What Are the Risks of Drinking While Pregnant?

You may have heard that drinking wine or any other alcohol during pregnancy can have bad consequences for the health of your baby.

This advice is in line with what health experts recommend; according to the Centers for Disease Control and Prevention (CDC), American Academy of Pediatrics (AAP), and the American College of Obstetricians and Gynecologists (ACOG), there is no safe amount of alcohol consumption at any time in pregnancy.

However, there are still quite a few unknowns regarding the use of alcohol in early pregnancy, including in the days before you knew you were pregnant.

Based on the current medical evidence, there is no way to know where to draw the line between safe and unsafe alcohol use in pregnancy. The best choice is to avoid wine, beer, liquor, and all other types of alcohol when you're pregnant.

However, drinking in pregnancy is a decision that every person has to make for themselves, so it's a good idea to educate yourself about the potential risks and effects of drinking while pregnant.

Alcohol During Pregnancy

When a soon-to-be parent consumes alcohol during pregnancy, the alcohol passes from the parent's blood to the fetus through the umbilical cord. Once the alcohol is in the fetus's bloodstream, it affects every part of the body, including the organs and central nervous system.

This is dangerous for two reasons. First, the fetus's brain and other organs are developing rapidly, and they can be negatively impacted by alcohol at any time during pregnancy. Second, babies do not have the ability to metabolize alcohol at the same rate that adults do, which magnifies any detrimental effects on their development.

Alcohol use in pregnancy increases the risk of miscarriage. It also places your baby at risk of a multitude of health problems, including:

• Fetal alcohol spectrum disorders (FASDs)
• Hyperactivity
• Low IQ
• Stillbirth

Is Light Drinking Safe?

Although the frequency and duration of drinking may have more bearing than individual episodes on the detrimental effects of alcohol in pregnancy, no amount of alcohol is considered safe when you're pregnant.

Binge drinking (defined by the CDC as having more than four drinks within two hours) increases the blood alcohol concentration (BAC) far beyond what would be seen in a casual drinker.

This exposes the developing fetus to the same levels of alcohol that cause hangover in adults—at a stage where the brain is still growing and has less capacity for self-repair.

A 2014 meta-analysis (a large review of a group of smaller studies) examined how alcohol consumption in pregnancy affected the health outcomes of 11,900 children.

The researchers found that binge drinking at any time during pregnancy was associated with cognitive problems in infants and children. Moderate alcohol exposure, defined as up to six drinks per week, had a negative effect on children's behavior.

The authors concluded that "the results of this review highlight the importance of abstaining from binge drinking during pregnancy and provide evidence that there is no known safe amount of alcohol to consume while pregnant.

Research on Alcohol During Pregnancy

Studies over the past decade have yielded conflicting results about the risks of alcohol use on infants. For instance, a 2013 study compared birth outcomes in over 5,600 women in England, Ireland, Australia, and New Zealand who were pregnant for the first time.

In terms of alcohol consumption, the authors found that during the first trimester:

• More than half of women reported drinking alcohol.
• 34% reported at least one binge episode.
• 19% said that they had one to two drinks per week. A drink was defined as one glass of wine or less than a 12-ounce bottle of beer.
• 25% said that they drank three to seven drinks per week.
• 15% reported having eight to 14 drinks per week.
• 5% consumed more than 14 drinks per week.

In comparing all of the study participants—both those who drank and those who did not—the data showed no association between alcohol consumption before 15 weeks and adverse birth outcomes, measured as low birth weight, small birth size, preterm birth, and preeclampsia (a potentially life-threatening condition in which a pregnant person develops high blood pressure.

This study did not focus on mental impairment caused by alcohol exposure during pregnancy.

More recent research has found different results, including a 2020 review of 23 studies that examined the effects of alcohol intake in pregnancy. Data from these studies revealed an increased incidence of low birth weight and cognitive problems in children born to parents who consumed alcohol in pregnancy.

Recommendations

The bottom line is that we don't know with certainty where the boundary lies between acceptable and non-acceptable alcohol use during pregnancy. Some studies have shown no effects of alcohol on birth outcomes, whereas other, more recent studies have shown that drinking can cause birth defects and other health issues.

We do know that drinking while pregnant does not confer any benefits on your baby, and it may cause them serious harm. The AAP points out that prenatal exposure to alcohol is "the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities."

The decision about whether or not to consume alcohol while pregnant is a personal one, and something you should discuss with your doctor now that you know the risks and possible effects.

A Word From Verywell

If you know that you drank alcohol around the time you conceived, have a history of drinking, or just enjoy the occasional drink, be honest with your doctor or midwife during your prenatal visits.

Don't minimize your alcohol intake or say you're drinking less than you are. This is especially true if you find it hard to stop or cut back. Bending the facts to please your doctor will help no one, including your baby. Honesty allows you to get help if you need it and to make informed decisions based not on fear, but on facts.