What are the risks of drinking during pregnancy?
More than three million women in the U.S. are exposing their babies to alcohol during development — because they don’t know they’re pregnant.
In a new report by the US Centers for Disease Control and Prevention (CDC), 3.3 million women were estimated to be putting their fetus at risk by drinking alcohol whilst sexually active and not practicing birth control.
The team analyzed data from the 2011–2013 National Survey of Family Growth and found that 3 in 4 women who want to get pregnant carry on drinking alcohol when they stop using birth control, with rates likely to be higher when pregnancies are unintended.
“About half of all pregnancies in the United States are unplanned, and even if planned, most women won’t know they are pregnant for the first month or so, when they might still be drinking,” says Anne Schuchat, Principal Deputy Director at the CDC.
But what harm does this cause to a developing baby?
Exposure to alcohol in the womb is one of the leading preventable causes of intellectual disability in children along with a range of developmental conditions known as Fetal Alcohol Spectrum Disorders (FASD). During the first three months, alcohol can lead to physical and intellectual disabilities, such as facial abnormalities. Risks to the central nervous system remain throughout the pregnancy.
“Alcohol can permanently harm a developing baby before a woman knows she is pregnant,” says Schuchat. The report advises health practitioners to inform women to stop drinking as soon as they stop taking birth control.
Is drinking a norm?
The sight of a woman sipping a glass of wine during her pregnancy is common in many parts of the world and deemed by many to be socially acceptable.
A CDC report in 2015 found that one in ten pregnant women in the US reported drinking alcohol in the previous 30 days, and 3% reported binging — classed as four or more alcoholic drinks in once session.
Some countries showed more alarming data: in a study published in the British Medical Journal, drinking rates were found to be as high as 80% during pregnancy in Ireland, and between 40% to 80% in the U.K., Australia and New Zealand.
The CDC warn there are no known safe limits of alcohol during pregnancy and highlight the risk of miscarriage, stillbirth, small birth weight, premature labor — and FASDs.
“Alcohol compromises a number of systems that support the baby,” says Philip May, Research Professor at the Gillings School of Public Health at the University of North Carolina, Chapel Hill. “[For example] nutrients like iron won’t reach the fetus for proper development,” he says.
May has been working on FASDs for more than thirty years and recent work by his team revealed surprising new estimates for the number of children affected by these disorders in the U.S..
“We have estimated rates of 2-5% in the general population and it’s probably very similar for many countries in Europe,” he says. Numbers are estimates for school-age children.
The conditions span a spectrum because symptoms can vary dramatically and can develop at different stages of life. Symptoms consist of growth and facial development challenges but more often behavioral and intellectual disabilities including hyperactivity, poor language skills, concentration and poor math skills — most of which are not obvious at birth and difficult to diagnose before childhood.
“It’s much more common than we thought,” says May.
A broad spectrum of disease
Five levels of disorder fall within the spectrum, starting with the milder Fetal Alcohol Effects and stemming up to Alcohol Related Birth defects, Alcohol Related Neuro Developmental Disorder, Partial Foetal Alcohol Syndrome and then the worst of them all — Fetal Alcohol Syndrome (FAS).
“90% of all outcomes from drinking during pregnancy affect the baby’s central nervous system,” says Denis Viljoen, Chairman of the Foundation for Alcohol Related Research in South Africa. “It’s a disability that remains throughout life.”
A global problem being missed
“[FASDs are] about 1-2% of global birth defects,” says Viljoen.
Populations in Croatia, Australia and Italy have been studied and found to have more cases than expected, as the disorder is easily missed by health professionals.
“Many children with FAS go to school and they’re not doing well but nobody knows why,” says May. In one of his studies, May found that one sixth children with FAS had not been diagnosed by the time his team examined them at age seven. “Approximately 80% go undiagnosed,” says May.
In terms of percentages, one country tops the list by miles. “In South Africa, it is completely out of proportion,” says Vijjoen.
South Africa had the highest numbers globally, with 11.3% of the population estimated to be affected by FASDs in the study. Here, the rates are influenced by socio-economic factors with drinking during pregnancy more common among deprived communities, with poor educational backgrounds and living conditions. “There is a heavy drinking problem in our poorer populations,” says Viljoen.
The biology behind it
Alcohol is rapidly absorbed inside the body, transmitting throughout the organs within half an hour, according to Viljoen. “It’s rapidly absorbed and crosses the placenta,” says Viljoen. Once inside the fetus, alcohol can go on to damage growth and nerve cells during development.
The majority of damage is down to the nerves — namely the brain. “These kids all have mild to moderate mental retardation,” says Viljoen. The impact is greatest among heavy drinkers and the consequences of light drinking are more hotly debated, as experts are yet to decipher an acceptable level of alcohol.
Various factors relating to the mother also come into play, such as their body mass Index (BMI), and nutrition levels.
Is light drinking ok?
A 2013 study by University College London found that light drinking during pregnancy does not harm a child’s intellectual development. One in four mothers in the study reported they were light drinkers during pregnancy, one in 20 said they were moderate drinkers and 2.5% were heavy drinkers. Some children in the group did develop problems, including hyperactivity and social challenges with peers, but no evidence was found in the children of light drinkers.
Viljoen and May, however, believe women should abstain from alcohol — a view supported by the CDC. They see this spectrum of conditions as entirely preventable.
A common example used by some mothers is that earlier children were exposed and have turned out fine. But experts warn that examples cannot be given of prior children as each individual is different — and severity is known to increase in subsequent children.
“The disorder is always worse in later born kids,” says May.
There’s a lot to think about when taking that sip of alcohol. “We’ll never prevent it completely, but prevention is the secret of the whole thing,” says Viljoen.