Symptoms and causes

The severity of fetal alcohol syndrome symptoms varies, with some children experiencing them to a far greater degree than others. Signs and symptoms of fetal alcohol syndrome may include any mix of physical defects, intellectual or cognitive disabilities, and problems functioning and coping with daily life.

When you're pregnant and you drink alcohol:

  • Alcohol enters your bloodstream and reaches your developing fetus by crossing the placenta
  • Alcohol causes higher blood alcohol concentrations in your developing baby than in your body because a fetus metabolizes alcohol slower than an adult does
  • Alcohol interferes with the delivery of oxygen and optimal nutrition to your developing baby
  • Exposure to alcohol before birth can harm the development of tissues and organs and cause permanent brain damage in your baby

The more you drink while pregnant, the greater the risk to your unborn baby. However, any amount of alcohol puts your baby at risk. Your baby's brain, heart and blood vessels begin to develop in the early weeks of pregnancy, before you may know you're pregnant.

Impairment of facial features, the heart and other organs, including the bones, and the central nervous system may occur as a result of drinking alcohol during the first trimester. That's when these parts of the fetus are in key stages of development. However, the risk is present at any time during pregnancy.

The more alcohol you drink during pregnancy, the greater the chance of problems in your baby. There's no known safe amount of alcohol consumption during pregnancy.

You could put your baby at risk even before you realize you're pregnant. Don't drink alcohol if:

  • You're pregnant
  • You think you might be pregnant
  • You're trying to become pregnant

Problem behaviors not present at birth that can result from having fetal alcohol syndrome (secondary disabilities) may include:

  • Attention deficit/hyperactivity disorder (ADHD)
  • Aggression, inappropriate social conduct, and breaking rules and laws
  • Alcohol or drug misuse
  • Mental health disorders, such as depression, anxiety or eating disorders
  • Problems staying in or completing school
  • Problems with independent living and with employment
  • Inappropriate sexual behaviors
  • Early death by accident, homicide or suicide
May 25, 2017
  1. AskMayoExpert. Fetal alcohol syndrome. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2016.
  2. Fetal alcohol spectrum disorders (FASDs): Facts about FASDs. Centers for Disease Control and Prevention. Accessed March 13, 2017.
  3. Fetal alcohol spectrum disorders (FASDs): Alcohol use in pregnancy. Centers for Disease Control and Prevention. Accessed March 13, 2017.
  4. Fetal alcohol spectrum disorders (FASDs): Secondary conditions. Centers for Disease Control and Prevention. Accessed March 13, 2017.
  5. Fetal alcohol syndrome. American Academy of Family Physicians. Accessed March 13, 2017.
  6. Williams JF, et al. Fetal alcohol spectrum disorders. Pediatrics. 2015;136:e1395.
  7. Effects of alcohol on a fetus. Substance Abuse and Mental Health Services Administration. Accessed March 13, 2017.
  8. Weitzman C, et al. Fetal alcohol spectrum disorder: Overview of management and prognosis. Accessed March 13, 2017.
  9. Wilhoit LF, et al. Fetal alcohol spectrum disorders: Characteristics, complications, and treatment. Community Mental Health Journal. In press. Accessed March 13, 2017.
  10. Weitzman C, et al. Fetal alcohol spectrum disorder: Clinical features and diagnosis. Accessed March 13, 2017.
  11. Hoecker JL (expert opinion). Mayo Clinic, Rochester, Minn. March 25, 2017.