Not all experts agree on the exact amounts and types of alcohol that are considered safe in pregnancy. Evidences regarding safe levels of maternal alcohol consumption are scarce and have mixed conclusions.
Any amount of alcohol intake during pregnancy leads to intrauterine fetal exposure and can cause a wide range of deficits known as Fetal alcohol spectrum disorders. For this reason, the global recommendation among medical groups is for pregnant women to avoid any type of alcohol consumption, including beer, wine and spirits. Since there is no established level of safe alcohol intake in pregnancy, complete abstinence is generally advised.
Effects of Alcohol Consumption in Pregnancy
For pregnant women who want to find out more, this article will provide a summary of evidences regarding the consequences of fetal alcohol exposure, consumption of wine, general recommendations for alcohol intake in pregnancy, and how to get help if you want to stop drinking alcohol.
Growth Retardation and Miscarriage
Alcohol from maternal blood passes through the placenta and reaches the fetus through the umbilical cord (CDC, 2020). According to the NHS, the fetal liver is one of the last organs to develop and does not mature until the latter part of pregnancy. Therefore, babies cannot process the alcohol that gets in their system and can affect their development negatively.
During pregnancy, the following adverse outcomes have been linked to alcohol consumption:
- Spontaneous abortion
- Intrauterine growth retardation
- Premature birth
- Low birth weight
In 2011, Patra et al. concluded in their meta-analysis that maternal intake of 1 to 2 units of alcohol per day during pregnancy was associated with an increased risk of delivering infants with low birth weight, preterm birth and small for gestational age (SGA). This risk further increased with higher doses of alcohol intake.
Later in 2012, Chiodo et al. reported a significant correlation between alcohol use during pregnancy and spontaneous abortions. They found that pregnant women who drank alcohol at least one day per week were 2.59 times more likely to have a miscarriage, compared to those who practiced abstinence from alcohol.
Again in 2014, Avalos et al. showed that pregnant women who drank four or more drinks per week had a significantly higher risk of having a miscarriage. This risk is highest when women drank alcohol during the first 10 weeks of pregnancy.
Fetal Alcohol Spectrum Disorders
According to the NHS, drinking alcohol during the first trimester of pregnancy increases the risk of abortion, premature delivery, and low birth weight. Meanwhile, drinking alcohol after the first trimester can lead to problems after the baby is born, including learning and behavioral difficulties.
These statements are similarly expressed by the Centers for Disease Control and Prevention (CDC, 2020) that fetal exposure to alcohol can cause problems at any stage of pregnancy. In the first three months of gestation, alcohol can cause abnormal facial features in the developing baby. On the other hand, growth and central nervous system (CNS) problems, such as low birth weight and behavioral problems, can occur anytime during pregnancy. The fetal brain develops continuously throughout pregnancy, hence exposure to alcohol at any time can be dangerous.
Drinking alcohol while pregnant can lead to a wide range of adverse outcomes for the infant, known as Fetal alcohol spectrum disorders (FASD) (Sokol et al., 2003). FASD is a gamut of congenital anomalies and life-long cognitive, behavioral, emotional and adaptive functioning deficits, which encompasses 4 specific diagnoses (Lange et al., 2017):
- Fetal alcohol syndrome
- Partial fetal alcohol syndrome
- Alcohol-related neurodevelopmental disorder
- Alcohol-related birth defects
Fetal alcohol syndrome (FAS) refers to a set of clinical manifestations including growth and mental retardation, and facial abnormalities (Wattendorf & Muenke, 2005). It was first described in 1973 in children of alcoholic mothers. Though associated with exposure to alcohol, the principal toxin may be acetaldehyde and its accumulation in the body (Jackson, 2020).
FAS is the most serious among the types of FASD, and may cause the following:
- Smaller head and brain size
- Abnormal facial features
- Small eyes
- Short, upturned nose
- Thin upper lip
- Smaller height and weight
- Vision and hearing problems
- Heart defects
- Kidney and bone problems
At present, even less obvious clinical signs have been associated with alcohol consumption, leading to the development of the umbrella term FASD (Jackson, 2020). Children with FASD can have the following characteristics and behaviors (Lange et al., 2017):
- Abnormal facial features – smooth ridge (philtrum) between nose and upper lip
- Small size of head
- Reduced body weight
- Poor body coordination
- Poor focus and attention
- Poor memory
- School difficulties
- Learning disabilities
- Delays in speech and language
- Intellectual disabilities or low IQ
- Poor reasoning and judgment skills
- Problems with sleep and sucking reflex in infants
- Vision or hearing problems
- Ailments in heart, kidney or bones
Lange et al. in 2017 revealed that the prevalence of FASD was about 8 in every 1,000 children, while 1 out of every 13 women who drank alcohol while pregnant eventually had a baby with some manifestation of FASD.
