How early in the pregnancy does alcohol affect the baby?

Written by Brandon Okey. Mina Draskovic, B.Psy., reviewed this content for accuracy.

Alcohol begins affecting your baby as early as the third week of pregnancy, when most women don’t yet know they’re pregnant. Early exposure also disrupts normal fetal cellular development, which may alter brain formation, facial features, and organ systems.

Sunderman, et. al. propose that “alcohol use during weeks five through ten from the last menstrual period was associated with increased spontaneous abortion risk…” Each additional week of alcohol consumption raises the risk by 8%, even at low consumption levels and without binge drinking episodes.

If you’re planning a pregnancy and you’re concerned about your drinking habits, you need professional support to protect your baby’s development and help you achieve long-term sobriety. At Ardu, we transform addiction’s challenges into strength through our evidence-based alcohol recovery programs.

What happens if you drink before you know you're pregnant?

Maternal alcohol consumption at the time of conception can impact the unborn baby even before the mother knows she’s pregnant. Conception begins a cascade of cellular development that’s sensitive to environmental influences, including alcohol exposure.

During early pregnancy, alcohol levels in your bloodstream reach the fertilized egg through your reproductive system. This exposure may affect how cells divide in the first moments of development. The genetic material being organized during the first weeks of pregnancy can be disrupted by alcohol’s toxic effects and can alter development.

Researchers proposed that alcohol acts as a teratogen at conception; it crosses the placenta and accumulates in amniotic fluid, where it causes epigenetic (cellular) changes, increases oxidative stress, and disrupts gene expression. These factors affect the foundation of embryonic development before most women know they’re pregnant.

A 2013 study confirms that before implantation, consumption during pregnancy might impact the zygote’s ability to develop properly, leading to alcohol-related birth defects.

Most women discover their pregnancies between 4–6 weeks, well after early cellular development has begun. By the time a pregnancy test shows positive, your baby’s neural structures are already forming. But the impact of alcohol during conception depends on how much you drink and when you stop.

While not every drink guarantees harm, why take the risk? If you’re trying to get pregnant, skip alcohol and give your baby the best possible start.

Does binge drinking in the first 2 weeks affect pregnancy?

Binge drinking involves consuming 4 or more drinks on a single occasion. This amount of alcohol during the earliest days of pregnancy can be risky. When heavy exposure occurs during the first two weeks, it can trigger serious developmental problems. Binge drinking:

Interferes with the embryo’s ability to properly attach to the uterine wall. This may lead to early pregnancy loss.
Can trigger cell death in critical developmental regions that cannot be repaired in later stages.
Disrupts the folate metabolism necessary for proper DNA formation, triggering lasting genetic consequences.
Alters oxygen delivery to embryonic cells during cell divisions.
Impairs the formation of the neural tube, which later develops into the brain and spinal cord.
Changes how stem cells differentiate into specialized tissues.
Compromises early placental development, which affects later pregnancy health and nutrient delivery.
Causes alcohol-induced inflammation that damages delicate forming structures before they’ve fully developed.
Alters the hormone signaling systems that guide embryonic development.
Reduces cellular adhesion that affects how tissues join together correctly during formation.

Binge drinking patterns don’t allow the embryo recovery time between exposures. Unlike moderate drinking, these intense alcohol peaks create a more toxic environment during developmental windows that cannot be reversed. Animal studies show that when the same amount of alcohol is given in condensed time versus spread out, the developing brain suffers more severe damage.

Women planning pregnancy while managing alcohol use deserve specialized care that honors their journey. At Ardu, our women’s alcohol recovery program creates the supportive foundation you need to build the healthy, joyful future your family deserves.

Are 0.5% alcohol beverages safe when pregnant?

Low-alcohol beverages labeled as 0.5% alcohol by volume aren’t risk-free for pregnant women. These drinks do contain far less alcohol than standard alcoholic beverages, but they still deliver some alcohol to your bloodstream. When consumed regularly, these small amounts could potentially contribute to cumulative alcohol exposure. Complete abstinence from alcohol is the safest option during pregnancy.

There is no medically established safe threshold of alcohol consumption during pregnancy, so you should avoid alcoholic beverages during pregnancy, regardless of alcohol content.

Can you drink alcohol during the two-week wait?

The “two-week wait” is the period between ovulation and when you can reliably take a pregnancy test. During this time, an egg may be fertilized and begin dividing into the tiny cluster of cells that will become your baby, all before nestling into the uterine lining about a week after conception. This means your potential baby is already developing before you even know you’re pregnant.

