According to the FAS Community Resource Center, most infants with FAS are irritable, with a poor appetite, sleeping problems, hypersensitive to sensory stimulation with a strong startle reflex. They may hyperextend their heads or limbs, and can exhibit either too much muscle tone (hypertonia) or too little muscle tone (hypotonia).
The most serious characteristics of FAS are the invisible symptoms of neurological damage that results from prenatal exposure to alcohol. These symptoms include:
attention and memory deficits
hyperactivity
difficulty with abstract concepts (math, time, money)
poor problem solving skills
difficulty learning from consequences
poor judgment
immature behavior with poor impulse control
Additionally, there are sensory integration issues with most children with FAS. They are more sensitive to light, sound and touch.