Light vs. Moderate Drinking of Alcohol
There is currently enough evidence of the teratogenic effects of alcohol exposure in utero, with life-long consequences (Corrales-Gutierrez et al., 2019). However, human studies have not been able to specify the pattern, amount and critical period of prenatal alcohol exposure needed for teratogenesis to happen. Only animal models have been able to demonstrate that vulnerability to the teratogenic effects of alcohol happens at all stages of embryonic development (Sulik, 2014).
At present, there are conflicting data and no clear conclusion regarding adverse effects of pregnant women consuming light to moderate amounts of alcohol. Likewise, there is no accepted risk threshold for alcohol intake during pregnancy (Dumas et al., 2018), and no standardized definitions of moderate and heavy alcohol use (Murray et al., 2016).
In 2011, Patra et al. demonstrated that maternal alcohol intake of up to 10 grams (or about 1 drink) per day was not associated with low birth weight and SGA, while intake of up to 18 grams (or about 1 ½ drinks) per day of alcohol had no effect on preterm birth. Similarly, Kesmodel et al. in 2012 showed that minimal amounts of occasional alcohol consumption in pregnancy did not pose any serious threat to the baby.
In contrast, several animal models have shown that even minimal levels of prenatal alcohol exposure may lead to brain dysfunction and behavioral problems (Hamilton et al., 2014). Likewise, Henderson et al. in 2007 concluded that repeated occasions of binge drinking (5 or more drinks per episode) while pregnant can be linked to possible neurodevelopmental problems in their offspring.
Meanwhile, the same study by Patra et al. (2011) found an overall dose-response relationship with successively increasing risk of adverse outcomes with increasing maternal consumption of alcohol. In 2016, Murray et al. demonstrated that moderate alcohol drinking in pregnancy, with a maximum of 6 units of alcohol per week, was associated with increased risk of early-onset persistent conduct problems in children.
Consumption of Wine During Pregnancy
Wine has been associated historically with religious rites, used as medication or medicinal solvent, and drank as food complement (Jackson, 2020). At present, drinking wine is linked to a number of health benefits, including the following:
- Source of antioxidants
- Keeps heart healthy
- Reduces levels of bad cholesterol
- Regulates levels of blood sugar
- Decreases risk of cancer
- Keeps memory sharp
- Helps keep a slim figure
Because of this, many women get confused whether drinking wine during pregnancy is actually beneficial or harmful. Corrales-Gutierrez et al. in 2019 determined that less than 50% of pregnant women understood the life-long consequences of exposing their babies to alcohol in the womb by consuming beer and wine.
In 2015, Crawford-Williams et al. organized a focus group study and found that wine was the most socially acceptable type of alcoholic beverage for pregnant women to drink, compared to spirits and hard liquor. They also recorded these responses regarding perceptions of wine intake in pregnancy:
- “You see and hear lots more people who sort of think that a glass of wine is actually ok because it calms the mother’s mood which is better for the baby.”
- “If you’re at dinner and someone is pregnant and they have a sip of the wine, I don’t think anything of it.”
- “My midwife said that having a glass of red wine was actually better for the baby.”
- “My mum, when we go over there, she still asks if I would like a glass of wine. And I have to remind her that no, I’m pregnant.”
- “I’ve got a sister-in-law who would have 5 or 6 glasses of wine quite often, and she’s about 32 weeks pregnant. But she is a really anxious, stressed-out sort of person…I think it’s better for you to be relaxed than for you to be really tense and anxious.”
However, according to Avalos et al. in 2014, intake of one drink of wine, beer or spirits results in similar alcohol exposures. In a similar manner, CDC (2020) states that all kinds of alcohol drinks are equally harmful, including all wines and beers. Given the dangers previously discussed with fetal exposure to alcohol, unwinding with a glass of wine is never truly safe for women who are pregnant.
What are the Recommendations for Alcohol Consumption in Pregnancy?
Alcohol consumption in pregnancy has now become the most common non-hereditary preventable cause of intellectual impairment (Corrales-Gutierrez et al., 2019). FASD is an alcohol-related developmental disability, which is globally prevalent but highly preventable (Lange et al., 2017). Due to these life-long consequences to children, it has been generally recommended that pregnant women avoid drinking all types of alcohol (Jackson, 2020).
