Anytime something interferes with normal brain development, the most common causes are:
(a) Genetic Conditions. These include things like down syndrome, fragile syndrome.
(b) Problems During Pregnancy. Things that can interfere with foetal brain development include drug use, malnutrition, certain infections etc.
(c) Problems during child birth. Intellectual disability may result if a baby is deprived of oxygen during childbirth or is born extremely pre maturely.
(d) Illness or Injury. Infections like meningitis. whooping cough and measles can and lead to intellectual disability. Severe head injury, near drowning, extreme malnutrition, exposure to toxic substances such as lead etc can also lead to disability.