Right after fertilization, cells begin rapidly multiplying and organizing themselves, laying the groundwork for everything from the heart to the brain. By the time you see those two pink lines on a test, your baby has already reached several important developmental milestones. Any alcohol consumed during the two-week wait can impact these developmental processes and affect:

Embryo implantation in the uterine wall, increasing the risk of miscarriage
The cellular proliferation needed for proper organ formation
The embryo’s ability to establish blood supply connections
Prenatal development of the neural plate, which forms the brain and central nervous system

Mareckova, et. al. found that even moderate alcohol exposure during mid-pregnancy can have long-term effects on brain reward processing in offspring. Prenatal alcohol exposure changed how the brain responds to rewards in nine regions, especially those in the front of the brain responsible for decision-making processes. These challenges are hallmark features of fetal alcohol spectrum disorders.

At Ardu, our alcohol detox services provide the medical support and comfort you need to safely begin your pregnancy journey. Our program includes 24-hour medical monitoring to manage withdrawal symptoms and personalized nutritional therapy to restore your body’s balance.

Reach out to our specialists today.

How much alcohol causes fetal alcohol syndrome?

Fetal alcohol syndrome (FAS) is the most severe form of alcohol-related neurodevelopmental disorders. It’s characterized by distinctive facial abnormalities, growth deficiencies, and central nervous system problems, including cognitive impairment. These birth defects occur when alcohol consumed during pregnancy crosses the placenta and disrupts normal fetal development.

The amount of alcohol that causes FAS depends on the mother’s metabolism, timing of exposure, and the developing baby’s genetic susceptibility. Some babies exposed to heavy drinking show no obvious effects, while others affected by smaller amounts of alcohol experience serious developmental challenges.

According to Hoyme’s diagnostic criteria, too much alcohol can be defined as six or more drinks per week for at least two weeks, or three or more drinks on two separate occasions during pregnancy. The risk of FAS increases with the levels of consumption and blood alcohol levels reached. Standard drinks affect women based on weight, metabolism, and whether alcohol is consumed with food. Binge drinking dangerously elevates blood alcohol concentrations that remain in the amniotic fluid longer than in the maternal bloodstream.

It’s not always easy to quit drinking, even when you’re aware of the potential health risks alcohol carries for your unborn child. We understand this struggle firsthand and stand ready with the medical expertise and genuine care you need.

Support for pregnant women struggling with alcohol addiction

At our rehab center in Provo, Utah, we help women break free from alcohol dependence while creating the healthiest possible environment for their future child. Heavy drinking damages reproductive health in men and women, making conception difficult or impossible.

Our comprehensive approach includes:

Medical detox services with 24-hour monitoring for managing withdrawal safely.
Inpatient treatment in a structured, supportive environment.
Mental health support and dual diagnosis treatment that addresses addiction and underlying psychological challenges.
Nutritional therapy to restore your physical development and reproductive health.
Behavioral therapy to break harmful patterns that drive continued alcohol use.
Family counseling to strengthen your support system.
Holistic approaches to reduce stress and promote healing.

Pregnancy creates a window when overcoming alcohol dependence becomes more challenging and more important. Our specialized women’s detox program provides gender-specific care that addresses the physiological and emotional needs of expectant mothers. Women face distinct health risks from alcohol, including increased vulnerability to liver disease, heart problems, and reproductive issues, all of which receive focused attention in our thorough treatment approach.

Men face similar challenges because alcohol consumption reduces sperm count and motility and impairs sexual function.

Whether you’re concerned about unintended pregnancy or planning for the future, our team creates personalized recovery plans focused on both immediate sobriety and long-term health goals. Contact us online or call (801) 872-8480 to speak with our admissions team about taking the first step toward protecting yourself and your baby.

Brandon Okey is the co-founder of Ardu Recovery Center and is dedicated to empowering people on their journey to sobriety.

Alcohol and pregnancy FAQ

Can I have a glass of wine at 25 weeks pregnant?

Even in later weeks of pregnancy, there’s no known safe amount of alcohol consumption. The Centers for Disease Control and Prevention (CDC) recommends complete abstinence during all stages of pregnancy. While the embryonic stage is particularly vulnerable, alcohol during pregnancy can affect brain development throughout all three trimesters. That occasional drink isn’t worth putting your baby at risk.

Does your body reject alcohol in early pregnancy?