The potential effects of minimal amounts of alcohol on the developing fetus remain unclear. “Light” drinking may mean differently to different people. Hence, more research is needed to come up with an amount of alcohol – if there is any – that is safe for pregnant women to drink.
Nevertheless, FASD can only be prevented if women do not drink any kind of alcohol during pregnancy. There is no known safe level of alcohol consumption during pregnancy. Likewise, there is no safe time to drink alcoholic beverages during pregnancy (CDC, 2020).
There has yet to be a consensus regarding the lowest dose of safe alcohol consumption in pregnancy. Thus, utmost caution is warranted and abstinence from any type of alcohol intake during pregnancy has been recommended (Corrales-Gutierrez et al., 2019).
According to the NHS, the chief medical officers in UK recommend pregnant women to not drink any alcohol at all. During pregnancy, the more you drink, the greater the risk of long-term harm to the baby. The CDC, U.S. Surgeon General, American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics all recommend that pregnant women should not drink any alcohol of any type.
In 2005, the U.S. Surgeon General issued an advisory on alcohol use in pregnancy. It provided the following statements based on current evidences:
- “Alcohol consumed during pregnancy increases the risk of alcohol related birth defects, including growth deficiencies, facial abnormalities, central nervous system impairment, behavioral disorders, and impaired intellectual development.”
- “No amount of alcohol consumption can be considered safe during pregnancy.”
- “Alcohol can damage a fetus at any stage of pregnancy. Damage can occur in the earliest weeks of pregnancy, even before a woman knows that she is pregnant.”
- “The cognitive deficits and behavioral problems resulting from prenatal alcohol exposure are lifelong.”
- “Alcohol-related birth defects are completely preventable.”
How to Get Help
It is not safe to drink wine, or any other types of alcohol, when you are pregnant. If you accidentally drank wine or beer not knowing that you are pregnant, refrain from drinking further any alcohol for the rest of your pregnancy. If you need help quitting drinking, get help from available authorities.
Any woman who is drinking alcohol during pregnancy can benefit from discontinuing alcohol intake. The sooner a pregnant woman stops drinking, the better for both herself and her baby. Pregnant women can get help to stop drinking alcohol. They can contact their health care providers or their local alcohol treatment centers (CDC, 2020).
Pregnant women who are concerned about their alcohol drinking habits should talk to their doctor. Alcohol support and counselling services are also available, including Drinkline, We are with you, and Alcoholics anonymous.
It is important for pregnant women to unwind once in a while, but drinking wine is not an option during this time. Drinking alcohol of any kind throughout pregnancy can be very dangerous for developing babies. Expert recommendations remain the same across societies and organizations worldwide that no amount of alcohol is considered safe in pregnancy.
Wines, beer, spirits, and even some “non-alcoholic” beverages contain alcohol. Fetal alcohol exposure can only happen when a pregnant mother drinks alcohol. No matter how big or small the risk may be, only by abstinence during pregnancy can mothers avoid entirely the risk of their babies developing FASD.
The ultimate decision lies on every pregnant woman. Throughout the life of your child, there are other sacrifices that you may have to make as a mother. Abstaining from alcohol drinking and exercising due caution during pregnancy is a simple measure to ensure the health of your precious baby.
- Avalos, L. A., Roberts, S., Kaskutas, L. A., Block, G., & Li, D. (2014). Volume and type of alcohol during early pregnancy and the risk of miscarriage. Substance Use & Misuse 49(11), 1437-1445. doi: 10.3109/10826084.2014.912228
- Centers for Disease Control and Prevention. (2020). Fetal alcohol spectrum disorders (FASDs). https://www.cdc.gov/ncbddd/fasd/alcohol-use.html#:~:text=There%20is%20no%20known%20safe,including%20all%20wines%20and%20beer.
- Chiodo, L., Bailey, B., Sokol, R., Janisse, J., Delaney-Black, V., & Hannigan, J. (2012). Recognized spontaneous abortion in mid-pregnancy and patterns of pregnancy alcohol use. Alcohol 46(3), 261-267. doi: 10.1016/j.alcohol.2011.11.006
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- Crawford-Williams, F., Steen, M., Esterman, A., Fielder, A., & Mikocka-Walus, A. (2015). “My midwife said that having a glass of red wine was actually better for the baby”: A focus group study of women and their partner’s knowledge and experiences relating to alcohol consumption in pregnancy. BMC Pregnancy and Childbirth 15, 79. https://doi.org/10.1186/s12884-015-0506-3
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