Module 2: Effects of Alcohol on the Fetus
Central Nervous System Damage
The brain and spinal cord make up the CNS. The CNS can be damaged at any time during pregnancy. It is one of the
first systems to form after conception and continues developing after birth.
The CNS may be affected in many complex ways. CNS damage can cause
learning and behavior problems. For example, children with an FASD may have
acute sensitivity to sound, light, touch, and temperature; irritability; attention problems; and jitteriness.10,11 Neurotransmitters are chemical messengers that allow communication to occur among nerve cells in the brain. This occurs thousands of times a day and is responsible for brain function. Prenatal exposure to alcohol significantly disrupts many neurotransmitter systems.
Prenatal alcohol exposure also may reduce serotonin levels.12 Serotonin is a chemical that plays a role in regulating mood, aggression, sexual activity, sleep, and sensitivity to pain. Fetal alcohol exposure has also been linked to attention and hyperactivity problems caused by dopamine abnormalities.13 Another chemical, dopamine, regulates motor function, pleasure and reward, and attention.
Studies of prenatal alcohol exposure have consistently found impaired motor control. Motor control is a complex function influenced by the CNS. It also involves the peripheral nervous system, which provides sensory feedback to the CNS. The vestibular system plays a role as well. It is located in the inner
ear and is involved in a person's sense of balance. Defects in any of these systems can affect motor control.12
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