Your body doesn’t reject alcohol during early pregnancy, though some women do experience aversions to alcoholic beverages. This isn’t a protective mechanism. Alcohol crosses the placenta at all levels of consumption. Any alcohol in your bloodstream reaches your developing baby, regardless of whether you experience nausea or other pregnancy symptoms.

Can alcohol cause miscarriage at 1 week?

Alcohol consumption can increase the risk of miscarriage even during the earliest stages of pregnancy. Studies show that drinking during the first weeks of gestation can interfere with the implantation of the embryo in the uterine wall. Heavy drinking or binge drinking particularly elevates this risk, and each successive week of exposure increases miscarriage risk by approximately 8%.

How does maternal consumption of alcohol affect birth weight?

Maternal consumption of alcohol during pregnancy often leads to lower birth weight, even when drinking moderate amounts. This growth restriction occurs because alcohol interferes with the placenta’s ability to deliver nutrients efficiently to the developing baby. Babies with low birth weight face increased risks of breathing problems, difficulty regulating body temperature, and other health complications.

Is there a link between alcohol and infant death syndrome?

There may be a connection between maternal alcohol use and increased risk of sudden infant death syndrome. Studies reveal that prenatal exposure to alcohol affects a baby’s brain development in ways that may disrupt normal breathing regulation during sleep. Alcohol risks follow your baby months after birth, so pregnancy is the perfect time to stop drinking and create a healthier future for you both.

How does alcohol affect a child’s social skills and coordination?

Children exposed to alcohol before birth often show poor coordination and delayed social skills development. Even moderate amounts of alcohol during pregnancy can damage the cerebellum, which controls movement and balance. According to a 2018 study, these children frequently show behavioral issues in classroom settings, struggling with appropriate social interactions and physical activities requiring fine motor control. These effects can persist through childhood and adolescence.

Resources

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Popova S, Dozet D, Shield K, Rehm J, Burd L. Alcohol’s Impact on the Fetus. Nutrients. 2021 Sep 29;13(10):3452. doi: 10.3390/nu13103452. PMID: 34684453; PMCID: PMC8541151.

Ungerer M, Knezovich J, Ramsay M. In utero alcohol exposure, epigenetic changes, and their consequences. Alcohol Res. 2013;35(1):37-46. PMID: 24313163; PMCID: PMC3860424.

Maier SE, West JR. Drinking patterns and alcohol-related birth defects. Alcohol Res Health. 2001;25(3):168-74. PMID: 11810954; PMCID: PMC6707176.

Mareckova, K., Marecek, R., Andryskova, L. et al. Prenatal exposure to alcohol and its impact on reward processing and substance use in adulthood. Transl Psychiatry 14, 220 (2024). https://doi.org/10.1038/s41398-024-02941-9

Hoyme HE, Kalberg WO, Elliott AJ, Blankenship J, Buckley D, Marais AS, Manning MA, Robinson LK, Adam MP, Abdul-Rahman O, Jewett T, Coles CD, Chambers C, Jones KL, Adnams CM, Shah PE, Riley EP, Charness ME, Warren KR, May PA. Updated Clinical Guidelines for Diagnosing Fetal Alcohol Spectrum Disorders. Pediatrics. 2016 Aug;138(2):e20154256. doi: 10.1542/peds.2015-4256. Epub 2016 Jul 27. PMID: 27464676; PMCID: PMC4960726.

Sundermann AC, Zhao S, Young CL, Lam L, Jones SH, Velez Edwards DR, Hartmann KE. Alcohol Use in Pregnancy and Miscarriage: A Systematic Review and Meta-Analysis. Alcohol Clin Exp Res. 2019 Aug;43(8):1606-1616. doi: 10.1111/acer.14124. Epub 2019 Jul 3. PMID: 31194258; PMCID: PMC6677630.

O’Leary CM, Jacoby PJ, Bartu A, D’Antoine H, Bower C. Maternal alcohol use and sudden infant death syndrome and infant mortality excluding SIDS. Pediatrics. 2013 Mar;131(3):e770-8. doi: 10.1542/peds.2012-1907. Epub 2013 Feb 25. PMID: 23439895.

Subramoney S, Eastman E, Adnams C, Stein DJ, Donald KA. The Early Developmental Outcomes of Prenatal Alcohol Exposure: A Review. Front Neurol. 2018 Dec 18;9:1108. doi: 10.3389/fneur.2018.01108. PMID: 30619064; PMCID: PMC6305542.