (such as attention-deficit hyperactivity disorder, conduct and oppositional disorders, risk-taking, anxiety and depression) and either solitary or overly friendly personalities.
They may also grow poorly and have birth defects, and hence abnormal function of the heart, kidneys, ears, eyes and other organs.
These problems don’t go away. FASD involves lifelong disorders, and as affected children enter adolescence they are at higher risk than the general population from drug and alcohol dependence, anti-social and inappropriate sexual behaviours, mental-health disorders, trouble with the law, and incarceration.
The real tragedy of FASD is that it is preventable.
Elizabeth Elliott, AM, is professor of paediatrics and child health at the University of Sydney Medical School and consultant paediatrician at the Sydney Children’s Hospitals Network (Westmead).
Words by Dr E. Elliott