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Column originally published Jan 6, 2004
Column last revised/updated on Sep 5, 2018

There Is No Safe Amount Of Alcohol During Pregnancy

Question: I have been married for several years. My husband and I enjoy a glass of wine at meal times, and we also drink fairly regularly with our friends. I am thinking of starting a family. When I talked to my younger sister who is a nurse, she told me that I should stop drinking; otherwise the alcohol can hurt our baby. I don’t drink and drive, but I am just not sure that I should stop drinking completely in order to have a baby. Is my sister just trying to scare me?


I am going to disappoint you here. Your sister is absolutely right. Alcohol can harm your baby, and you should stop drinking before conceiving your first child. I am really glad that you ask this question before you get pregnant. Let me explain to you in more detail here.

Alcohol has been part of many cultures since early civilization. It is served at weddings, births, and many other celebrations around the world. Drinking to excess and alcoholism has been well recognized not only in North America, but around the globe. With the advent of automobiles, drinking and driving has cost the lives of many young people, leading to the birth of organizations like MADD (Mothers Against Drunk Driving). Alcoholism leads to spouse and child abuse, family disruption, as well as premature death from cirrhosis of the liver and other complications.

The effect of alcohol on the foetus was not well recognized until the last few decades. The first case reports of children born with severe medical problems directly linked to alcohol were published in 1968 and 1973. These children have a number of facial features that are very characteristic, including shortened eye-opening (the distance between inner and outer corners of the eyes), droopy eyelids, flattened mid-face, upturned nose, smooth philtrum (the part between the nose and upper lip), as well as a thin upper lip. These features are most obvious when the children are still very young. The doctors called it foetal alcohol syndrome (FAS).

These children have the most severe form of disease. Their mothers have well-documented drinking problem before and during pregnancy. In addition to their facial features, many of them also have other abnormalities, including low birth weight, poor weight gain after birth in spite of adequate nutrition, congenital heart disease, cleft lip or cleft palate, hearing loss, as well as abnormal kidneys and limbs.

The most troubling problem in FAS is development of the brain, or more accurately the lack of development of the brain. Many of these children are born with a small head. As they develop, they are found to have significant delay in their developmental milestones, as well poor co-ordination and fine motor function. When tested, many children have under-development of multiple areas of their brain which at least partially explain some of the deficits that were noticed on examination.

Worst of all, when these children had their intelligence tested, their IQ (Intelligence Quotient, a measure of intelligence compared with the general population) ranged from 16 to 105, with an average of 66. The average IQ of a large population (like all Canadians) is 100. If an individual’s IQ is below 70, he is regarded as mentally retarded. Therefore, the great majority of children with FAS suffer from severe mental retardation as a result of exposure to alcohol during pregnancy.

As expected, children with FAS have all sorts of learning difficulty in school. They have trouble learning language skills, grasping concepts, and understanding mathematics. Most of them also have difficulty paying attention and controlling their impulse, and have been diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). I should caution here that most children with ADHD do not have foetal alcohol syndrome. FAS is just one of the causes of ADHD.

In addition to difficulty learning academic subjects, these children also have great deal of difficulty understanding social interactions. Therefore, they often misbehave because they misunderstood the social context. Their social intelligence is often far worse than their IQ. They have temper tantrums, mood swings, frustration and anger. Their social problems often make it difficult, if not impossible, for them to live and function independently without special assistance and support from the society.

We still do not completely understand how alcohol affects the foetus. Alcohol is readily absorbed from the stomach of women into the blood. Recent research suggested that women have lower levels of the enzyme alcohol dehydrogenase, which breaks down alcohol in the liver. As a result, women may have higher blood level of alcohol than men after drinking the same amount of alcohol. Furthermore, alcohol passes readily through the placenta to the foetus.

Scientific research in mice found that exposure of foetus to alcohol during the first trimester (the beginning 1/3 of pregnancy) is the major cause of congenital abnormalities in children with FAS. This is the period of time when major organs are formed and developed. Alcohol and its by-products are harmful to developing cells. As a result, there is damage and death to the cells that shape the face, leading to the typical facial features of FAS. This also explains other congenital abnormalities found in children with FAS.

As the pregnancy progresses, continual exposure to alcohol reduces the growth and development of most organ systems in the foetus, resulting in stunted growth and low birth weight. Unfortunately, this problem does not end at birth; many children with FAS are unable to catch up in their growth later on in life, even when they are given adequate amount of nutrition. The loss of foetal cells has permanently reduced their body’s potential to grow normally.

Part of the growth failure in children with FAS is due to a lack of essential nutrients from the mother. Women who drink alcohol may consume less of nutritious food, and alcohol can also stimulate the body to eliminate essential nutrients rapidly, therefore depriving the growing foetus of nutrients that are necessary for its growth and development.

The part of the body that suffers the most is probably the brain. Alcohol not only causes death of young brain cells, it also affects the development of synapses which are connections between brain cells, as well as chemicals called neurotransmitters which help brain cells communicate with each other. The end result is a smaller brain, with reduced cognitive ability (lower IQ), poor attention and impulse control (ADHD), and marked delay in motor and social development.

The detrimental effect of alcohol to the developing brain is not limited to binge drinking, where alcohol level is markedly increased for a period of time. Even lower levels of alcohol are harmful to the developing brain. Since the discovery of FAS, many more children have been identified to have suffered from the effects of alcohol while in the mothers’ wombs, without the obvious facial features. Many of these children have ‘alcohol-related neurodevelopmental disorder’ (also called ARND): reduced IQ, delay in motor or social development, as well as learning difficulties. Other children have ‘alcohol-related birth defects’ (ARBD) like the ones I have listed above.

In this day and age, many adults are trying very hard to improve their health and watch what they eat. Some refuse to buy genetically-modified foods in case there are long-term side effects that scientists haven’t discovered as yet. When they decide to have children, they expect them to be perfectly healthy. However, there is one piece of medical information that is very clear: alcohol is harmful to the foetus, and there is no safe level of drinking during pregnancy. Yet, every year, thousands of babies are born with FAS and other alcohol-related conditions.

If you are planning to get pregnant, I would suggest that both of you should review your drinking habit. It is very difficult for you to change while your husband continues to drink. Both of you need to make a conscious decision to stop drinking completely before conception because, as I have mentioned earlier, the greatest damage to the foetus is likely in the first trimester, often before a woman is even aware that she is pregnant. This won’t be an easy task, but if you want a healthy baby with the best potential in life, you have to stop drinking.

In addition to drinking, cigarette smoke, either directly from the mother, or passively from people around her, can be harmful to the foetus also. This discussion is far too broad and beyond the scope of this column. If you are smoking, consider quitting that also, or at least reduce the number of cigarettes that you smoke. If your family members smoke, ask them to go outside and not to smoke in the car.

If you are one that loves to eat fruits and vegetables, I don’t have to say much more. Folic acid is very important for the development of the foetus. There is plenty of folic acid in fruits and vegetables. Eat sensibly, and avoid things that can be harmful to your baby, and most likely you will have a perfectly healthy one.

[Note to Readers: The updated terminology is Foetal Alcohol Spectrum Disorder, or FASD.]